summaryrefslogtreecommitdiffstats
path: root/src/corelib/tools/qstring.cpp
blob: bb13ee94b8b82938e7edbda7ad8ff860ce8efad3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
5131
5132
5133
5134
5135
5136
5137
5138
5139
5140
5141
5142
5143
5144
5145
5146
5147
5148
5149
5150
5151
5152
5153
5154
5155
5156
5157
5158
5159
5160
5161
5162
5163
5164
5165
5166
5167
5168
5169
5170
5171
5172
5173
5174
5175
5176
5177
5178
5179
5180
5181
5182
5183
5184
5185
5186
5187
5188
5189
5190
5191
5192
5193
5194
5195
5196
5197
5198
5199
5200
5201
5202
5203
5204
5205
5206
5207
5208
5209
5210
5211
5212
5213
5214
5215
5216
5217
5218
5219
5220
5221
5222
5223
5224
5225
5226
5227
5228
5229
5230
5231
5232
5233
5234
5235
5236
5237
5238
5239
5240
5241
5242
5243
5244
5245
5246
5247
5248
5249
5250
5251
5252
5253
5254
5255
5256
5257
5258
5259
5260
5261
5262
5263
5264
5265
5266
5267
5268
5269
5270
5271
5272
5273
5274
5275
5276
5277
5278
5279
5280
5281
5282
5283
5284
5285
5286
5287
5288
5289
5290
5291
5292
5293
5294
5295
5296
5297
5298
5299
5300
5301
5302
5303
5304
5305
5306
5307
5308
5309
5310
5311
5312
5313
5314
5315
5316
5317
5318
5319
5320
5321
5322
5323
5324
5325
5326
5327
5328
5329
5330
5331
5332
5333
5334
5335
5336
5337
5338
5339
5340
5341
5342
5343
5344
5345
5346
5347
5348
5349
5350
5351
5352
5353
5354
5355
5356
5357
5358
5359
5360
5361
5362
5363
5364
5365
5366
5367
5368
5369
5370
5371
5372
5373
5374
5375
5376
5377
5378
5379
5380
5381
5382
5383
5384
5385
5386
5387
5388
5389
5390
5391
5392
5393
5394
5395
5396
5397
5398
5399
5400
5401
5402
5403
5404
5405
5406
5407
5408
5409
5410
5411
5412
5413
5414
5415
5416
5417
5418
5419
5420
5421
5422
5423
5424
5425
5426
5427
5428
5429
5430
5431
5432
5433
5434
5435
5436
5437
5438
5439
5440
5441
5442
5443
5444
5445
5446
5447
5448
5449
5450
5451
5452
5453
5454
5455
5456
5457
5458
5459
5460
5461
5462
5463
5464
5465
5466
5467
5468
5469
5470
5471
5472
5473
5474
5475
5476
5477
5478
5479
5480
5481
5482
5483
5484
5485
5486
5487
5488
5489
5490
5491
5492
5493
5494
5495
5496
5497
5498
5499
5500
5501
5502
5503
5504
5505
5506
5507
5508
5509
5510
5511
5512
5513
5514
5515
5516
5517
5518
5519
5520
5521
5522
5523
5524
5525
5526
5527
5528
5529
5530
5531
5532
5533
5534
5535
5536
5537
5538
5539
5540
5541
5542
5543
5544
5545
5546
5547
5548
5549
5550
5551
5552
5553
5554
5555
5556
5557
5558
5559
5560
5561
5562
5563
5564
5565
5566
5567
5568
5569
5570
5571
5572
5573
5574
5575
5576
5577
5578
5579
5580
5581
5582
5583
5584
5585
5586
5587
5588
5589
5590
5591
5592
5593
5594
5595
5596
5597
5598
5599
5600
5601
5602
5603
5604
5605
5606
5607
5608
5609
5610
5611
5612
5613
5614
5615
5616
5617
5618
5619
5620
5621
5622
5623
5624
5625
5626
5627
5628
5629
5630
5631
5632
5633
5634
5635
5636
5637
5638
5639
5640
5641
5642
5643
5644
5645
5646
5647
5648
5649
5650
5651
5652
5653
5654
5655
5656
5657
5658
5659
5660
5661
5662
5663
5664
5665
5666
5667
5668
5669
5670
5671
5672
5673
5674
5675
5676
5677
5678
5679
5680
5681
5682
5683
5684
5685
5686
5687
5688
5689
5690
5691
5692
5693
5694
5695
5696
5697
5698
5699
5700
5701
5702
5703
5704
5705
5706
5707
5708
5709
5710
5711
5712
5713
5714
5715
5716
5717
5718
5719
5720
5721
5722
5723
5724
5725
5726
5727
5728
5729
5730
5731
5732
5733
5734
5735
5736
5737
5738
5739
5740
5741
5742
5743
5744
5745
5746
5747
5748
5749
5750
5751
5752
5753
5754
5755
5756
5757
5758
5759
5760
5761
5762
5763
5764
5765
5766
5767
5768
5769
5770
5771
5772
5773
5774
5775
5776
5777
5778
5779
5780
5781
5782
5783
5784
5785
5786
5787
5788
5789
5790
5791
5792
5793
5794
5795
5796
5797
5798
5799
5800
5801
5802
5803
5804
5805
5806
5807
5808
5809
5810
5811
5812
5813
5814
5815
5816
5817
5818
5819
5820
5821
5822
5823
5824
5825
5826
5827
5828
5829
5830
5831
5832
5833
5834
5835
5836
5837
5838
5839
5840
5841
5842
5843
5844
5845
5846
5847
5848
5849
5850
5851
5852
5853
5854
5855
5856
5857
5858
5859
5860
5861
5862
5863
5864
5865
5866
5867
5868
5869
5870
5871
5872
5873
5874
5875
5876
5877
5878
5879
5880
5881
5882
5883
5884
5885
5886
5887
5888
5889
5890
5891
5892
5893
5894
5895
5896
5897
5898
5899
5900
5901
5902
5903
5904
5905
5906
5907
5908
5909
5910
5911
5912
5913
5914
5915
5916
5917
5918
5919
5920
5921
5922
5923
5924
5925
5926
5927
5928
5929
5930
5931
5932
5933
5934
5935
5936
5937
5938
5939
5940
5941
5942
5943
5944
5945
5946
5947
5948
5949
5950
5951
5952
5953
5954
5955
5956
5957
5958
5959
5960
5961
5962
5963
5964
5965
5966
5967
5968
5969
5970
5971
5972
5973
5974
5975
5976
5977
5978
5979
5980
5981
5982
5983
5984
5985
5986
5987
5988
5989
5990
5991
5992
5993
5994
5995
5996
5997
5998
5999
6000
6001
6002
6003
6004
6005
6006
6007
6008
6009
6010
6011
6012
6013
6014
6015
6016
6017
6018
6019
6020
6021
6022
6023
6024
6025
6026
6027
6028
6029
6030
6031
6032
6033
6034
6035
6036
6037
6038
6039
6040
6041
6042
6043
6044
6045
6046
6047
6048
6049
6050
6051
6052
6053
6054
6055
6056
6057
6058
6059
6060
6061
6062
6063
6064
6065
6066
6067
6068
6069
6070
6071
6072
6073
6074
6075
6076
6077
6078
6079
6080
6081
6082
6083
6084
6085
6086
6087
6088
6089
6090
6091
6092
6093
6094
6095
6096
6097
6098
6099
6100
6101
6102
6103
6104
6105
6106
6107
6108
6109
6110
6111
6112
6113
6114
6115
6116
6117
6118
6119
6120
6121
6122
6123
6124
6125
6126
6127
6128
6129
6130
6131
6132
6133
6134
6135
6136
6137
6138
6139
6140
6141
6142
6143
6144
6145
6146
6147
6148
6149
6150
6151
6152
6153
6154
6155
6156
6157
6158
6159
6160
6161
6162
6163
6164
6165
6166
6167
6168
6169
6170
6171
6172
6173
6174
6175
6176
6177
6178
6179
6180
6181
6182
6183
6184
6185
6186
6187
6188
6189
6190
6191
6192
6193
6194
6195
6196
6197
6198
6199
6200
6201
6202
6203
6204
6205
6206
6207
6208
6209
6210
6211
6212
6213
6214
6215
6216
6217
6218
6219
6220
6221
6222
6223
6224
6225
6226
6227
6228
6229
6230
6231
6232
6233
6234
6235
6236
6237
6238
6239
6240
6241
6242
6243
6244
6245
6246
6247
6248
6249
6250
6251
6252
6253
6254
6255
6256
6257
6258
6259
6260
6261
6262
6263
6264
6265
6266
6267
6268
6269
6270
6271
6272
6273
6274
6275
6276
6277
6278
6279
6280
6281
6282
6283
6284
6285
6286
6287
6288
6289
6290
6291
6292
6293
6294
6295
6296
6297
6298
6299
6300
6301
6302
6303
6304
6305
6306
6307
6308
6309
6310
6311
6312
6313
6314
6315
6316
6317
6318
6319
6320
6321
6322
6323
6324
6325
6326
6327
6328
6329
6330
6331
6332
6333
6334
6335
6336
6337
6338
6339
6340
6341
6342
6343
6344
6345
6346
6347
6348
6349
6350
6351
6352
6353
6354
6355
6356
6357
6358
6359
6360
6361
6362
6363
6364
6365
6366
6367
6368
6369
6370
6371
6372
6373
6374
6375
6376
6377
6378
6379
6380
6381
6382
6383
6384
6385
6386
6387
6388
6389
6390
6391
6392
6393
6394
6395
6396
6397
6398
6399
6400
6401
6402
6403
6404
6405
6406
6407
6408
6409
6410
6411
6412
6413
6414
6415
6416
6417
6418
6419
6420
6421
6422
6423
6424
6425
6426
6427
6428
6429
6430
6431
6432
6433
6434
6435
6436
6437
6438
6439
6440
6441
6442
6443
6444
6445
6446
6447
6448
6449
6450
6451
6452
6453
6454
6455
6456
6457
6458
6459
6460
6461
6462
6463
6464
6465
6466
6467
6468
6469
6470
6471
6472
6473
6474
6475
6476
6477
6478
6479
6480
6481
6482
6483
6484
6485
6486
6487
6488
6489
6490
6491
6492
6493
6494
6495
6496
6497
6498
6499
6500
6501
6502
6503
6504
6505
6506
6507
6508
6509
6510
6511
6512
6513
6514
6515
6516
6517
6518
6519
6520
6521
6522
6523
6524
6525
6526
6527
6528
6529
6530
6531
6532
6533
6534
6535
6536
6537
6538
6539
6540
6541
6542
6543
6544
6545
6546
6547
6548
6549
6550
6551
6552
6553
6554
6555
6556
6557
6558
6559
6560
6561
6562
6563
6564
6565
6566
6567
6568
6569
6570
6571
6572
6573
6574
6575
6576
6577
6578
6579
6580
6581
6582
6583
6584
6585
6586
6587
6588
6589
6590
6591
6592
6593
6594
6595
6596
6597
6598
6599
6600
6601
6602
6603
6604
6605
6606
6607
6608
6609
6610
6611
6612
6613
6614
6615
6616
6617
6618
6619
6620
6621
6622
6623
6624
6625
6626
6627
6628
6629
6630
6631
6632
6633
6634
6635
6636
6637
6638
6639
6640
6641
6642
6643
6644
6645
6646
6647
6648
6649
6650
6651
6652
6653
6654
6655
6656
6657
6658
6659
6660
6661
6662
6663
6664
6665
6666
6667
6668
6669
6670
6671
6672
6673
6674
6675
6676
6677
6678
6679
6680
6681
6682
6683
6684
6685
6686
6687
6688
6689
6690
6691
6692
6693
6694
6695
6696
6697
6698
6699
6700
6701
6702
6703
6704
6705
6706
6707
6708
6709
6710
6711
6712
6713
6714
6715
6716
6717
6718
6719
6720
6721
6722
6723
6724
6725
6726
6727
6728
6729
6730
6731
6732
6733
6734
6735
6736
6737
6738
6739
6740
6741
6742
6743
6744
6745
6746
6747
6748
6749
6750
6751
6752
6753
6754
6755
6756
6757
6758
6759
6760
6761
6762
6763
6764
6765
6766
6767
6768
6769
6770
6771
6772
6773
6774
6775
6776
6777
6778
6779
6780
6781
6782
6783
6784
6785
6786
6787
6788
6789
6790
6791
6792
6793
6794
6795
6796
6797
6798
6799
6800
6801
6802
6803
6804
6805
6806
6807
6808
6809
6810
6811
6812
6813
6814
6815
6816
6817
6818
6819
6820
6821
6822
6823
6824
6825
6826
6827
6828
6829
6830
6831
6832
6833
6834
6835
6836
6837
6838
6839
6840
6841
6842
6843
6844
6845
6846
6847
6848
6849
6850
6851
6852
6853
6854
6855
6856
6857
6858
6859
6860
6861
6862
6863
6864
6865
6866
6867
6868
6869
6870
6871
6872
6873
6874
6875
6876
6877
6878
6879
6880
6881
6882
6883
6884
6885
6886
6887
6888
6889
6890
6891
6892
6893
6894
6895
6896
6897
6898
6899
6900
6901
6902
6903
6904
6905
6906
6907
6908
6909
6910
6911
6912
6913
6914
6915
6916
6917
6918
6919
6920
6921
6922
6923
6924
6925
6926
6927
6928
6929
6930
6931
6932
6933
6934
6935
6936
6937
6938
6939
6940
6941
6942
6943
6944
6945
6946
6947
6948
6949
6950
6951
6952
6953
6954
6955
6956
6957
6958
6959
6960
6961
6962
6963
6964
6965
6966
6967
6968
6969
6970
6971
6972
6973
6974
6975
6976
6977
6978
6979
6980
6981
6982
6983
6984
6985
6986
6987
6988
6989
6990
6991
6992
6993
6994
6995
6996
6997
6998
6999
7000
7001
7002
7003
7004
7005
7006
7007
7008
7009
7010
7011
7012
7013
7014
7015
7016
7017
7018
7019
7020
7021
7022
7023
7024
7025
7026
7027
7028
7029
7030
7031
7032
7033
7034
7035
7036
7037
7038
7039
7040
7041
7042
7043
7044
7045
7046
7047
7048
7049
7050
7051
7052
7053
7054
7055
7056
7057
7058
7059
7060
7061
7062
7063
7064
7065
7066
7067
7068
7069
7070
7071
7072
7073
7074
7075
7076
7077
7078
7079
7080
7081
7082
7083
7084
7085
7086
7087
7088
7089
7090
7091
7092
7093
7094
7095
7096
7097
7098
7099
7100
7101
7102
7103
7104
7105
7106
7107
7108
7109
7110
7111
7112
7113
7114
7115
7116
7117
7118
7119
7120
7121
7122
7123
7124
7125
7126
7127
7128
7129
7130
7131
7132
7133
7134
7135
7136
7137
7138
7139
7140
7141
7142
7143
7144
7145
7146
7147
7148
7149
7150
7151
7152
7153
7154
7155
7156
7157
7158
7159
7160
7161
7162
7163
7164
7165
7166
7167
7168
7169
7170
7171
7172
7173
7174
7175
7176
7177
7178
7179
7180
7181
7182
7183
7184
7185
7186
7187
7188
7189
7190
7191
7192
7193
7194
7195
7196
7197
7198
7199
7200
7201
7202
7203
7204
7205
7206
7207
7208
7209
7210
7211
7212
7213
7214
7215
7216
7217
7218
7219
7220
7221
7222
7223
7224
7225
7226
7227
7228
7229
7230
7231
7232
7233
7234
7235
7236
7237
7238
7239
7240
7241
7242
7243
7244
7245
7246
7247
7248
7249
7250
7251
7252
7253
7254
7255
7256
7257
7258
7259
7260
7261
7262
7263
7264
7265
7266
7267
7268
7269
7270
7271
7272
7273
7274
7275
7276
7277
7278
7279
7280
7281
7282
7283
7284
7285
7286
7287
7288
7289
7290
7291
7292
7293
7294
7295
7296
7297
7298
7299
7300
7301
7302
7303
7304
7305
7306
7307
7308
7309
7310
7311
7312
7313
7314
7315
7316
7317
7318
7319
7320
7321
7322
7323
7324
7325
7326
7327
7328
7329
7330
7331
7332
7333
7334
7335
7336
7337
7338
7339
7340
7341
7342
7343
7344
7345
7346
7347
7348
7349
7350
7351
7352
7353
7354
7355
7356
7357
7358
7359
7360
7361
7362
7363
7364
7365
7366
7367
7368
7369
7370
7371
7372
7373
7374
7375
7376
7377
7378
7379
7380
7381
7382
7383
7384
7385
7386
7387
7388
7389
7390
7391
7392
7393
7394
7395
7396
7397
7398
7399
7400
7401
7402
7403
7404
7405
7406
7407
7408
7409
7410
7411
7412
7413
7414
7415
7416
7417
7418
7419
7420
7421
7422
7423
7424
7425
7426
7427
7428
7429
7430
7431
7432
7433
7434
7435
7436
7437
7438
7439
7440
7441
7442
7443
7444
7445
7446
7447
7448
7449
7450
7451
7452
7453
7454
7455
7456
7457
7458
7459
7460
7461
7462
7463
7464
7465
7466
7467
7468
7469
7470
7471
7472
7473
7474
7475
7476
7477
7478
7479
7480
7481
7482
7483
7484
7485
7486
7487
7488
7489
7490
7491
7492
7493
7494
7495
7496
7497
7498
7499
7500
7501
7502
7503
7504
7505
7506
7507
7508
7509
7510
7511
7512
7513
7514
7515
7516
7517
7518
7519
7520
7521
7522
7523
7524
7525
7526
7527
7528
7529
7530
7531
7532
7533
7534
7535
7536
7537
7538
7539
7540
7541
7542
7543
7544
7545
7546
7547
7548
7549
7550
7551
7552
7553
7554
7555
7556
7557
7558
7559
7560
7561
7562
7563
7564
7565
7566
7567
7568
7569
7570
7571
7572
7573
7574
7575
7576
7577
7578
7579
7580
7581
7582
7583
7584
7585
7586
7587
7588
7589
7590
7591
7592
7593
7594
7595
7596
7597
7598
7599
7600
7601
7602
7603
7604
7605
7606
7607
7608
7609
7610
7611
7612
7613
7614
7615
7616
7617
7618
7619
7620
7621
7622
7623
7624
7625
7626
7627
7628
7629
7630
7631
7632
7633
7634
7635
7636
7637
7638
7639
7640
7641
7642
7643
7644
7645
7646
7647
7648
7649
7650
7651
7652
7653
7654
7655
7656
7657
7658
7659
7660
7661
7662
7663
7664
7665
7666
7667
7668
7669
7670
7671
7672
7673
7674
7675
7676
7677
7678
7679
7680
7681
7682
7683
7684
7685
7686
7687
7688
7689
7690
7691
7692
7693
7694
7695
7696
7697
7698
7699
7700
7701
7702
7703
7704
7705
7706
7707
7708
7709
7710
7711
7712
7713
7714
7715
7716
7717
7718
7719
7720
7721
7722
7723
7724
7725
7726
7727
7728
7729
7730
7731
7732
7733
7734
7735
7736
7737
7738
7739
7740
7741
7742
7743
7744
7745
7746
7747
7748
7749
7750
7751
7752
7753
7754
7755
7756
7757
7758
7759
7760
7761
7762
7763
7764
7765
7766
7767
7768
7769
7770
7771
7772
7773
7774
7775
7776
7777
7778
7779
7780
7781
7782
7783
7784
7785
7786
7787
7788
7789
7790
7791
7792
7793
7794
7795
7796
7797
7798
7799
7800
7801
7802
7803
7804
7805
7806
7807
7808
7809
7810
7811
7812
7813
7814
7815
7816
7817
7818
7819
7820
7821
7822
7823
7824
7825
7826
7827
7828
7829
7830
7831
7832
7833
7834
7835
7836
7837
7838
7839
7840
7841
7842
7843
7844
7845
7846
7847
7848
7849
7850
7851
7852
7853
7854
7855
7856
7857
7858
7859
7860
7861
7862
7863
7864
7865
7866
7867
7868
7869
7870
7871
7872
7873
7874
7875
7876
7877
7878
7879
7880
7881
7882
7883
7884
7885
7886
7887
7888
7889
7890
7891
7892
7893
7894
7895
7896
7897
7898
7899
7900
7901
7902
7903
7904
7905
7906
7907
7908
7909
7910
7911
7912
7913
7914
7915
7916
7917
7918
7919
7920
7921
7922
7923
7924
7925
7926
7927
7928
7929
7930
7931
7932
7933
7934
7935
7936
7937
7938
7939
7940
7941
7942
7943
7944
7945
7946
7947
7948
7949
7950
7951
7952
7953
7954
7955
7956
7957
7958
7959
7960
7961
7962
7963
7964
7965
7966
7967
7968
7969
7970
7971
7972
7973
7974
7975
7976
7977
7978
7979
7980
7981
7982
7983
7984
7985
7986
7987
7988
7989
7990
7991
7992
7993
7994
7995
7996
7997
7998
7999
8000
8001
8002
8003
8004
8005
8006
8007
8008
8009
8010
8011
8012
8013
8014
8015
8016
8017
8018
8019
8020
8021
8022
8023
8024
8025
8026
8027
8028
8029
8030
8031
8032
8033
8034
8035
8036
8037
8038
8039
8040
8041
8042
8043
8044
8045
8046
8047
8048
8049
8050
8051
8052
8053
8054
8055
8056
8057
8058
8059
8060
8061
8062
8063
8064
8065
8066
8067
8068
8069
8070
8071
8072
8073
8074
8075
8076
8077
8078
8079
8080
8081
8082
8083
8084
8085
8086
8087
8088
8089
8090
8091
8092
8093
8094
8095
8096
8097
8098
8099
8100
8101
8102
8103
8104
8105
8106
8107
8108
8109
8110
8111
8112
8113
8114
8115
8116
8117
8118
8119
8120
8121
8122
8123
8124
8125
8126
8127
8128
8129
8130
8131
8132
8133
8134
8135
8136
8137
8138
8139
8140
8141
8142
8143
8144
8145
8146
8147
8148
8149
8150
8151
8152
8153
8154
8155
8156
8157
8158
8159
8160
8161
8162
8163
8164
8165
8166
8167
8168
8169
8170
8171
8172
8173
8174
8175
8176
8177
8178
8179
8180
8181
8182
8183
8184
8185
8186
8187
8188
8189
8190
8191
8192
8193
8194
8195
8196
8197
8198
8199
8200
8201
8202
8203
8204
8205
8206
8207
8208
8209
8210
8211
8212
8213
8214
8215
8216
8217
8218
8219
8220
8221
8222
8223
8224
8225
8226
8227
8228
8229
8230
8231
8232
8233
8234
8235
8236
8237
8238
8239
8240
8241
8242
8243
8244
8245
8246
8247
8248
8249
8250
8251
8252
8253
8254
8255
8256
8257
8258
8259
8260
8261
8262
8263
8264
8265
8266
8267
8268
8269
8270
8271
8272
8273
8274
8275
8276
8277
8278
8279
8280
8281
8282
8283
8284
8285
8286
8287
8288
8289
8290
8291
8292
8293
8294
8295
8296
8297
8298
8299
8300
8301
8302
8303
8304
8305
8306
8307
8308
8309
8310
8311
8312
8313
8314
8315
8316
8317
8318
8319
8320
8321
8322
8323
8324
8325
8326
8327
8328
8329
8330
8331
8332
8333
8334
8335
8336
8337
8338
8339
8340
8341
8342
8343
8344
8345
8346
8347
8348
8349
8350
8351
8352
8353
8354
8355
8356
8357
8358
8359
8360
8361
8362
8363
8364
8365
8366
8367
8368
8369
8370
8371
8372
8373
8374
8375
8376
8377
8378
8379
8380
8381
8382
8383
8384
8385
8386
8387
8388
8389
8390
8391
8392
8393
8394
8395
8396
8397
8398
8399
8400
8401
8402
8403
8404
8405
8406
8407
8408
8409
8410
8411
8412
8413
8414
8415
8416
8417
8418
8419
8420
8421
8422
8423
8424
8425
8426
8427
8428
8429
8430
8431
8432
8433
8434
8435
8436
8437
8438
8439
8440
8441
8442
8443
8444
8445
8446
8447
8448
8449
8450
8451
8452
8453
8454
8455
8456
8457
8458
8459
8460
8461
8462
8463
8464
8465
8466
8467
8468
8469
8470
8471
8472
8473
8474
8475
8476
8477
8478
8479
8480
8481
8482
8483
8484
8485
8486
8487
8488
8489
8490
8491
8492
8493
8494
8495
8496
8497
8498
8499
8500
8501
8502
8503
8504
8505
8506
8507
8508
8509
8510
8511
8512
8513
8514
8515
8516
8517
8518
8519
8520
8521
8522
8523
8524
8525
8526
8527
8528
8529
8530
8531
8532
8533
8534
8535
8536
8537
8538
8539
8540
8541
8542
8543
8544
8545
8546
8547
8548
8549
8550
8551
8552
8553
8554
8555
8556
8557
8558
8559
8560
8561
8562
8563
8564
8565
8566
8567
8568
8569
8570
8571
8572
8573
8574
8575
8576
8577
8578
8579
8580
8581
8582
8583
8584
8585
8586
8587
8588
8589
8590
8591
8592
8593
8594
8595
8596
8597
8598
8599
8600
8601
8602
8603
8604
8605
8606
8607
8608
8609
8610
8611
8612
8613
8614
8615
8616
8617
8618
8619
8620
8621
8622
8623
8624
8625
8626
8627
8628
8629
8630
8631
8632
8633
8634
8635
8636
8637
8638
8639
8640
8641
8642
8643
8644
8645
8646
8647
8648
8649
8650
8651
8652
8653
8654
8655
8656
8657
8658
8659
8660
8661
8662
8663
8664
8665
8666
8667
8668
8669
8670
8671
8672
8673
8674
8675
8676
8677
8678
8679
8680
8681
8682
8683
8684
8685
8686
8687
8688
8689
8690
8691
8692
8693
8694
8695
8696
8697
8698
8699
8700
8701
8702
8703
8704
8705
8706
8707
8708
8709
8710
8711
8712
8713
8714
8715
8716
8717
8718
8719
8720
8721
8722
8723
8724
8725
8726
8727
8728
8729
8730
8731
8732
8733
8734
8735
8736
8737
8738
8739
8740
8741
8742
8743
8744
8745
8746
8747
8748
8749
8750
8751
8752
8753
8754
8755
8756
8757
8758
8759
8760
8761
8762
8763
8764
8765
8766
8767
8768
8769
8770
8771
8772
8773
8774
8775
8776
8777
8778
8779
8780
8781
8782
8783
8784
8785
8786
8787
8788
8789
8790
8791
8792
8793
8794
8795
8796
8797
8798
8799
8800
8801
8802
8803
8804
8805
8806
8807
8808
8809
8810
8811
8812
8813
8814
8815
8816
8817
8818
8819
8820
8821
8822
8823
8824
8825
8826
8827
8828
8829
8830
8831
8832
8833
8834
8835
8836
8837
8838
8839
8840
8841
8842
8843
8844
8845
8846
8847
8848
8849
8850
8851
8852
8853
8854
8855
8856
8857
8858
8859
8860
8861
8862
8863
8864
8865
8866
8867
8868
8869
8870
8871
8872
8873
8874
8875
8876
8877
8878
8879
8880
8881
8882
8883
8884
8885
8886
8887
8888
8889
8890
8891
8892
8893
8894
8895
8896
8897
8898
8899
8900
8901
8902
8903
8904
8905
8906
8907
8908
8909
8910
8911
8912
8913
8914
8915
8916
8917
8918
8919
8920
8921
8922
8923
8924
8925
8926
8927
8928
8929
8930
8931
8932
8933
8934
8935
8936
8937
8938
8939
8940
8941
8942
8943
8944
8945
8946
8947
8948
8949
8950
8951
8952
8953
8954
8955
8956
8957
8958
8959
8960
8961
8962
8963
8964
8965
8966
8967
8968
8969
8970
8971
8972
8973
8974
8975
8976
8977
8978
8979
8980
8981
8982
8983
8984
8985
8986
8987
8988
8989
8990
8991
8992
8993
8994
8995
8996
8997
8998
8999
9000
9001
9002
9003
9004
9005
9006
9007
9008
9009
9010
9011
9012
9013
9014
9015
9016
9017
9018
9019
9020
9021
9022
9023
9024
9025
9026
9027
9028
9029
9030
9031
9032
9033
9034
9035
9036
9037
9038
9039
9040
9041
9042
9043
9044
9045
9046
9047
9048
9049
9050
9051
9052
9053
9054
9055
9056
9057
9058
9059
9060
9061
9062
9063
9064
9065
9066
9067
9068
9069
9070
9071
9072
9073
9074
9075
9076
9077
9078
9079
9080
9081
9082
9083
9084
9085
9086
9087
9088
9089
9090
9091
9092
9093
9094
9095
9096
9097
9098
9099
9100
9101
9102
9103
9104
9105
9106
9107
9108
9109
9110
9111
9112
9113
9114
9115
9116
9117
9118
9119
9120
9121
9122
9123
9124
9125
9126
9127
9128
9129
9130
9131
9132
9133
9134
9135
9136
9137
9138
9139
9140
9141
9142
9143
9144
9145
9146
9147
9148
9149
9150
9151
9152
9153
9154
9155
9156
9157
9158
9159
9160
9161
9162
/****************************************************************************
**
** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** GNU Lesser General Public License Usage
** This file may be used under the terms of the GNU Lesser General Public
** License version 2.1 as published by the Free Software Foundation and
** appearing in the file LICENSE.LGPL included in the packaging of this
** file. Please review the following information to ensure the GNU Lesser
** General Public License version 2.1 requirements will be met:
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights. These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU General
** Public License version 3.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of this
** file. Please review the following information to ensure the GNU General
** Public License version 3.0 requirements will be met:
** http://www.gnu.org/copyleft/gpl.html.
**
** Other Usage
** Alternatively, this file may be used in accordance with the terms and
** conditions contained in a signed written agreement between you and Nokia.
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qstringlist.h"
#include "qregexp.h"
#include "qunicodetables_p.h"
#ifndef QT_NO_TEXTCODEC
#include <qtextcodec.h>
#endif
#include <private/qutfcodec_p.h>
#include "qsimd_p.h"
#include <qdatastream.h>
#include <qlist.h>
#include "qlocale.h"
#include "qlocale_p.h"
#include "qstringmatcher.h"
#include "qvarlengtharray.h"
#include "qtools_p.h"
#include "qhash.h"
#include "qdebug.h"
#include "qendian.h"

#ifdef Q_OS_MAC
#include <private/qcore_mac_p.h>
#endif

#include <private/qfunctions_p.h>

#if defined(Q_OS_WINCE)
#include <windows.h>
#include <winnls.h>
#endif

#ifdef Q_OS_SYMBIAN
#include <e32cmn.h>
#endif

#include <limits.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>

#ifdef truncate
#undef truncate
#endif

#include "qchar.cpp"
#include "qstringmatcher.cpp"

#ifndef LLONG_MAX
#define LLONG_MAX qint64_C(9223372036854775807)
#endif
#ifndef LLONG_MIN
#define LLONG_MIN (-LLONG_MAX - qint64_C(1))
#endif
#ifndef ULLONG_MAX
#define ULLONG_MAX quint64_C(18446744073709551615)
#endif

QT_BEGIN_NAMESPACE

#ifndef QT_NO_TEXTCODEC
QTextCodec *QString::codecForCStrings;
#endif

#ifdef QT3_SUPPORT
static QHash<void *, QByteArray> *asciiCache = 0;
#endif

#ifdef QT_USE_ICU
// qlocale_icu.cpp
extern bool qt_ucol_strcoll(const QChar *source, int sourceLength, const QChar *target, int targetLength, int *result);
#endif


// internal
int qFindString(const QChar *haystack, int haystackLen, int from,
    const QChar *needle, int needleLen, Qt::CaseSensitivity cs);
int qFindStringBoyerMoore(const QChar *haystack, int haystackLen, int from,
    const QChar *needle, int needleLen, Qt::CaseSensitivity cs);
static inline int qt_last_index_of(const QChar *haystack, int haystackLen, const QChar &needle,
                                   int from, Qt::CaseSensitivity cs);
static inline int qt_string_count(const QChar *haystack, int haystackLen,
                                  const QChar *needle, int needleLen,
                                  Qt::CaseSensitivity cs);
static inline int qt_string_count(const QChar *haystack, int haystackLen,
                                  const QChar &needle, Qt::CaseSensitivity cs);
static inline int qt_find_latin1_string(const QChar *hay, int size, const QLatin1String &needle,
                                        int from, Qt::CaseSensitivity cs);
static inline bool qt_starts_with(const QChar *haystack, int haystackLen,
                                  const QChar *needle, int needleLen, Qt::CaseSensitivity cs);
static inline bool qt_starts_with(const QChar *haystack, int haystackLen,
                                  const QLatin1String &needle, Qt::CaseSensitivity cs);
static inline bool qt_ends_with(const QChar *haystack, int haystackLen,
                                const QChar *needle, int needleLen, Qt::CaseSensitivity cs);
static inline bool qt_ends_with(const QChar *haystack, int haystackLen,
                                const QLatin1String &needle, Qt::CaseSensitivity cs);

// Unicode case-insensitive comparison
static int ucstricmp(const ushort *a, const ushort *ae, const ushort *b, const ushort *be)
{
    if (a == b)
        return (ae - be);
    if (a == 0)
        return 1;
    if (b == 0)
        return -1;

    const ushort *e = ae;
    if (be - b < ae - a)
        e = a + (be - b);

    uint alast = 0;
    uint blast = 0;
    while (a < e) {
//         qDebug() << hex << alast << blast;
//         qDebug() << hex << "*a=" << *a << "alast=" << alast << "folded=" << foldCase (*a, alast);
//         qDebug() << hex << "*b=" << *b << "blast=" << blast << "folded=" << foldCase (*b, blast);
        int diff = foldCase(*a, alast) - foldCase(*b, blast);
        if ((diff))
            return diff;
        ++a;
        ++b;
    }
    if (a == ae) {
        if (b == be)
            return 0;
        return -1;
    }
    return 1;
}

// Case-insensitive comparison between a Unicode string and a QLatin1String
static int ucstricmp(const ushort *a, const ushort *ae, const uchar *b)
{
    if (a == 0) {
        if (b == 0)
            return 0;
        return 1;
    }
    if (b == 0)
        return -1;

    while (a < ae && *b) {
        int diff = foldCase(*a) - foldCase(*b);
        if ((diff))
            return diff;
        ++a;
        ++b;
    }
    if (a == ae) {
        if (!*b)
            return 0;
        return -1;
    }
    return 1;
}

// Unicode case-sensitive compare two same-sized strings
static int ucstrncmp(const QChar *a, const QChar *b, int l)
{
    while (l-- && *a == *b)
        a++,b++;
    if (l==-1)
        return 0;
    return a->unicode() - b->unicode();
}

// Unicode case-sensitive comparison
static int ucstrcmp(const QChar *a, int alen, const QChar *b, int blen)
{
    if (a == b && alen == blen)
        return 0;
    int l = qMin(alen, blen);
    int cmp = ucstrncmp(a, b, l);
    return cmp ? cmp : (alen-blen);
}

// Unicode case-insensitive compare two same-sized strings
static int ucstrnicmp(const ushort *a, const ushort *b, int l)
{
    return ucstricmp(a, a + l, b, b + l);
}

// Benchmarking indicates that doing memcmp is much slower than
// executing the comparison ourselves.
//
// The profiling was done on a population of calls to qMemEquals, generated
// during a run of the demo browser. The profile of the data (32-bit x86
// Linux) was:
//
//  total number of comparisons: 21353
//  longest string compared: 95
//  average comparison length: 14.8786
//  cache-line crosses: 5661 (13.3%)
//  alignment histogram:
//   0xXXX0 = 512 (1.2%) strings, 0 (0.0%) of which same-aligned
//   0xXXX2 = 15087 (35.3%) strings, 5145 (34.1%) of which same-aligned
//   0xXXX4 = 525 (1.2%) strings, 0 (0.0%) of which same-aligned
//   0xXXX6 = 557 (1.3%) strings, 6 (1.1%) of which same-aligned
//   0xXXX8 = 509 (1.2%) strings, 0 (0.0%) of which same-aligned
//   0xXXXa = 24358 (57.0%) strings, 9901 (40.6%) of which same-aligned
//   0xXXXc = 557 (1.3%) strings, 0 (0.0%) of which same-aligned
//   0xXXXe = 601 (1.4%) strings, 15 (2.5%) of which same-aligned
//   total  = 42706 (100%) strings, 15067 (35.3%) of which same-aligned
//
// 92% of the strings have alignment of 2 or 10, which is due to malloc on
// 32-bit Linux returning values aligned to 8 bytes, and offsetof(array, QString::Data) == 18.
//
// The profile on 64-bit will be different since offsetof(array, QString::Data) == 26.
//
// The benchmark results were, for a Core-i7 @ 2.67 GHz 32-bit, compiled with -O3 -funroll-loops:
//   16-bit loads only:           872,301 CPU ticks [Qt 4.5 / memcmp]
//   32- and 16-bit loads:        773,362 CPU ticks [Qt 4.6]
//   SSE2 "movdqu" 128-bit loads: 618,736 CPU ticks
//   SSE3 "lddqu" 128-bit loads:  619,954 CPU ticks
//   SSSE3 "palignr" corrections: 852,147 CPU ticks
//   SSE4.2 "pcmpestrm":          738,702 CPU ticks
//
// The same benchmark on an Atom N450 @ 1.66 GHz, is:
//  16-bit loads only:            2,185,882 CPU ticks
//  32- and 16-bit loads:         1,805,060 CPU ticks
//  SSE2 "movdqu" 128-bit loads:  2,529,843 CPU ticks
//  SSE3 "lddqu" 128-bit loads:   2,514,858 CPU ticks
//  SSSE3 "palignr" corrections:  2,160,325 CPU ticks
//  SSE4.2 not available
//
// The conclusion we reach is that alignment the SSE2 unaligned code can gain
// 20% improvement in performance in some systems, but suffers a penalty due
// to the unaligned loads on others.

static bool qMemEquals(const quint16 *a, const quint16 *b, int length)
{
    if (a == b || !length)
        return true;

    register union {
        const quint16 *w;
        const quint32 *d;
        quintptr value;
    } sa, sb;
    sa.w = a;
    sb.w = b;

    // check alignment
    if ((sa.value & 2) == (sb.value & 2)) {
        // both addresses have the same alignment
        if (sa.value & 2) {
            // both addresses are not aligned to 4-bytes boundaries
            // compare the first character
            if (*sa.w != *sb.w)
                return false;
            --length;
            ++sa.w;
            ++sb.w;

            // now both addresses are 4-bytes aligned
        }

        // both addresses are 4-bytes aligned
        // do a fast 32-bit comparison
        register const quint32 *e = sa.d + (length >> 1);
        for ( ; sa.d != e; ++sa.d, ++sb.d) {
            if (*sa.d != *sb.d)
                return false;
        }

        // do we have a tail?
        return (length & 1) ? *sa.w == *sb.w : true;
    } else {
        // one of the addresses isn't 4-byte aligned but the other is
        register const quint16 *e = sa.w + length;
        for ( ; sa.w != e; ++sa.w, ++sb.w) {
            if (*sa.w != *sb.w)
                return false;
        }
    }
    return true;
}

/*!
    \internal

    Returns the index position of the first occurrence of the
    character \a ch in the string given by \a str and \a len,
    searching forward from index
    position \a from. Returns -1 if \a ch could not be found.
*/
static int findChar(const QChar *str, int len, QChar ch, int from,
    Qt::CaseSensitivity cs)
{
    const ushort *s = (const ushort *)str;
    ushort c = ch.unicode();
    if (from < 0)
        from = qMax(from + len, 0);
    if (from < len) {
        const ushort *n = s + from - 1;
        const ushort *e = s + len;
        if (cs == Qt::CaseSensitive) {
            while (++n != e)
                if (*n == c)
                    return  n - s;
        } else {
            c = foldCase(c);
            while (++n != e)
                if (foldCase(*n) == c)
                    return  n - s;
        }
    }
    return -1;
}

#define REHASH(a) \
    if (sl_minus_1 < (int)sizeof(int) * CHAR_BIT)       \
        hashHaystack -= (a) << sl_minus_1; \
    hashHaystack <<= 1

inline bool qIsUpper(char ch)
{
    return ch >= 'A' && ch <= 'Z';
}

inline bool qIsDigit(char ch)
{
    return ch >= '0' && ch <= '9';
}

inline char qToLower(char ch)
{
    if (ch >= 'A' && ch <= 'Z')
        return ch - 'A' + 'a';
    else
        return ch;
}

const QString::Null QString::null = { };

/*!
  \macro QT_NO_CAST_FROM_ASCII
  \relates QString

  Disables automatic conversions from 8-bit strings (char *) to unicode QStrings

  \sa QT_NO_CAST_TO_ASCII, QT_NO_CAST_FROM_BYTEARRAY
*/

/*!
  \macro QT_NO_CAST_TO_ASCII
  \relates QString

  disables automatic conversion from QString to 8-bit strings (char *)

  \sa QT_NO_CAST_FROM_ASCII, QT_NO_CAST_FROM_BYTEARRAY
*/

/*!
  \macro QT_ASCII_CAST_WARNINGS
  \internal
  \relates QString

  This macro can be defined to force a warning whenever a function is
  called that automatically converts between unicode and 8-bit encodings.

  Note: This only works for compilers that support warnings for
  deprecated API.

  \sa QT_NO_CAST_TO_ASCII, QT_NO_CAST_FROM_ASCII
*/

/*!
    \class QCharRef
    \reentrant
    \brief The QCharRef class is a helper class for QString.

    \internal

    \ingroup string-processing

    When you get an object of type QCharRef, if you can assign to it,
    the assignment will apply to the character in the string from
    which you got the reference. That is its whole purpose in life.
    The QCharRef becomes invalid once modifications are made to the
    string: if you want to keep the character, copy it into a QChar.

    Most of the QChar member functions also exist in QCharRef.
    However, they are not explicitly documented here.

    \sa QString::operator[]() QString::at() QChar
*/

/*!
    \class QString
    \reentrant

    \brief The QString class provides a Unicode character string.

    \ingroup tools
    \ingroup shared
    \ingroup string-processing

    QString stores a string of 16-bit \l{QChar}s, where each QChar
    corresponds one Unicode 4.0 character. (Unicode characters
    with code values above 65535 are stored using surrogate pairs,
    i.e., two consecutive \l{QChar}s.)

    \l{Unicode} is an international standard that supports most of the
    writing systems in use today. It is a superset of US-ASCII (ANSI
    X3.4-1986) and Latin-1 (ISO 8859-1), and all the US-ASCII/Latin-1
    characters are available at the same code positions.

    Behind the scenes, QString uses \l{implicit sharing}
    (copy-on-write) to reduce memory usage and to avoid the needless
    copying of data. This also helps reduce the inherent overhead of
    storing 16-bit characters instead of 8-bit characters.

    In addition to QString, Qt also provides the QByteArray class to
    store raw bytes and traditional 8-bit '\\0'-terminated strings.
    For most purposes, QString is the class you want to use. It is
    used throughout the Qt API, and the Unicode support ensures that
    your applications will be easy to translate if you want to expand
    your application's market at some point. The two main cases where
    QByteArray is appropriate are when you need to store raw binary
    data, and when memory conservation is critical (e.g., with
    \l{Qt for Embedded Linux}).

    \tableofcontents

    \section1 Initializing a String

    One way to initialize a QString is simply to pass a \c{const char
    *} to its constructor. For example, the following code creates a
    QString of size 5 containing the data "Hello":

    \snippet doc/src/snippets/qstring/main.cpp 0

    QString converts the \c{const char *} data into Unicode using the
    fromAscii() function. By default, fromAscii() treats character
    above 128 as Latin-1 characters, but this can be changed by
    calling QTextCodec::setCodecForCStrings().

    In all of the QString functions that take \c{const char *}
    parameters, the \c{const char *} is interpreted as a classic
    C-style '\\0'-terminated string. It is legal for the \c{const char
    *} parameter to be 0.

    You can also provide string data as an array of \l{QChar}s:

    \snippet doc/src/snippets/qstring/main.cpp 1

    QString makes a deep copy of the QChar data, so you can modify it
    later without experiencing side effects. (If for performance
    reasons you don't want to take a deep copy of the character data,
    use QString::fromRawData() instead.)

    Another approach is to set the size of the string using resize()
    and to initialize the data character per character. QString uses
    0-based indexes, just like C++ arrays. To access the character at
    a particular index position, you can use \l operator[](). On
    non-const strings, \l operator[]() returns a reference to a
    character that can be used on the left side of an assignment. For
    example:

    \snippet doc/src/snippets/qstring/main.cpp 2

    For read-only access, an alternative syntax is to use the at()
    function:

    \snippet doc/src/snippets/qstring/main.cpp 3

    The at() function can be faster than \l operator[](), because it
    never causes a \l{deep copy} to occur. Alternatively, use the
    left(), right(), or mid() functions to extract several characters
    at a time.

    A QString can embed '\\0' characters (QChar::Null). The size()
    function always returns the size of the whole string, including
    embedded '\\0' characters.

    After a call to the resize() function, newly allocated characters
    have undefined values. To set all the characters in the string to
    a particular value, use the fill() function.

    QString provides dozens of overloads designed to simplify string
    usage. For example, if you want to compare a QString with a string
    literal, you can write code like this and it will work as expected:

    \snippet doc/src/snippets/qstring/main.cpp 4

    You can also pass string literals to functions that take QStrings
    as arguments, invoking the QString(const char *)
    constructor. Similarly, you can pass a QString to a function that
    takes a \c{const char *} argument using the \l qPrintable() macro
    which returns the given QString as a \c{const char *}. This is
    equivalent to calling <QString>.toLocal8Bit().constData().

    \section1 Manipulating String Data

    QString provides the following basic functions for modifying the
    character data: append(), prepend(), insert(), replace(), and
    remove(). For example:

    \snippet doc/src/snippets/qstring/main.cpp 5

    If you are building a QString gradually and know in advance
    approximately how many characters the QString will contain, you
    can call reserve(), asking QString to preallocate a certain amount
    of memory. You can also call capacity() to find out how much
    memory QString actually allocated.

    The replace() and remove() functions' first two arguments are the
    position from which to start erasing and the number of characters
    that should be erased.  If you want to replace all occurrences of
    a particular substring with another, use one of the two-parameter
    replace() overloads.

    A frequent requirement is to remove whitespace characters from a
    string ('\\n', '\\t', ' ', etc.). If you want to remove whitespace
    from both ends of a QString, use the trimmed() function. If you
    want to remove whitespace from both ends and replace multiple
    consecutive whitespaces with a single space character within the
    string, use simplified().

    If you want to find all occurrences of a particular character or
    substring in a QString, use the indexOf() or lastIndexOf()
    functions. The former searches forward starting from a given index
    position, the latter searches backward. Both return the index
    position of the character or substring if they find it; otherwise,
    they return -1.  For example, here's a typical loop that finds all
    occurrences of a particular substring:

    \snippet doc/src/snippets/qstring/main.cpp 6

    QString provides many functions for converting numbers into
    strings and strings into numbers. See the arg() functions, the
    setNum() functions, the number() static functions, and the
    toInt(), toDouble(), and similar functions.

    To get an upper- or lowercase version of a string use toUpper() or
    toLower().

    Lists of strings are handled by the QStringList class. You can
    split a string into a list of strings using the split() function,
    and join a list of strings into a single string with an optional
    separator using QStringList::join(). You can obtain a list of
    strings from a string list that contain a particular substring or
    that match a particular QRegExp using the QStringList::filter()
    function.

    \section1 Querying String Data

    If you want to see if a QString starts or ends with a particular
    substring use startsWith() or endsWith(). If you simply want to
    check whether a QString contains a particular character or
    substring, use the contains() function. If you want to find out
    how many times a particular character or substring occurs in the
    string, use count().

    QStrings can be compared using overloaded operators such as \l
    operator<(), \l operator<=(), \l operator==(), \l operator>=(),
    and so on.  Note that the comparison is based exclusively on the
    numeric Unicode values of the characters. It is very fast, but is
    not what a human would expect; the QString::localeAwareCompare()
    function is a better choice for sorting user-interface strings.

    To obtain a pointer to the actual character data, call data() or
    constData(). These functions return a pointer to the beginning of
    the QChar data. The pointer is guaranteed to remain valid until a
    non-const function is called on the QString.

    \section1 Converting Between 8-Bit Strings and Unicode Strings

    QString provides the following four functions that return a
    \c{const char *} version of the string as QByteArray: toAscii(),
    toLatin1(), toUtf8(), and toLocal8Bit().

    \list
    \o toAscii() returns an 8-bit string encoded using the codec
       specified by QTextCodec::codecForCStrings (by default, that is
       Latin 1).
    \o toLatin1() returns a Latin-1 (ISO 8859-1) encoded 8-bit string.
    \o toUtf8() returns a UTF-8 encoded 8-bit string. UTF-8 is a
       superset of US-ASCII (ANSI X3.4-1986) that supports the entire
       Unicode character set through multibyte sequences.
    \o toLocal8Bit() returns an 8-bit string using the system's local
       encoding.
    \endlist

    To convert from one of these encodings, QString provides
    fromAscii(), fromLatin1(), fromUtf8(), and fromLocal8Bit(). Other
    encodings are supported through the QTextCodec class.

    As mentioned above, QString provides a lot of functions and
    operators that make it easy to interoperate with \c{const char *}
    strings. But this functionality is a double-edged sword: It makes
    QString more convenient to use if all strings are US-ASCII or
    Latin-1, but there is always the risk that an implicit conversion
    from or to \c{const char *} is done using the wrong 8-bit
    encoding. To minimize these risks, you can turn off these implicit
    conversions by defining the following two preprocessor symbols:

    \list
    \o \c QT_NO_CAST_FROM_ASCII disables automatic conversions from
       C string literals and pointers to Unicode.
    \o \c QT_NO_CAST_TO_ASCII disables automatic conversion from QString
       to C strings.
    \endlist

    One way to define these preprocessor symbols globally for your
    application is to add the following entry to your
    \l{qmake Project Files}{qmake project file}:

    \snippet doc/src/snippets/code/src_corelib_tools_qstring.cpp 0

    You then need to explicitly call fromAscii(), fromLatin1(),
    fromUtf8(), or fromLocal8Bit() to construct a QString from an
    8-bit string, or use the lightweight QLatin1String class, for
    example:

    \snippet doc/src/snippets/code/src_corelib_tools_qstring.cpp 1

    Similarly, you must call toAscii(), toLatin1(), toUtf8(), or
    toLocal8Bit() explicitly to convert the QString to an 8-bit
    string.  (Other encodings are supported through the QTextCodec
    class.)

    \table 100 %
    \header
    \o Note for C Programmers

    \row
    \o
    Due to C++'s type system and the fact that QString is
    \l{implicitly shared}, QStrings may be treated like \c{int}s or
    other basic types. For example:

    \snippet doc/src/snippets/qstring/main.cpp 7

    The \c result variable, is a normal variable allocated on the
    stack. When \c return is called, and because we're returning by
    value, the copy constructor is called and a copy of the string is
    returned. No actual copying takes place thanks to the implicit
    sharing.

    \endtable

    \section1 Distinction Between Null and Empty Strings

    For historical reasons, QString distinguishes between a null
    string and an empty string. A \e null string is a string that is
    initialized using QString's default constructor or by passing
    (const char *)0 to the constructor. An \e empty string is any
    string with size 0. A null string is always empty, but an empty
    string isn't necessarily null:

    \snippet doc/src/snippets/qstring/main.cpp 8

    All functions except isNull() treat null strings the same as empty
    strings. For example, toAscii().constData() returns a pointer to a
    '\\0' character for a null string (\e not a null pointer), and
    QString() compares equal to QString(""). We recommend that you
    always use the isEmpty() function and avoid isNull().

    \section1 Argument Formats

    In member functions where an argument \e format can be specified
    (e.g., arg(), number()), the argument \e format can be one of the
    following:

    \table
    \header \o Format \o Meaning
    \row \o \c e \o format as [-]9.9e[+|-]999
    \row \o \c E \o format as [-]9.9E[+|-]999
    \row \o \c f \o format as [-]9.9
    \row \o \c g \o use \c e or \c f format, whichever is the most concise
    \row \o \c G \o use \c E or \c f format, whichever is the most concise
    \endtable

    A \e precision is also specified with the argument \e format. For
    the 'e', 'E', and 'f' formats, the \e precision represents the
    number of digits \e after the decimal point. For the 'g' and 'G'
    formats, the \e precision represents the maximum number of
    significant digits (trailing zeroes are omitted).

    \section1 More Efficient String Construction

    Using the QString \c{'+'} operator, it is easy to construct a
    complex string from multiple substrings. You will often write code
    like this:

    \snippet doc/src/snippets/qstring/stringbuilder.cpp 0

    There is nothing wrong with either of these string constructions,
    but there are a few hidden inefficiencies. Beginning with Qt 4.6,
    you can eliminate them.

    First, multiple uses of the \c{'+'} operator usually means
    multiple memory allocations. When concatenating \e{n} substrings,
    where \e{n > 2}, there can be as many as \e{n - 1} calls to the
    memory allocator.

    Second, QLatin1String does not store its length internally but
    calls qstrlen() when it needs to know its length.

    In 4.6, an internal template class \c{QStringBuilder} has been
    added along with a few helper functions. This class is marked
    internal and does not appear in the documentation, because you
    aren't meant to instantiate it in your code. Its use will be
    automatic, as described below. The class is found in
    \c {src/corelib/tools/qstringbuilder.cpp} if you want to have a
    look at it.

    \c{QStringBuilder} uses expression templates and reimplements the
    \c{'%'} operator so that when you use \c{'%'} for string
    concatenation instead of \c{'+'}, multiple substring
    concatenations will be postponed until the final result is about
    to be assigned to a QString. At this point, the amount of memory
    required for the final result is known. The memory allocator is
    then called \e{once} to get the required space, and the substrings
    are copied into it one by one.

    \c{QLatin1Literal} is a second internal class that can replace
    QLatin1String, which can't be changed for compatibility reasons.
    \c{QLatin1Literal} stores its length, thereby saving time when
    \c{QStringBuilder} computes the amount of memory required for the
    final string.

    Additional efficiency is gained by inlining and reduced reference
    counting (the QString created from a \c{QStringBuilder} typically
    has a ref count of 1, whereas QString::append() needs an extra
    test).

    There are three ways you can access this improved method of string
    construction. The straightforward way is to include
    \c{QStringBuilder} wherever you want to use it, and use the
    \c{'%'} operator instead of \c{'+'} when concatenating strings:

    \snippet doc/src/snippets/qstring/stringbuilder.cpp 5

    A more global approach which is the most convenient but
    not entirely source compatible, is to this define in your
    .pro file:

    \snippet doc/src/snippets/qstring/stringbuilder.cpp 3

    and the \c{'+'} will automatically be performed as the
    \c{QStringBuilder} \c{'%'} everywhere.

    \sa fromRawData(), QChar, QLatin1String, QByteArray, QStringRef
*/

/*!
    \enum QString::SplitBehavior

    This enum specifies how the split() function should behave with
    respect to empty strings.

    \value KeepEmptyParts  If a field is empty, keep it in the result.
    \value SkipEmptyParts  If a field is empty, don't include it in the result.

    \sa split()
*/

QString::Data QString::shared_null = { Q_BASIC_ATOMIC_INITIALIZER(1),
                                       0, 0, shared_null.array, 0, 0, 0, 0, 0, 0, {0} };
QString::Data QString::shared_empty = { Q_BASIC_ATOMIC_INITIALIZER(1),
                                        0, 0, shared_empty.array, 0, 0, 0, 0, 0, 0, {0} };

int QString::grow(int size)
{
    return qAllocMore(size * sizeof(QChar), sizeof(Data)) / sizeof(QChar);
}

/*! \typedef QString::ConstIterator

    Qt-style synonym for QString::const_iterator.
*/

/*! \typedef QString::Iterator

    Qt-style synonym for QString::iterator.
*/

/*! \typedef QString::const_iterator

    The QString::const_iterator typedef provides an STL-style const
    iterator for QString.

    \sa QString::iterator
*/

/*! \typedef QString::iterator

    The QString::iterator typedef provides an STL-style non-const
    iterator for QString.

    \sa QString::const_iterator
*/

/*!
    \typedef QString::const_reference
    \since 4.8

    The QString::const_reference typedef provides an STL-style
    const reference for QString.
*/
/*!
    \typedef QString::reference
    \since 4.8

    The QString::const_reference typedef provides an STL-style
    reference for QString.
*/
/*!
    \typedef QString::value_type
    \since 4.8

    The QString::const_reference typedef provides an STL-style
    value type for QString.
*/

/*! \fn QString::iterator QString::begin()

    Returns an \l{STL-style iterator} pointing to the first character in
    the string.

    \sa constBegin(), end()
*/

/*! \fn QString::const_iterator QString::begin() const

    \overload begin()
*/

/*! \fn QString::const_iterator QString::constBegin() const

    Returns a const \l{STL-style iterator} pointing to the first character
    in the string.

    \sa begin(), constEnd()
*/

/*! \fn QString::iterator QString::end()

    Returns an \l{STL-style iterator} pointing to the imaginary character
    after the last character in the string.

    \sa begin(), constEnd()
*/

/*! \fn QString::const_iterator QString::end() const

    \overload end()
*/

/*! \fn QString::const_iterator QString::constEnd() const

    Returns a const \l{STL-style iterator} pointing to the imaginary
    item after the last item in the list.

    \sa constBegin(), end()
*/

/*!
    \fn QString::QString()

    Constructs a null string. Null strings are also empty.

    \sa isEmpty()
*/

/*! \fn QString::QString(const char *str)

    Constructs a string initialized with the 8-bit string \a str. The
    given const char pointer is converted to Unicode using the
    fromAscii() function.

    You can disable this constructor by defining \c
    QT_NO_CAST_FROM_ASCII when you compile your applications. This
    can be useful if you want to ensure that all user-visible strings
    go through QObject::tr(), for example.

    \sa fromAscii(), fromLatin1(), fromLocal8Bit(), fromUtf8()
*/

/*! \fn QString QString::fromStdString(const std::string &str)

    Returns a copy of the \a str string. The given string is converted
    to Unicode using the fromAscii() function.

    This constructor is only available if Qt is configured with STL
    compatibility enabled.

    \sa  fromAscii(), fromLatin1(), fromLocal8Bit(), fromUtf8()
*/

/*! \fn QString QString::fromStdWString(const std::wstring &str)

    Returns a copy of the \a str string. The given string is assumed
    to be encoded in utf16 if the size of wchar_t is 2 bytes (e.g. on
    windows) and ucs4 if the size of wchar_t is 4 bytes (most Unix
    systems).

    This method is only available if Qt is configured with STL
    compatibility enabled.

    \sa fromUtf16(), fromLatin1(), fromLocal8Bit(), fromUtf8(), fromUcs4()
*/

/*!
    \since 4.2

    Returns a copy of the \a string, where the encoding of \a string depends on
    the size of wchar. If wchar is 4 bytes, the \a string is interpreted as ucs-4,
    if wchar is 2 bytes it is interpreted as ucs-2.

    If \a size is -1 (default), the \a string has to be 0 terminated.

    \sa fromUtf16(), fromLatin1(), fromLocal8Bit(), fromUtf8(), fromUcs4(), fromStdWString()
*/
QString QString::fromWCharArray(const wchar_t *string, int size)
{
    if (sizeof(wchar_t) == sizeof(QChar)) {
        return fromUtf16((const ushort *)string, size);
    } else {
        return fromUcs4((uint *)string, size);
    }
}

/*! \fn std::wstring QString::toStdWString() const

    Returns a std::wstring object with the data contained in this
    QString. The std::wstring is encoded in utf16 on platforms where
    wchar_t is 2 bytes wide (e.g. windows) and in ucs4 on platforms
    where wchar_t is 4 bytes wide (most Unix systems).

    This operator is mostly useful to pass a QString to a function
    that accepts a std::wstring object.

    This operator is only available if Qt is configured with STL
    compatibility enabled.

    \sa utf16(), toAscii(), toLatin1(), toUtf8(), toLocal8Bit()
*/

template<typename T> int toUcs4_helper(const unsigned short *uc, int length, T *out)
{
    int i = 0;
    for (; i < length; ++i) {
        uint u = uc[i];
        if (QChar::isHighSurrogate(u) && i < length-1) {
            ushort low = uc[i+1];
            if (QChar::isLowSurrogate(low)) {
                ++i;
                u = QChar::surrogateToUcs4(u, low);
            }
        }
        *out = T(u);
        ++out;
    }
    return i;
}

/*!
  \since 4.2

  Fills the \a array with the data contained in this QString object.
  The array is encoded in utf16 on platforms where
  wchar_t is 2 bytes wide (e.g. windows) and in ucs4 on platforms
  where wchar_t is 4 bytes wide (most Unix systems).

  \a array has to be allocated by the caller and contain enough space to
  hold the complete string (allocating the array with the same length as the
  string is always sufficient).

  returns the actual length of the string in \a array.

  \note This function does not append a null character to the array.

  \sa utf16(), toUcs4(), toAscii(), toLatin1(), toUtf8(), toLocal8Bit(), toStdWString()
*/
int QString::toWCharArray(wchar_t *array) const
{
    if (sizeof(wchar_t) == sizeof(QChar)) {
        memcpy(array, utf16(), sizeof(wchar_t)*length());
        return length();
    } else {
        return toUcs4_helper<wchar_t>(utf16(), length(), array);
    }
}

/*! \fn QString::QString(const QString &other)

    Constructs a copy of \a other.

    This operation takes \l{constant time}, because QString is
    \l{implicitly shared}. This makes returning a QString from a
    function very fast. If a shared instance is modified, it will be
    copied (copy-on-write), and that takes \l{linear time}.

    \sa operator=()
*/

/*!
    Constructs a string initialized with the first \a size characters
    of the QChar array \a unicode.

    QString makes a deep copy of the string data. The unicode data is copied as
    is and the Byte Order Mark is preserved if present.
*/
QString::QString(const QChar *unicode, int size)
{
   if (!unicode) {
        d = &shared_null;
        d->ref.ref();
    } else if (size <= 0) {
        d = &shared_empty;
        d->ref.ref();
    } else {
        d = (Data*) qMalloc(sizeof(Data)+size*sizeof(QChar));
        Q_CHECK_PTR(d);
        d->ref = 1;
        d->alloc = d->size = size;
        d->clean = d->asciiCache = d->simpletext = d->righttoleft = d->capacity = 0;
        d->data = d->array;
        memcpy(d->array, unicode, size * sizeof(QChar));
        d->array[size] = '\0';
    }
}

/*!
    \since 4.7

    Constructs a string initialized with the characters of the QChar array
    \a unicode, which must be terminated with a 0.

    QString makes a deep copy of the string data. The unicode data is copied as
    is and the Byte Order Mark is preserved if present.
*/
QString::QString(const QChar *unicode)
{
     if (!unicode) {
         d = &shared_null;
         d->ref.ref();
     } else {
         int size = 0;
         while (unicode[size] != 0)
             ++size;
         if (!size) {
             d = &shared_empty;
             d->ref.ref();
         } else {
             d = (Data*) qMalloc(sizeof(Data)+size*sizeof(QChar));
             Q_CHECK_PTR(d);
             d->ref = 1;
             d->alloc = d->size = size;
             d->clean = d->asciiCache = d->simpletext = d->righttoleft = d->capacity = 0;
             d->data = d->array;
             memcpy(d->array, unicode, size * sizeof(QChar));
             d->array[size] = '\0';
         }
     }
}


/*!
    Constructs a string of the given \a size with every character set
    to \a ch.

    \sa fill()
*/
QString::QString(int size, QChar ch)
{
   if (size <= 0) {
        d = &shared_empty;
        d->ref.ref();
    } else {
        d = (Data*) qMalloc(sizeof(Data)+size*sizeof(QChar));
        Q_CHECK_PTR(d);
        d->ref = 1;
        d->alloc = d->size = size;
        d->clean = d->asciiCache = d->simpletext = d->righttoleft = d->capacity = 0;
        d->data = d->array;
        d->array[size] = '\0';
        ushort *i = d->array + size;
        ushort *b = d->array;
        const ushort value = ch.unicode();
        while (i != b)
           *--i = value;
    }
}

/*! \fn QString::QString(int size, Qt::Initialization)
  \internal

  Constructs a string of the given \a size without initializing the
  characters. This is only used in \c QStringBuilder::toString().
*/
QString::QString(int size, Qt::Initialization)
{
    d = (Data*) qMalloc(sizeof(Data)+size*sizeof(QChar));
    Q_CHECK_PTR(d);
    d->ref = 1;
    d->alloc = d->size = size;
    d->clean = d->asciiCache = d->simpletext = d->righttoleft = d->capacity = 0;
    d->data = d->array;
    d->array[size] = '\0';
}

/*! \fn QString::QString(const QLatin1String &str)

    Constructs a copy of the Latin-1 string \a str.

    \sa fromLatin1()
*/

/*!
    Constructs a string of size 1 containing the character \a ch.
*/
QString::QString(QChar ch)
{
    void *buf = qMalloc(sizeof(Data) + sizeof(QChar));
    Q_CHECK_PTR(buf);
    d = reinterpret_cast<Data *>(buf);
    d->ref = 1;
    d->alloc = d->size = 1;
    d->clean = d->asciiCache = d->simpletext = d->righttoleft = d->capacity = 0;
    d->data = d->array;
    d->array[0] = ch.unicode();
    d->array[1] = '\0';
}

/*! \fn QString::QString(const QByteArray &ba)

    Constructs a string initialized with the byte array \a ba. The
    given byte array is converted to Unicode using fromAscii(). Stops
    copying at the first 0 character, otherwise copies the entire byte
    array.

    You can disable this constructor by defining \c
    QT_NO_CAST_FROM_ASCII when you compile your applications. This
    can be useful if you want to ensure that all user-visible strings
    go through QObject::tr(), for example.

    \sa fromAscii(), fromLatin1(), fromLocal8Bit(), fromUtf8()
*/

/*! \fn QString::QString(const Null &)
    \internal
*/

/*! \fn QString &QString::operator=(const Null &)
    \internal
*/

/*!
  \fn QString::~QString()

    Destroys the string.
*/


/*! \fn void QString::swap(QString &other)
    \since 4.8

    Swaps string \a other with this string. This operation is very fast and
    never fails.
*/

/*! \fn void QString::detach()

    \internal
*/

/*! \fn bool QString::isDetached() const

    \internal
*/

/*! \fn bool QString::isSharedWith(const QString &other) const

    \internal
*/

// ### Qt 5: rename freeData() to avoid confusion. See task 197625.
void QString::free(Data *d)
{
#ifdef QT3_SUPPORT
    if (d->asciiCache) {
        Q_ASSERT(asciiCache);
        asciiCache->remove(d);
    }
#endif
    qFree(d);
}

/*!
    Sets the size of the string to \a size characters.

    If \a size is greater than the current size, the string is
    extended to make it \a size characters long with the extra
    characters added to the end. The new characters are uninitialized.

    If \a size is less than the current size, characters are removed
    from the end.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 45

    If you want to append a certain number of identical characters to
    the string, use \l operator+=() as follows rather than resize():

    \snippet doc/src/snippets/qstring/main.cpp 46

    If you want to expand the string so that it reaches a certain
    width and fill the new positions with a particular character, use
    the leftJustified() function:

    If \a size is negative, it is equivalent to passing zero.

    \snippet doc/src/snippets/qstring/main.cpp 47

    \sa truncate(), reserve()
*/

void QString::resize(int size)
{
    if (size < 0)
        size = 0;

    if (size == 0 && !d->capacity) {
        Data *x = &shared_empty;
        x->ref.ref();
        if (!d->ref.deref())
            QString::free(d);
        d = x;
    } else {
        if (d->ref != 1 || size > d->alloc ||
            (!d->capacity && size < d->size && size < d->alloc >> 1))
            realloc(grow(size));
        if (d->alloc >= size) {
            d->size = size;
            if (d->data == d->array) {
                d->array[size] = '\0';
            }
        }
    }
}

/*! \fn int QString::capacity() const

    Returns the maximum number of characters that can be stored in
    the string without forcing a reallocation.

    The sole purpose of this function is to provide a means of fine
    tuning QString's memory usage. In general, you will rarely ever
    need to call this function. If you want to know how many
    characters are in the string, call size().

    \sa reserve(), squeeze()
*/

/*!
    \fn void QString::reserve(int size)

    Attempts to allocate memory for at least \a size characters. If
    you know in advance how large the string will be, you can call
    this function, and if you resize the string often you are likely
    to get better performance. If \a size is an underestimate, the
    worst that will happen is that the QString will be a bit slower.

    The sole purpose of this function is to provide a means of fine
    tuning QString's memory usage. In general, you will rarely ever
    need to call this function. If you want to change the size of the
    string, call resize().

    This function is useful for code that needs to build up a long
    string and wants to avoid repeated reallocation. In this example,
    we want to add to the string until some condition is true, and
    we're fairly sure that size is large enough to make a call to
    reserve() worthwhile:

    \snippet doc/src/snippets/qstring/main.cpp 44

    \sa squeeze(), capacity()
*/

/*!
    \fn void QString::squeeze()

    Releases any memory not required to store the character data.

    The sole purpose of this function is to provide a means of fine
    tuning QString's memory usage. In general, you will rarely ever
    need to call this function.

    \sa reserve(), capacity()
*/

// ### Qt 5: rename reallocData() to avoid confusion. 197625
void QString::realloc(int alloc)
{
    if (d->ref != 1 || d->data != d->array) {
        Data *x = static_cast<Data *>(qMalloc(sizeof(Data) + alloc * sizeof(QChar)));
        Q_CHECK_PTR(x);
        x->size = qMin(alloc, d->size);
        ::memcpy(x->array, d->data, x->size * sizeof(QChar));
        x->array[x->size] = 0;
        x->asciiCache = 0;
        x->ref = 1;
        x->alloc = alloc;
        x->clean = d->clean;
        x->simpletext = d->simpletext;
        x->righttoleft = d->righttoleft;
        x->capacity = d->capacity;
        x->data = x->array;
        if (!d->ref.deref())
            QString::free(d);
        d = x;
    } else {
#ifdef QT3_SUPPORT
        if (d->asciiCache) {
            Q_ASSERT(asciiCache);
            asciiCache->remove(d);
        }
#endif
        Data *p = static_cast<Data *>(qRealloc(d, sizeof(Data) + alloc * sizeof(QChar)));
        Q_CHECK_PTR(p);
        d = p;
        d->alloc = alloc;
        d->data = d->array;
    }
}

void QString::realloc()
{
    realloc(d->size);
}

void QString::expand(int i)
{
    int sz = d->size;
    resize(qMax(i + 1, sz));
    if (d->size - 1 > sz) {
        ushort *n = d->data + d->size - 1;
        ushort *e = d->data + sz;
        while (n != e)
           * --n = ' ';
    }
}

/*! \fn void QString::clear()

    Clears the contents of the string and makes it empty.

    \sa resize(), isEmpty()
*/

/*! \fn QString &QString::operator=(const QString &other)

    Assigns \a other to this string and returns a reference to this
    string.
*/

QString &QString::operator=(const QString &other)
{
    other.d->ref.ref();
    if (!d->ref.deref())
        QString::free(d);
    d = other.d;
    return *this;
}


/*! \fn QString &QString::operator=(const QLatin1String &str)

    \overload operator=()

    Assigns the Latin-1 string \a str to this string.
*/

/*! \fn QString &QString::operator=(const QByteArray &ba)

    \overload operator=()

    Assigns \a ba to this string. The byte array is converted to Unicode
    using the fromAscii() function. This function stops conversion at the
    first NUL character found, or the end of the \a ba byte array.

    You can disable this operator by defining \c
    QT_NO_CAST_FROM_ASCII when you compile your applications. This
    can be useful if you want to ensure that all user-visible strings
    go through QObject::tr(), for example.
*/

/*! \fn QString &QString::operator=(const char *str)

    \overload operator=()

    Assigns \a str to this string. The const char pointer is converted
    to Unicode using the fromAscii() function.

    You can disable this operator by defining \c
    QT_NO_CAST_FROM_ASCII when you compile your applications. This
    can be useful if you want to ensure that all user-visible strings
    go through QObject::tr(), for example.
*/

/*! \fn QString &QString::operator=(char ch)

    \overload operator=()

    Assigns character \a ch to this string. The character is converted
    to Unicode using the fromAscii() function.

    You can disable this operator by defining \c
    QT_NO_CAST_FROM_ASCII when you compile your applications. This
    can be useful if you want to ensure that all user-visible strings
    go through QObject::tr(), for example.
*/

/*!
    \overload operator=()

    Sets the string to contain the single character \a ch.
*/
QString &QString::operator=(QChar ch)
{
    return operator=(QString(ch));
}

/*!
     \fn QString& QString::insert(int position, const QString &str)

    Inserts the string \a str at the given index \a position and
    returns a reference to this string.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 26

    If the given \a position is greater than size(), the array is
    first extended using resize().

    \sa append(), prepend(), replace(), remove()
*/


/*!
    \fn QString &QString::insert(int position, const QLatin1String &str)
    \overload insert()

    Inserts the Latin-1 string \a str at the given index \a position.
*/
QString &QString::insert(int i, const QLatin1String &str)
{
    const uchar *s = (const uchar *)str.latin1();
    if (i < 0 || !s || !(*s))
        return *this;

    int len = qstrlen(str.latin1());
    expand(qMax(d->size, i) + len - 1);

    ::memmove(d->data + i + len, d->data + i, (d->size - i - len) * sizeof(QChar));
    for (int j = 0; j < len; ++j)
        d->data[i + j] = s[j];
    return *this;
}

/*!
    \fn QString& QString::insert(int position, const QChar *unicode, int size)
    \overload insert()

    Inserts the first \a size characters of the QChar array \a unicode
    at the given index \a position in the string.
*/
QString& QString::insert(int i, const QChar *unicode, int size)
{
    if (i < 0 || size <= 0)
        return *this;

    const ushort *s = (const ushort *)unicode;
    if (s >= d->data && s < d->data + d->alloc) {
        // Part of me - take a copy
        ushort *tmp = static_cast<ushort *>(qMalloc(size * sizeof(QChar)));
        Q_CHECK_PTR(tmp);
        memcpy(tmp, s, size * sizeof(QChar));
        insert(i, reinterpret_cast<const QChar *>(tmp), size);
        qFree(tmp);
        return *this;
    }

    expand(qMax(d->size, i) + size - 1);

    ::memmove(d->data + i + size, d->data + i, (d->size - i - size) * sizeof(QChar));
    memcpy(d->data + i, s, size * sizeof(QChar));
    return *this;
}

/*!
    \fn QString& QString::insert(int position, QChar ch)
    \overload insert()

    Inserts \a ch at the given index \a position in the string.
*/

QString& QString::insert(int i, QChar ch)
{
    if (i < 0)
        i += d->size;
    if (i < 0)
        return *this;
    expand(qMax(i, d->size));
    ::memmove(d->data + i + 1, d->data + i, (d->size - i) * sizeof(QChar));
    d->data[i] = ch.unicode();
    return *this;
}

/*!
    Appends the string \a str onto the end of this string.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 9

    This is the same as using the insert() function:

    \snippet doc/src/snippets/qstring/main.cpp 10

    The append() function is typically very fast (\l{constant time}),
    because QString preallocates extra space at the end of the string
    data so it can grow without reallocating the entire string each
    time.

    \sa operator+=(), prepend(), insert()
*/
QString &QString::append(const QString &str)
{
    if (str.d != &shared_null) {
        if (d == &shared_null) {
            operator=(str);
        } else {
            if (d->ref != 1 || d->size + str.d->size > d->alloc)
                realloc(grow(d->size + str.d->size));
            memcpy(d->data + d->size, str.d->data, str.d->size * sizeof(QChar));
            d->size += str.d->size;
            d->data[d->size] = '\0';
        }
    }
    return *this;
}

/*!
  \overload append()

  Appends the Latin-1 string \a str to this string.
*/
QString &QString::append(const QLatin1String &str)
{
    const uchar *s = (const uchar *)str.latin1();
    if (s) {
        int len = qstrlen((char *)s);
        if (d->ref != 1 || d->size + len > d->alloc)
            realloc(grow(d->size + len));
        ushort *i = d->data + d->size;
        while ((*i++ = *s++))
            ;
        d->size += len;
    }
    return *this;
}

/*! \fn QString &QString::append(const QByteArray &ba)

    \overload append()

    Appends the byte array \a ba to this string. The given byte array
    is converted to Unicode using the fromAscii() function.

    You can disable this function by defining \c QT_NO_CAST_FROM_ASCII
    when you compile your applications. This can be useful if you want
    to ensure that all user-visible strings go through QObject::tr(),
    for example.
*/

/*! \fn QString &QString::append(const char *str)

    \overload append()

    Appends the string \a str to this string. The given const char
    pointer is converted to Unicode using the fromAscii() function.

    You can disable this function by defining \c QT_NO_CAST_FROM_ASCII
    when you compile your applications. This can be useful if you want
    to ensure that all user-visible strings go through QObject::tr(),
    for example.
*/

/*!
    \overload append()

    Appends the character \a ch to this string.
*/
QString &QString::append(QChar ch)
{
    if (d->ref != 1 || d->size + 1 > d->alloc)
        realloc(grow(d->size + 1));
    d->data[d->size++] = ch.unicode();
    d->data[d->size] = '\0';
    return *this;
}

/*! \fn QString &QString::prepend(const QString &str)

    Prepends the string \a str to the beginning of this string and
    returns a reference to this string.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 36

    \sa append(), insert()
*/

/*! \fn QString &QString::prepend(const QLatin1String &str)

    \overload prepend()

    Prepends the Latin-1 string \a str to this string.
*/

/*! \fn QString &QString::prepend(const QByteArray &ba)

    \overload prepend()

    Prepends the byte array \a ba to this string. The byte array is
    converted to Unicode using the fromAscii() function.

    You can disable this function by defining \c
    QT_NO_CAST_FROM_ASCII when you compile your applications. This
    can be useful if you want to ensure that all user-visible strings
    go through QObject::tr(), for example.
*/

/*! \fn QString &QString::prepend(const char *str)

    \overload prepend()

    Prepends the string \a str to this string. The const char pointer
    is converted to Unicode using the fromAscii() function.

    You can disable this function by defining \c
    QT_NO_CAST_FROM_ASCII when you compile your applications. This
    can be useful if you want to ensure that all user-visible strings
    go through QObject::tr(), for example.
*/

/*! \fn QString &QString::prepend(QChar ch)

    \overload prepend()

    Prepends the character \a ch to this string.
*/

/*!
  \fn QString &QString::remove(int position, int n)

  Removes \a n characters from the string, starting at the given \a
  position index, and returns a reference to the string.

  If the specified \a position index is within the string, but \a
  position + \a n is beyond the end of the string, the string is
  truncated at the specified \a position.

  \snippet doc/src/snippets/qstring/main.cpp 37

  \sa insert(), replace()
*/
QString &QString::remove(int pos, int len)
{
    if (pos < 0)  // count from end of string
        pos += d->size;
    if (pos < 0 || pos >= d->size) {
        // range problems
    } else if (len >= d->size - pos) {
        resize(pos); // truncate
    } else if (len > 0) {
        detach();
        memmove(d->data + pos, d->data + pos + len,
                (d->size - pos - len + 1) * sizeof(ushort));
        d->size -= len;
    }
    return *this;
}

/*!
  Removes every occurrence of the given \a str string in this
  string, and returns a reference to this string.

  If \a cs is Qt::CaseSensitive (default), the search is
  case sensitive; otherwise the search is case insensitive.

  This is the same as \c replace(str, "", cs).

  \sa replace()
*/
QString &QString::remove(const QString &str, Qt::CaseSensitivity cs)
{
    if (str.d->size) {
        int i = 0;
        while ((i = indexOf(str, i, cs)) != -1)
            remove(i, str.d->size);
    }
    return *this;
}

/*!
  Removes every occurrence of the character \a ch in this string, and
  returns a reference to this string.

  If \a cs is Qt::CaseSensitive (default), the search is case
  sensitive; otherwise the search is case insensitive.

  Example:

  \snippet doc/src/snippets/qstring/main.cpp 38

  This is the same as \c replace(ch, "", cs).

  \sa replace()
*/
QString &QString::remove(QChar ch, Qt::CaseSensitivity cs)
{
    int i = 0;
    ushort c = ch.unicode();
    if (cs == Qt::CaseSensitive) {
        while (i < d->size)
            if (d->data[i] == ch)
                remove(i, 1);
            else
                i++;
    } else {
        c = foldCase(c);
        while (i < d->size)
            if (foldCase(d->data[i]) == c)
                remove(i, 1);
            else
                i++;
    }
    return *this;
}

/*!
  \fn QString &QString::remove(const QRegExp &rx)

  Removes every occurrence of the regular expression \a rx in the
  string, and returns a reference to the string. For example:

  \snippet doc/src/snippets/qstring/main.cpp 39

  \sa indexOf(), lastIndexOf(), replace()
*/

/*!
  \fn QString &QString::replace(int position, int n, const QString &after)

  Replaces \a n characters beginning at index \a position with
  the string \a after and returns a reference to this string.

  Example:

  \snippet doc/src/snippets/qstring/main.cpp 40

  \sa insert(), remove()
*/
QString &QString::replace(int pos, int len, const QString &after)
{
    QString copy = after;
    return replace(pos, len, copy.constData(), copy.length());
}

/*!
  \fn QString &QString::replace(int position, int n, const QChar *unicode, int size)
  \overload replace()
  Replaces \a n characters beginning at index \a position with the
  first \a size characters of the QChar array \a unicode and returns a
  reference to this string.
*/
QString &QString::replace(int pos, int len, const QChar *unicode, int size)
{
    if (pos < 0 || pos > d->size)
        return *this;
    if (pos + len > d->size)
        len = d->size - pos;

    uint index = pos;
    replace_helper(&index, 1, len, unicode, size);
    return *this;
}

/*!
  \fn QString &QString::replace(int position, int n, QChar after)
  \overload replace()

  Replaces \a n characters beginning at index \a position with the
  character \a after and returns a reference to this string.
*/
QString &QString::replace(int pos, int len, QChar after)
{
    return replace(pos, len, &after, 1);
}

/*!
  \overload replace()
  Replaces every occurrence of the string \a before with the string \a
  after and returns a reference to this string.

  If \a cs is Qt::CaseSensitive (default), the search is case
  sensitive; otherwise the search is case insensitive.

  Example:

  \snippet doc/src/snippets/qstring/main.cpp 41

  \note The replacement text is not rescanned after it is inserted.

  Example:

  \snippet doc/src/snippets/qstring/main.cpp 86
*/
QString &QString::replace(const QString &before, const QString &after, Qt::CaseSensitivity cs)
{
    return replace(before.constData(), before.size(), after.constData(), after.size(), cs);
}

/*!
  \internal
 */
void QString::replace_helper(uint *indices, int nIndices, int blen, const QChar *after, int alen)
{
    // copy *after in case it lies inside our own d->data area
    // (which we could possibly invalidate via a realloc or corrupt via memcpy operations.)
    QChar *afterBuffer = const_cast<QChar *>(after);
    if (after >= reinterpret_cast<QChar *>(d->data) && after < reinterpret_cast<QChar *>(d->data) + d->size) {
        afterBuffer = static_cast<QChar *>(qMalloc(alen*sizeof(QChar)));
        Q_CHECK_PTR(afterBuffer);
        ::memcpy(afterBuffer, after, alen*sizeof(QChar));
    }

    QT_TRY {
        if (blen == alen) {
            // replace in place
            detach();
            for (int i = 0; i < nIndices; ++i)
                memcpy(d->data + indices[i], afterBuffer, alen * sizeof(QChar));
        } else if (alen < blen) {
            // replace from front
            detach();
            uint to = indices[0];
            if (alen)
                memcpy(d->data+to, after, alen*sizeof(QChar));
            to += alen;
            uint movestart = indices[0] + blen;
            for (int i = 1; i < nIndices; ++i) {
                int msize = indices[i] - movestart;
                if (msize > 0) {
                    memmove(d->data + to, d->data + movestart, msize * sizeof(QChar));
                    to += msize;
                }
                if (alen) {
                    memcpy(d->data + to, afterBuffer, alen*sizeof(QChar));
                    to += alen;
                }
                movestart = indices[i] + blen;
            }
            int msize = d->size - movestart;
            if (msize > 0)
                memmove(d->data + to, d->data + movestart, msize * sizeof(QChar));
            resize(d->size - nIndices*(blen-alen));
        } else {
            // replace from back
            int adjust = nIndices*(alen-blen);
            int newLen = d->size + adjust;
            int moveend = d->size;
            resize(newLen);

            while (nIndices) {
                --nIndices;
                int movestart = indices[nIndices] + blen;
                int insertstart = indices[nIndices] + nIndices*(alen-blen);
                int moveto = insertstart + alen;
                memmove(d->data + moveto, d->data + movestart,
                        (moveend - movestart)*sizeof(QChar));
                memcpy(d->data + insertstart, afterBuffer, alen*sizeof(QChar));
                moveend = movestart-blen;
            }
        }
    } QT_CATCH(const std::bad_alloc &) {
        if (afterBuffer != after)
            qFree(afterBuffer);
        QT_RETHROW;
    }
    if (afterBuffer != after)
        qFree(afterBuffer);
}

/*!
  \since 4.5
  \overload replace()

  Replaces each occurrence in this string of the first \a blen
  characters of \a before with the first \a alen characters of \a
  after and returns a reference to this string.

  If \a cs is Qt::CaseSensitive (default), the search is case
  sensitive; otherwise the search is case insensitive.
*/
QString &QString::replace(const QChar *before, int blen,
                          const QChar *after, int alen,
                          Qt::CaseSensitivity cs)
{
    if (d->size == 0) {
        if (blen)
            return *this;
    } else {
        if (cs == Qt::CaseSensitive && before == after && blen == alen)
            return *this;
    }
    if (alen == 0 && blen == 0)
        return *this;

    QStringMatcher matcher(before, blen, cs);

    int index = 0;
    while (1) {
        uint indices[1024];
        uint pos = 0;
        while (pos < 1023) {
            index = matcher.indexIn(*this, index);
            if (index == -1)
                break;
            indices[pos++] = index;
            index += blen;
            // avoid infinite loop
            if (!blen)
                index++;
        }
        if (!pos)
            break;

        replace_helper(indices, pos, blen, after, alen);

        if (index == -1)
            break;
        // index has to be adjusted in case we get back into the loop above.
        index += pos*(alen-blen);
    }

    return *this;
}

/*!
  \overload replace()
  Replaces every occurrence of the character \a ch in the string with
  \a after and returns a reference to this string.

  If \a cs is Qt::CaseSensitive (default), the search is case
  sensitive; otherwise the search is case insensitive.
*/
QString& QString::replace(QChar ch, const QString &after, Qt::CaseSensitivity cs)
{
    if (after.d->size == 0)
        return remove(ch, cs);

    if (after.d->size == 1)
        return replace(ch, after.d->data[0], cs);

    if (d->size == 0)
        return *this;

    ushort cc = (cs == Qt::CaseSensitive ? ch.unicode() : ch.toCaseFolded().unicode());

    int index = 0;
    while (1) {
        uint indices[1024];
        uint pos = 0;
        if (cs == Qt::CaseSensitive) {
            while (pos < 1023 && index < d->size) {
                if (d->data[index] == cc)
                    indices[pos++] = index;
                index++;
            }
        } else {
            while (pos < 1023 && index < d->size) {
                if (QChar::toCaseFolded(d->data[index]) == cc)
                    indices[pos++] = index;
                index++;
            }
        }
        if (!pos)
            break;

        replace_helper(indices, pos, 1, after.constData(), after.d->size);

        if (index == -1)
            break;
        // index has to be adjusted in case we get back into the loop above.
        index += pos*(after.d->size - 1);
    }
    return *this;
}

/*!
  \overload replace()
  Replaces every occurrence of the character \a before with the
  character \a after and returns a reference to this string.

  If \a cs is Qt::CaseSensitive (default), the search is case
  sensitive; otherwise the search is case insensitive.
*/
QString& QString::replace(QChar before, QChar after, Qt::CaseSensitivity cs)
{
    ushort a = after.unicode();
    ushort b = before.unicode();
    if (d->size) {
        detach();
        ushort *i = d->data;
        const ushort *e = i + d->size;
        if (cs == Qt::CaseSensitive) {
            for (; i != e; ++i)
                if (*i == b)
                    *i = a;
        } else {
            b = foldCase(b);
            for (; i != e; ++i)
                if (foldCase(*i) == b)
                    *i = a;
        }
    }
    return *this;
}

/*!
  \since 4.5
  \overload replace()

  Replaces every occurrence of the string \a before with the string \a
  after and returns a reference to this string.

  If \a cs is Qt::CaseSensitive (default), the search is case
  sensitive; otherwise the search is case insensitive.

  \note The text is not rescanned after a replacement.
*/
QString &QString::replace(const QLatin1String &before,
                          const QLatin1String &after,
                          Qt::CaseSensitivity cs)
{
    int alen = qstrlen(after.latin1());
    QVarLengthArray<ushort> a(alen);
    for (int i = 0; i < alen; ++i)
        a[i] = (uchar)after.latin1()[i];
    int blen = qstrlen(before.latin1());
    QVarLengthArray<ushort> b(blen);
    for (int i = 0; i < blen; ++i)
        b[i] = (uchar)before.latin1()[i];
    return replace((const QChar *)b.data(), blen, (const QChar *)a.data(), alen, cs);
}

/*!
  \since 4.5
  \overload replace()

  Replaces every occurrence of the string \a before with the string \a
  after and returns a reference to this string.

  If \a cs is Qt::CaseSensitive (default), the search is case
  sensitive; otherwise the search is case insensitive.

  \note The text is not rescanned after a replacement.
*/
QString &QString::replace(const QLatin1String &before,
                          const QString &after,
                          Qt::CaseSensitivity cs)
{
    int blen = qstrlen(before.latin1());
    QVarLengthArray<ushort> b(blen);
    for (int i = 0; i < blen; ++i)
        b[i] = (uchar)before.latin1()[i];
    return replace((const QChar *)b.data(), blen, after.constData(), after.d->size, cs);
}

/*!
  \since 4.5
  \overload replace()

  Replaces every occurrence of the string \a before with the string \a
  after and returns a reference to this string.

  If \a cs is Qt::CaseSensitive (default), the search is case
  sensitive; otherwise the search is case insensitive.

  \note The text is not rescanned after a replacement.
*/
QString &QString::replace(const QString &before,
                          const QLatin1String &after,
                          Qt::CaseSensitivity cs)
{
    int alen = qstrlen(after.latin1());
    QVarLengthArray<ushort> a(alen);
    for (int i = 0; i < alen; ++i)
        a[i] = (uchar)after.latin1()[i];
    return replace(before.constData(), before.d->size, (const QChar *)a.data(), alen, cs);
}

/*!
  \since 4.5
  \overload replace()

  Replaces every occurrence of the character \a c with the string \a
  after and returns a reference to this string.

  If \a cs is Qt::CaseSensitive (default), the search is case
  sensitive; otherwise the search is case insensitive.

  \note The text is not rescanned after a replacement.
*/
QString &QString::replace(QChar c, const QLatin1String &after, Qt::CaseSensitivity cs)
{
    int alen = qstrlen(after.latin1());
    QVarLengthArray<ushort> a(alen);
    for (int i = 0; i < alen; ++i)
        a[i] = (uchar)after.latin1()[i];
    return replace(&c, 1, (const QChar *)a.data(), alen, cs);
}


/*!
  Returns true if string \a other is equal to this string; otherwise
  returns false.

  The comparison is based exclusively on the numeric Unicode values of
  the characters and is very fast, but is not what a human would
  expect. Consider sorting user-interface strings with
  localeAwareCompare().
*/
bool QString::operator==(const QString &other) const
{
    if (d->size != other.d->size)
        return false;

    return qMemEquals(d->data, other.d->data, d->size);
}

/*!
    \overload operator==()
*/
bool QString::operator==(const QLatin1String &other) const
{
    const ushort *uc = d->data;
    const ushort *e = uc + d->size;
    const uchar *c = (uchar *)other.latin1();

    if (!c)
        return isEmpty();

    while (*c) {
        if (uc == e || *uc != *c)
            return false;
        ++uc;
        ++c;
    }
    return (uc == e);
}

/*! \fn bool QString::operator==(const QByteArray &other) const

    \overload operator==()

    The \a other byte array is converted to a QString using the
    fromAscii() function. This function stops conversion at the
    first NUL character found, or the end of the byte array.

    You can disable this operator by defining \c
    QT_NO_CAST_FROM_ASCII when you compile your applications. This
    can be useful if you want to ensure that all user-visible strings
    go through QObject::tr(), for example.
*/

/*! \fn bool QString::operator==(const char *other) const

    \overload operator==()

    The \a other const char pointer is converted to a QString using
    the fromAscii() function.

    You can disable this operator by defining \c
    QT_NO_CAST_FROM_ASCII when you compile your applications. This
    can be useful if you want to ensure that all user-visible strings
    go through QObject::tr(), for example.
*/

/*!
    Returns true if this string is lexically less than string \a
    other; otherwise returns false.

    The comparison is based exclusively on the numeric Unicode values
    of the characters and is very fast, but is not what a human would
    expect. Consider sorting user-interface strings using the
    QString::localeAwareCompare() function.
*/
bool QString::operator<(const QString &other) const
{
    return ucstrcmp(constData(), length(), other.constData(), other.length()) < 0;
}

/*!
    \overload operator<()
*/
bool QString::operator<(const QLatin1String &other) const
{
    const ushort *uc = d->data;
    const ushort *e = uc + d->size;
    const uchar *c = (uchar *) other.latin1();

    if (!c || *c == 0)
        return false;

    while (*c) {
        if (uc == e || *uc != *c)
            break;
        ++uc;
        ++c;
    }
    return (uc == e ? *c : *uc < *c);
}

/*! \fn bool QString::operator<(const QByteArray &other) const

    \overload operator<()

    The \a other byte array is converted to a QString using the
    fromAscii() function. If any NUL characters ('\0') are embedded
    in the byte array, they will be included in the transformation.

    You can disable this operator by defining \c
    QT_NO_CAST_FROM_ASCII when you compile your applications. This
    can be useful if you want to ensure that all user-visible strings
    go through QObject::tr(), for example.
*/

/*! \fn bool QString::operator<(const char *other) const

    \overload operator<()

    The \a other const char pointer is converted to a QString using
    the fromAscii() function.

    You can disable this operator by defining \c
    QT_NO_CAST_FROM_ASCII when you compile your applications. This
    can be useful if you want to ensure that all user-visible strings
    go through QObject::tr(), for example.
*/

/*! \fn bool QString::operator<=(const QString &other) const

    Returns true if this string is lexically less than or equal to
    string \a other; otherwise returns false.

    The comparison is based exclusively on the numeric Unicode values
    of the characters and is very fast, but is not what a human would
    expect. Consider sorting user-interface strings with
    localeAwareCompare().
*/

/*! \fn bool QString::operator<=(const QLatin1String &other) const

    \overload operator<=()
*/

/*! \fn bool QString::operator<=(const QByteArray &other) const

    \overload operator<=()

    The \a other byte array is converted to a QString using the
    fromAscii() function. If any NUL characters ('\0') are embedded
    in the byte array, they will be included in the transformation.

    You can disable this operator by defining \c
    QT_NO_CAST_FROM_ASCII when you compile your applications. This
    can be useful if you want to ensure that all user-visible strings
    go through QObject::tr(), for example.
*/

/*! \fn bool QString::operator<=(const char *other) const

    \overload operator<=()

    The \a other const char pointer is converted to a QString using
    the fromAscii() function.

    You can disable this operator by defining \c
    QT_NO_CAST_FROM_ASCII when you compile your applications. This
    can be useful if you want to ensure that all user-visible strings
    go through QObject::tr(), for example.
*/

/*! \fn bool QString::operator>(const QString &other) const

    Returns true if this string is lexically greater than string \a
    other; otherwise returns false.

    The comparison is based exclusively on the numeric Unicode values
    of the characters and is very fast, but is not what a human would
    expect. Consider sorting user-interface strings with
    localeAwareCompare().
*/

/*!
    \overload operator>()
*/
bool QString::operator>(const QLatin1String &other) const
{
    const ushort *uc = d->data;;
    const ushort *e = uc + d->size;
    const uchar *c = (uchar *) other.latin1();

    if (!c || *c == '\0')
        return !isEmpty();

    while (*c) {
        if (uc == e || *uc != *c)
            break;
        ++uc;
        ++c;
    }
    return (uc == e ? false : *uc > *c);
}

/*! \fn bool QString::operator>(const QByteArray &other) const

    \overload operator>()

    The \a other byte array is converted to a QString using the
    fromAscii() function. If any NUL characters ('\0') are embedded
    in the byte array, they will be included in the transformation.

    You can disable this operator by defining \c
    QT_NO_CAST_FROM_ASCII when you compile your applications. This
    can be useful if you want to ensure that all user-visible strings
    go through QObject::tr(), for example.
*/

/*! \fn bool QString::operator>(const char *other) const

    \overload operator>()

    The \a other const char pointer is converted to a QString using
    the fromAscii() function.

    You can disable this operator by defining \c QT_NO_CAST_FROM_ASCII
    when you compile your applications. This can be useful if you want
    to ensure that all user-visible strings go through QObject::tr(),
    for example.
*/

/*! \fn bool QString::operator>=(const QString &other) const

    Returns true if this string is lexically greater than or equal to
    string \a other; otherwise returns false.

    The comparison is based exclusively on the numeric Unicode values
    of the characters and is very fast, but is not what a human would
    expect. Consider sorting user-interface strings with
    localeAwareCompare().
*/

/*! \fn bool QString::operator>=(const QLatin1String &other) const

    \overload operator>=()
*/

/*! \fn bool QString::operator>=(const QByteArray &other) const

    \overload operator>=()

    The \a other byte array is converted to a QString using the
    fromAscii() function. If any NUL characters ('\0') are embedded in
    the byte array, they will be included in the transformation.

    You can disable this operator by defining \c QT_NO_CAST_FROM_ASCII
    when you compile your applications. This can be useful if you want
    to ensure that all user-visible strings go through QObject::tr(),
    for example.
*/

/*! \fn bool QString::operator>=(const char *other) const

    \overload operator>=()

    The \a other const char pointer is converted to a QString using
    the fromAscii() function.

    You can disable this operator by defining \c QT_NO_CAST_FROM_ASCII
    when you compile your applications. This can be useful if you want
    to ensure that all user-visible strings go through QObject::tr(),
    for example.
*/

/*! \fn bool QString::operator!=(const QString &other) const

    Returns true if this string is not equal to string \a other;
    otherwise returns false.

    The comparison is based exclusively on the numeric Unicode values
    of the characters and is very fast, but is not what a human would
    expect. Consider sorting user-interface strings with
    localeAwareCompare().
*/

/*! \fn bool QString::operator!=(const QLatin1String &other) const

    \overload operator!=()
*/

/*! \fn bool QString::operator!=(const QByteArray &other) const

    \overload operator!=()

    The \a other byte array is converted to a QString using the
    fromAscii() function. If any NUL characters ('\0') are embedded
    in the byte array, they will be included in the transformation.

    You can disable this operator by defining \c QT_NO_CAST_FROM_ASCII
    when you compile your applications. This can be useful if you want
    to ensure that all user-visible strings go through QObject::tr(),
    for example.
*/

/*! \fn bool QString::operator!=(const char *other) const

    \overload operator!=()

    The \a other const char pointer is converted to a QString using
    the fromAscii() function.

    You can disable this operator by defining \c
    QT_NO_CAST_FROM_ASCII when you compile your applications. This
    can be useful if you want to ensure that all user-visible strings
    go through QObject::tr(), for example.
*/

/*!
  Returns the index position of the first occurrence of the string \a
  str in this string, searching forward from index position \a
  from. Returns -1 if \a str is not found.

  If \a cs is Qt::CaseSensitive (default), the search is case
  sensitive; otherwise the search is case insensitive.

  Example:

  \snippet doc/src/snippets/qstring/main.cpp 24

  If \a from is -1, the search starts at the last character; if it is
  -2, at the next to last character and so on.

  \sa lastIndexOf(), contains(), count()
*/
int QString::indexOf(const QString &str, int from, Qt::CaseSensitivity cs) const
{
    return qFindString(unicode(), length(), from, str.unicode(), str.length(), cs);
}

/*!
  \since 4.5
  Returns the index position of the first occurrence of the string \a
  str in this string, searching forward from index position \a
  from. Returns -1 if \a str is not found.

  If \a cs is Qt::CaseSensitive (default), the search is case
  sensitive; otherwise the search is case insensitive.

  Example:

  \snippet doc/src/snippets/qstring/main.cpp 24

  If \a from is -1, the search starts at the last character; if it is
  -2, at the next to last character and so on.

  \sa lastIndexOf(), contains(), count()
*/

int QString::indexOf(const QLatin1String &str, int from, Qt::CaseSensitivity cs) const
{
    return qt_find_latin1_string(unicode(), size(), str, from, cs);
}

int qFindString(
    const QChar *haystack0, int haystackLen, int from,
    const QChar *needle0, int needleLen, Qt::CaseSensitivity cs)
{
    const int l = haystackLen;
    const int sl = needleLen;
    if (from < 0)
        from += l;
    if (uint(sl + from) > (uint)l)
        return -1;
    if (!sl)
        return from;
    if (!l)
        return -1;

    if (sl == 1)
        return findChar(haystack0, haystackLen, needle0[0], from, cs);

    /*
        We use the Boyer-Moore algorithm in cases where the overhead
        for the skip table should pay off, otherwise we use a simple
        hash function.
    */
    if (l > 500 && sl > 5)
        return qFindStringBoyerMoore(haystack0, haystackLen, from,
            needle0, needleLen, cs);

    /*
        We use some hashing for efficiency's sake. Instead of
        comparing strings, we compare the hash value of str with that
        of a part of this QString. Only if that matches, we call
        ucstrncmp() or ucstrnicmp().
    */
    const ushort *needle = (const ushort *)needle0;
    const ushort *haystack = (const ushort *)haystack0 + from;
    const ushort *end = (const ushort *)haystack0 + (l-sl);
    const int sl_minus_1 = sl-1;
    int hashNeedle = 0, hashHaystack = 0, idx;

    if (cs == Qt::CaseSensitive) {
        for (idx = 0; idx < sl; ++idx) {
            hashNeedle = ((hashNeedle<<1) + needle[idx]);
            hashHaystack = ((hashHaystack<<1) + haystack[idx]);
        }
        hashHaystack -= haystack[sl_minus_1];

        while (haystack <= end) {
            hashHaystack += haystack[sl_minus_1];
            if (hashHaystack == hashNeedle
                 && ucstrncmp((const QChar *)needle, (const QChar *)haystack, sl) == 0)
                return haystack - (const ushort *)haystack0;

            REHASH(*haystack);
            ++haystack;
        }
    } else {
        const ushort *haystack_start = (const ushort *)haystack0;
        for (idx = 0; idx < sl; ++idx) {
            hashNeedle = (hashNeedle<<1) + foldCase(needle + idx, needle);
            hashHaystack = (hashHaystack<<1) + foldCase(haystack + idx, haystack_start);
        }
        hashHaystack -= foldCase(haystack + sl_minus_1, haystack_start);

        while (haystack <= end) {
            hashHaystack += foldCase(haystack + sl_minus_1, haystack_start);
            if (hashHaystack == hashNeedle && ucstrnicmp(needle, haystack, sl) == 0)
                return haystack - (const ushort *)haystack0;

            REHASH(foldCase(haystack, haystack_start));
            ++haystack;
        }
    }
    return -1;
}

/*!
    \overload indexOf()

    Returns the index position of the first occurrence of the
    character \a ch in the string, searching forward from index
    position \a from. Returns -1 if \a ch could not be found.
*/
int QString::indexOf(QChar ch, int from, Qt::CaseSensitivity cs) const
{
    return findChar(unicode(), length(), ch, from, cs);
}

/*!
    \since 4.8

    \overload indexOf()

    Returns the index position of the first occurrence of the string
    reference \a str in this string, searching forward from index
    position \a from. Returns -1 if \a str is not found.

    If \a cs is Qt::CaseSensitive (default), the search is case
    sensitive; otherwise the search is case insensitive.
*/
int QString::indexOf(const QStringRef &str, int from, Qt::CaseSensitivity cs) const
{
    return qFindString(unicode(), length(), from, str.unicode(), str.length(), cs);
}

static int lastIndexOfHelper(const ushort *haystack, int from, const ushort *needle, int sl, Qt::CaseSensitivity cs)
{
    /*
        See indexOf() for explanations.
    */

    const ushort *end = haystack;
    haystack += from;
    const int sl_minus_1 = sl-1;
    const ushort *n = needle+sl_minus_1;
    const ushort *h = haystack+sl_minus_1;
    int hashNeedle = 0, hashHaystack = 0, idx;

    if (cs == Qt::CaseSensitive) {
        for (idx = 0; idx < sl; ++idx) {
            hashNeedle = ((hashNeedle<<1) + *(n-idx));
            hashHaystack = ((hashHaystack<<1) + *(h-idx));
        }
        hashHaystack -= *haystack;

        while (haystack >= end) {
            hashHaystack += *haystack;
            if (hashHaystack == hashNeedle
                 && ucstrncmp((const QChar *)needle, (const QChar *)haystack, sl) == 0)
                return haystack - end;
            --haystack;
            REHASH(haystack[sl]);
        }
    } else {
        for (idx = 0; idx < sl; ++idx) {
            hashNeedle = ((hashNeedle<<1) + foldCase(n-idx, needle));
            hashHaystack = ((hashHaystack<<1) + foldCase(h-idx, end));
        }
        hashHaystack -= foldCase(haystack, end);

        while (haystack >= end) {
            hashHaystack += foldCase(haystack, end);
            if (hashHaystack == hashNeedle && ucstrnicmp(needle, haystack, sl) == 0)
                return haystack - end;
            --haystack;
            REHASH(foldCase(haystack + sl, end));
        }
    }
    return -1;
}

/*!
  Returns the index position of the last occurrence of the string \a
  str in this string, searching backward from index position \a
  from. If \a from is -1 (default), the search starts at the last
  character; if \a from is -2, at the next to last character and so
  on. Returns -1 if \a str is not found.

  If \a cs is Qt::CaseSensitive (default), the search is case
  sensitive; otherwise the search is case insensitive.

  Example:

  \snippet doc/src/snippets/qstring/main.cpp 29

  \sa indexOf(), contains(), count()
*/
int QString::lastIndexOf(const QString &str, int from, Qt::CaseSensitivity cs) const
{
    const int sl = str.d->size;
    if (sl == 1)
        return lastIndexOf(QChar(str.d->data[0]), from, cs);

    const int l = d->size;
    if (from < 0)
        from += l;
    int delta = l-sl;
    if (from == l && sl == 0)
        return from;
    if (from < 0 || from >= l || delta < 0)
        return -1;
    if (from > delta)
        from = delta;

    return lastIndexOfHelper(d->data, from, str.d->data, str.d->size, cs);
}

/*!
  \since 4.5
  \overload lastIndexOf()

  Returns the index position of the last occurrence of the string \a
  str in this string, searching backward from index position \a
  from. If \a from is -1 (default), the search starts at the last
  character; if \a from is -2, at the next to last character and so
  on. Returns -1 if \a str is not found.

  If \a cs is Qt::CaseSensitive (default), the search is case
  sensitive; otherwise the search is case insensitive.

  Example:

  \snippet doc/src/snippets/qstring/main.cpp 29

  \sa indexOf(), contains(), count()
*/
int QString::lastIndexOf(const QLatin1String &str, int from, Qt::CaseSensitivity cs) const
{
    const int sl = qstrlen(str.latin1());
    if (sl == 1)
        return lastIndexOf(QLatin1Char(str.latin1()[0]), from, cs);

    const int l = d->size;
    if (from < 0)
        from += l;
    int delta = l-sl;
    if (from == l && sl == 0)
        return from;
    if (from < 0 || from >= l || delta < 0)
        return -1;
    if (from > delta)
        from = delta;

    QVarLengthArray<ushort> s(sl);
    for (int i = 0; i < sl; ++i)
        s[i] = str.latin1()[i];

    return lastIndexOfHelper(d->data, from, s.data(), sl, cs);
}

/*!
  \overload lastIndexOf()

  Returns the index position of the last occurrence of the character
  \a ch, searching backward from position \a from.
*/
int QString::lastIndexOf(QChar ch, int from, Qt::CaseSensitivity cs) const
{
    return qt_last_index_of(unicode(), size(), ch, from, cs);
    }

/*!
  \since 4.8
  \overload lastIndexOf()

  Returns the index position of the last occurrence of the string
  reference \a str in this string, searching backward from index
  position \a from. If \a from is -1 (default), the search starts at
  the last character; if \a from is -2, at the next to last character
  and so on. Returns -1 if \a str is not found.

  If \a cs is Qt::CaseSensitive (default), the search is case
  sensitive; otherwise the search is case insensitive.

  \sa indexOf(), contains(), count()
*/
int QString::lastIndexOf(const QStringRef &str, int from, Qt::CaseSensitivity cs) const
{
    const int sl = str.size();
    if (sl == 1)
        return lastIndexOf(str.at(0), from, cs);

    const int l = d->size;
    if (from < 0)
        from += l;
    int delta = l - sl;
    if (from == l && sl == 0)
        return from;
    if (from < 0 || from >= l || delta < 0)
    return -1;
    if (from > delta)
        from = delta;

    return lastIndexOfHelper(d->data, from, reinterpret_cast<const ushort*>(str.unicode()),
                             str.size(), cs);
}

#ifndef QT_NO_REGEXP
struct QStringCapture
{
    int pos;
    int len;
    int no;
};

/*!
  \overload replace()

  Replaces every occurrence of the regular expression \a rx in the
  string with \a after. Returns a reference to the string. For
  example:

  \snippet doc/src/snippets/qstring/main.cpp 42

  For regular expressions containing \l{capturing parentheses},
  occurrences of \bold{\\1}, \bold{\\2}, ..., in \a after are replaced
  with \a{rx}.cap(1), cap(2), ...

  \snippet doc/src/snippets/qstring/main.cpp 43

  \sa indexOf(), lastIndexOf(), remove(), QRegExp::cap()
*/
QString& QString::replace(const QRegExp &rx, const QString &after)
{
    QRegExp rx2(rx);

    if (isEmpty() && rx2.indexIn(*this) == -1)
        return *this;

    realloc();

    int index = 0;
    int numCaptures = rx2.captureCount();
    int al = after.length();
    QRegExp::CaretMode caretMode = QRegExp::CaretAtZero;

    if (numCaptures > 0) {
        const QChar *uc = after.unicode();
        int numBackRefs = 0;

        for (int i = 0; i < al - 1; i++) {
            if (uc[i] == QLatin1Char('\\')) {
                int no = uc[i + 1].digitValue();
                if (no > 0 && no <= numCaptures)
                    numBackRefs++;
            }
        }

        /*
            This is the harder case where we have back-references.
        */
        if (numBackRefs > 0) {
            QVarLengthArray<QStringCapture, 16> captures(numBackRefs);
            int j = 0;

            for (int i = 0; i < al - 1; i++) {
                if (uc[i] == QLatin1Char('\\')) {
                    int no = uc[i + 1].digitValue();
                    if (no > 0 && no <= numCaptures) {
                        QStringCapture capture;
                        capture.pos = i;
                        capture.len = 2;

                        if (i < al - 2) {
                            int secondDigit = uc[i + 2].digitValue();
                            if (secondDigit != -1 && ((no * 10) + secondDigit) <= numCaptures) {
                                no = (no * 10) + secondDigit;
                                ++capture.len;
                            }
                        }

                        capture.no = no;
                        captures[j++] = capture;
                    }
                }
            }

            while (index <= length()) {
                index = rx2.indexIn(*this, index, caretMode);
                if (index == -1)
                    break;

                QString after2(after);
                for (j = numBackRefs - 1; j >= 0; j--) {
                    const QStringCapture &capture = captures[j];
                    after2.replace(capture.pos, capture.len, rx2.cap(capture.no));
                }

                replace(index, rx2.matchedLength(), after2);
                index += after2.length();

                // avoid infinite loop on 0-length matches (e.g., QRegExp("[a-z]*"))
                if (rx2.matchedLength() == 0)
                    ++index;

                caretMode = QRegExp::CaretWontMatch;
            }
            return *this;
        }
    }

    /*
        This is the simple and optimized case where we don't have
        back-references.
    */
    while (index != -1) {
        struct {
            int pos;
            int length;
        } replacements[2048];

        int pos = 0;
        int adjust = 0;
        while (pos < 2047) {
            index = rx2.indexIn(*this, index, caretMode);
            if (index == -1)
                break;
            int ml = rx2.matchedLength();
            replacements[pos].pos = index;
            replacements[pos++].length = ml;
            index += ml;
            adjust += al - ml;
            // avoid infinite loop
            if (!ml)
                index++;
        }
        if (!pos)
            break;
        replacements[pos].pos = d->size;
        int newlen = d->size + adjust;

        // to continue searching at the right position after we did
        // the first round of replacements
        if (index != -1)
            index += adjust;
        QString newstring;
        newstring.reserve(newlen + 1);
        QChar *newuc = newstring.data();
        QChar *uc = newuc;
        int copystart = 0;
        int i = 0;
        while (i < pos) {
            int copyend = replacements[i].pos;
            int size = copyend - copystart;
            memcpy(uc, d->data + copystart, size * sizeof(QChar));
            uc += size;
            memcpy(uc, after.d->data, al * sizeof(QChar));
            uc += al;
            copystart = copyend + replacements[i].length;
            i++;
        }
        memcpy(uc, d->data + copystart, (d->size - copystart) * sizeof(QChar));
        newstring.resize(newlen);
        *this = newstring;
        caretMode = QRegExp::CaretWontMatch;
    }
    return *this;
}
#endif

/*!
    Returns the number of (potentially overlapping) occurrences of
    the string \a str in this string.

    If \a cs is Qt::CaseSensitive (default), the search is
    case sensitive; otherwise the search is case insensitive.

    \sa contains(), indexOf()
*/

int QString::count(const QString &str, Qt::CaseSensitivity cs) const
{
    return qt_string_count(unicode(), size(), str.unicode(), str.size(), cs);
}

/*!
  \overload count()

  Returns the number of occurrences of character \a ch in the string.
*/

int QString::count(QChar ch, Qt::CaseSensitivity cs) const
{
    return qt_string_count(unicode(), size(), ch, cs);
    }

/*!
    \since 4.8
    \overload count()
    Returns the number of (potentially overlapping) occurrences of the
    string reference \a str in this string.

    If \a cs is Qt::CaseSensitive (default), the search is
    case sensitive; otherwise the search is case insensitive.

    \sa contains(), indexOf()
*/
int QString::count(const QStringRef &str, Qt::CaseSensitivity cs) const
{
    return qt_string_count(unicode(), size(), str.unicode(), str.size(), cs);
}


/*! \fn bool QString::contains(const QString &str, Qt::CaseSensitivity cs = Qt::CaseSensitive) const

    Returns true if this string contains an occurrence of the string
    \a str; otherwise returns false.

    If \a cs is Qt::CaseSensitive (default), the search is
    case sensitive; otherwise the search is case insensitive.

    Example:
    \snippet doc/src/snippets/qstring/main.cpp 17

    \sa indexOf(), count()
*/

/*! \fn bool QString::contains(QChar ch, Qt::CaseSensitivity cs = Qt::CaseSensitive) const

    \overload contains()

    Returns true if this string contains an occurrence of the
    character \a ch; otherwise returns false.
*/

/*! \fn bool QString::contains(const QStringRef &str, Qt::CaseSensitivity cs = Qt::CaseSensitive) const
    \since 4.8

    Returns true if this string contains an occurrence of the string
    reference \a str; otherwise returns false.

    If \a cs is Qt::CaseSensitive (default), the search is
    case sensitive; otherwise the search is case insensitive.

    \sa indexOf(), count()
*/

/*! \fn bool QString::contains(const QRegExp &rx) const

    \overload contains()

    Returns true if the regular expression \a rx matches somewhere in
    this string; otherwise returns false.
*/

/*! \fn bool QString::contains(QRegExp &rx) const
    \overload contains()
    \since 4.5

    Returns true if the regular expression \a rx matches somewhere in
    this string; otherwise returns false.

    If there is a match, the \a rx regular expression will contain the
    matched captures (see QRegExp::matchedLength, QRegExp::cap).
*/

#ifndef QT_NO_REGEXP
/*!
    \overload indexOf()

    Returns the index position of the first match of the regular
    expression \a rx in the string, searching forward from index
    position \a from. Returns -1 if \a rx didn't match anywhere.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 25
*/
int QString::indexOf(const QRegExp& rx, int from) const
{
    QRegExp rx2(rx);
    return rx2.indexIn(*this, from);
}

/*!
    \overload indexOf()
    \since 4.5

    Returns the index position of the first match of the regular
    expression \a rx in the string, searching forward from index
    position \a from. Returns -1 if \a rx didn't match anywhere.

    If there is a match, the \a rx regular expression will contain the
    matched captures (see QRegExp::matchedLength, QRegExp::cap).

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 25
*/
int QString::indexOf(QRegExp& rx, int from) const
{
    return rx.indexIn(*this, from);
}

/*!
    \overload lastIndexOf()

    Returns the index position of the last match of the regular
    expression \a rx in the string, searching backward from index
    position \a from. Returns -1 if \a rx didn't match anywhere.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 30
*/
int QString::lastIndexOf(const QRegExp& rx, int from) const
{
    QRegExp rx2(rx);
    return rx2.lastIndexIn(*this, from);
}

/*!
    \overload lastIndexOf()
    \since 4.5

    Returns the index position of the last match of the regular
    expression \a rx in the string, searching backward from index
    position \a from. Returns -1 if \a rx didn't match anywhere.

    If there is a match, the \a rx regular expression will contain the
    matched captures (see QRegExp::matchedLength, QRegExp::cap).

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 30
*/
int QString::lastIndexOf(QRegExp& rx, int from) const
{
    return rx.lastIndexIn(*this, from);
}

/*!
    \overload count()

    Returns the number of times the regular expression \a rx matches
    in the string.

    This function counts overlapping matches, so in the example
    below, there are four instances of "ana" or "ama":

    \snippet doc/src/snippets/qstring/main.cpp 18

*/
int QString::count(const QRegExp& rx) const
{
    QRegExp rx2(rx);
    int count = 0;
    int index = -1;
    int len = length();
    while (index < len - 1) {                 // count overlapping matches
        index = rx2.indexIn(*this, index + 1);
        if (index == -1)
            break;
        count++;
    }
    return count;
}
#endif // QT_NO_REGEXP

/*! \fn int QString::count() const

    \overload count()

    Same as size().
*/


/*!
    \enum QString::SectionFlag

    This enum specifies flags that can be used to affect various
    aspects of the section() function's behavior with respect to
    separators and empty fields.

    \value SectionDefault Empty fields are counted, leading and
    trailing separators are not included, and the separator is
    compared case sensitively.

    \value SectionSkipEmpty Treat empty fields as if they don't exist,
    i.e. they are not considered as far as \e start and \e end are
    concerned.

    \value SectionIncludeLeadingSep Include the leading separator (if
    any) in the result string.

    \value SectionIncludeTrailingSep Include the trailing separator
    (if any) in the result string.

    \value SectionCaseInsensitiveSeps Compare the separator
    case-insensitively.

    \sa section()
*/

/*!
    \fn QString QString::section(QChar sep, int start, int end = -1, SectionFlags flags) const

    This function returns a section of the string.

    This string is treated as a sequence of fields separated by the
    character, \a sep. The returned string consists of the fields from
    position \a start to position \a end inclusive. If \a end is not
    specified, all fields from position \a start to the end of the
    string are included. Fields are numbered 0, 1, 2, etc., counting
    from the left, and -1, -2, etc., counting from right to left.

    The \a flags argument can be used to affect some aspects of the
    function's behavior, e.g. whether to be case sensitive, whether
    to skip empty fields and how to deal with leading and trailing
    separators; see \l{SectionFlags}.

    \snippet doc/src/snippets/qstring/main.cpp 52

    If \a start or \a end is negative, we count fields from the right
    of the string, the right-most field being -1, the one from
    right-most field being -2, and so on.

    \snippet doc/src/snippets/qstring/main.cpp 53

    \sa split()
*/

/*!
    \overload section()

    \snippet doc/src/snippets/qstring/main.cpp 51
    \snippet doc/src/snippets/qstring/main.cpp 54

    \sa split()
*/

QString QString::section(const QString &sep, int start, int end, SectionFlags flags) const
{
    QStringList sections = split(sep, KeepEmptyParts,
                                 (flags & SectionCaseInsensitiveSeps) ? Qt::CaseInsensitive : Qt::CaseSensitive);
    if (sections.isEmpty())
        return QString();
    if (!(flags & SectionSkipEmpty)) {
        if (start < 0)
            start += sections.count();
        if (end < 0)
            end += sections.count();
    } else {
        int skip = 0;
        for (int k=0; k<sections.size(); ++k) {
            if (sections.at(k).isEmpty())
                skip++;
        }
        if (start < 0)
            start += sections.count() - skip;
        if (end < 0)
            end += sections.count() - skip;
    }
    int x = 0;
    QString ret;
    int first_i = start, last_i = end;
    for (int i = 0; x <= end && i < sections.size(); ++i) {
        QString section = sections.at(i);
        const bool empty = section.isEmpty();
        if (x >= start) {
            if(x == start)
                first_i = i;
            if(x == end)
                last_i = i;
            if(x > start)
                ret += sep;
            ret += section;
        }
        if (!empty || !(flags & SectionSkipEmpty))
            x++;
    }
    if((flags & SectionIncludeLeadingSep) && first_i)
        ret.prepend(sep);
    if((flags & SectionIncludeTrailingSep) && last_i < sections.size()-1)
        ret += sep;
    return ret;
}

#ifndef QT_NO_REGEXP
class qt_section_chunk {
public:
    qt_section_chunk(int l, QString s) { length = l; string = s; }
    int length;
    QString string;
};

/*!
    \overload section()

    This string is treated as a sequence of fields separated by the
    regular expression, \a reg.

    \snippet doc/src/snippets/qstring/main.cpp 55

    \warning Using this QRegExp version is much more expensive than
    the overloaded string and character versions.

    \sa split() simplified()
*/
QString QString::section(const QRegExp &reg, int start, int end, SectionFlags flags) const
{
    const QChar *uc = unicode();
    if(!uc)
        return QString();

    QRegExp sep(reg);
    sep.setCaseSensitivity((flags & SectionCaseInsensitiveSeps) ? Qt::CaseInsensitive
                                                                : Qt::CaseSensitive);

    QList<qt_section_chunk> sections;
    int n = length(), m = 0, last_m = 0, last_len = 0;
    while ((m = sep.indexIn(*this, m)) != -1) {
        sections.append(qt_section_chunk(last_len, QString(uc + last_m, m - last_m)));
        last_m = m;
        last_len = sep.matchedLength();
        m += qMax(sep.matchedLength(), 1);
    }
    sections.append(qt_section_chunk(last_len, QString(uc + last_m, n - last_m)));

    if(start < 0)
        start += sections.count();
    if(end < 0)
        end += sections.count();

    QString ret;
    int x = 0;
    int first_i = start, last_i = end;
    for (int i = 0; x <= end && i < sections.size(); ++i) {
        const qt_section_chunk &section = sections.at(i);
        const bool empty = (section.length == section.string.length());
        if (x >= start) {
            if(x == start)
                first_i = i;
            if(x == end)
                last_i = i;
            if(x != start)
                ret += section.string;
            else
                ret += section.string.mid(section.length);
        }
        if (!empty || !(flags & SectionSkipEmpty))
            x++;
    }
    if((flags & SectionIncludeLeadingSep) && first_i < sections.size()) {
        const qt_section_chunk &section = sections.at(first_i);
        ret.prepend(section.string.left(section.length));
    }
    if((flags & SectionIncludeTrailingSep) && last_i+1 <= sections.size()-1) {
        const qt_section_chunk &section = sections.at(last_i+1);
        ret += section.string.left(section.length);
    }
    return ret;
}
#endif

/*!
    Returns a substring that contains the \a n leftmost characters
    of the string.

    The entire string is returned if \a n is greater than size() or
    less than zero.

    \snippet doc/src/snippets/qstring/main.cpp 31

    \sa right(), mid(), startsWith()
*/
QString QString::left(int n)  const
{
    if (n >= d->size || n < 0)
        return *this;
    return QString((const QChar*) d->data, n);
}

/*!
    Returns a substring that contains the \a n rightmost characters
    of the string.

    The entire string is returned if \a n is greater than size() or
    less than zero.

    \snippet doc/src/snippets/qstring/main.cpp 48

    \sa left(), mid(), endsWith()
*/
QString QString::right(int n) const
{
    if (n >= d->size || n < 0)
        return *this;
    return QString((const QChar*) d->data + d->size - n, n);
}

/*!
    Returns a string that contains \a n characters of this string,
    starting at the specified \a position index.

    Returns a null string if the \a position index exceeds the
    length of the string. If there are less than \a n characters
    available in the string starting at the given \a position, or if
    \a n is -1 (default), the function returns all characters that
    are available from the specified \a position.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 34

    \sa left(), right()
*/

QString QString::mid(int position, int n) const
{
    if (d == &shared_null || position >= d->size)
        return QString();
    if (n < 0)
        n = d->size - position;
    if (position < 0) {
        n += position;
        position = 0;
    }
    if (n + position > d->size)
        n = d->size - position;
    if (position == 0 && n == d->size)
        return *this;
    return QString((const QChar*) d->data + position, n);
}

/*!
    Returns true if the string starts with \a s; otherwise returns
    false.

    If \a cs is Qt::CaseSensitive (default), the search is
    case sensitive; otherwise the search is case insensitive.

    \snippet doc/src/snippets/qstring/main.cpp 65

    \sa endsWith()
*/
bool QString::startsWith(const QString& s, Qt::CaseSensitivity cs) const
{
    return qt_starts_with(isNull() ? 0 : unicode(), size(),
                          s.isNull() ? 0 : s.unicode(), s.size(), cs);
}

/*!
  \overload startsWith()
 */
bool QString::startsWith(const QLatin1String& s, Qt::CaseSensitivity cs) const
{
    return qt_starts_with(isNull() ? 0 : unicode(), size(), s, cs);
}

/*!
  \overload startsWith()

  Returns true if the string starts with \a c; otherwise returns
  false.
*/
bool QString::startsWith(const QChar &c, Qt::CaseSensitivity cs) const
{
    return d->size
           && (cs == Qt::CaseSensitive
               ? d->data[0] == c
               : foldCase(d->data[0]) == foldCase(c.unicode()));
}

/*!
    \since 4.8
    \overload
    Returns true if the string starts with the string reference \a s;
    otherwise returns false.

    If \a cs is Qt::CaseSensitive (default), the search is case
    sensitive; otherwise the search is case insensitive.

    \sa endsWith()
*/
bool QString::startsWith(const QStringRef &s, Qt::CaseSensitivity cs) const
{
    return qt_starts_with(isNull() ? 0 : unicode(), size(),
                          s.isNull() ? 0 : s.unicode(), s.size(), cs);
}

/*!
    Returns true if the string ends with \a s; otherwise returns
    false.

    If \a cs is Qt::CaseSensitive (default), the search is case
    sensitive; otherwise the search is case insensitive.

    \snippet doc/src/snippets/qstring/main.cpp 20

    \sa startsWith()
*/
bool QString::endsWith(const QString& s, Qt::CaseSensitivity cs) const
{
    return qt_ends_with(isNull() ? 0 : unicode(), size(),
                        s.isNull() ? 0 : s.unicode(), s.size(), cs);
    }

/*!
    \since 4.8
    \overload endsWith()
    Returns true if the string ends with the string reference \a s;
    otherwise returns false.

    If \a cs is Qt::CaseSensitive (default), the search is case
    sensitive; otherwise the search is case insensitive.

    \sa startsWith()
*/
bool QString::endsWith(const QStringRef &s, Qt::CaseSensitivity cs) const
{
    return qt_ends_with(isNull() ? 0 : unicode(), size(),
                        s.isNull() ? 0 : s.unicode(), s.size(), cs);
}


/*!
    \overload endsWith()
*/
bool QString::endsWith(const QLatin1String& s, Qt::CaseSensitivity cs) const
{
    return qt_ends_with(isNull() ? 0 : unicode(), size(), s, cs);
}

/*!
  Returns true if the string ends with \a c; otherwise returns
  false.

  \overload endsWith()
 */
bool QString::endsWith(const QChar &c, Qt::CaseSensitivity cs) const
{
    return d->size
           && (cs == Qt::CaseSensitive
               ? d->data[d->size - 1] == c
               : foldCase(d->data[d->size - 1]) == foldCase(c.unicode()));
}

/*! \fn const char *QString::ascii() const
    \nonreentrant

    Use toAscii() instead.
*/

/*! \fn const char *QString::latin1() const
    \nonreentrant

    Use toLatin1() instead.
*/

/*! \fn const char *QString::utf8() const
    \nonreentrant

    Use toUtf8() instead.
*/

/*! \fn const char *QString::local8Bit() const
    \nonreentrant

    Use toLocal8Bit() instead.
*/

#if defined(QT_ALWAYS_HAVE_SSE2)
static inline __m128i mergeQuestionMarks(__m128i chunk)
{
    const __m128i questionMark = _mm_set1_epi16('?');

# ifdef __SSE4_2__
    // compare the unsigned shorts for the range 0x0100-0xFFFF
    // note on the use of _mm_cmpestrm:
    //  The MSDN documentation online (http://technet.microsoft.com/en-us/library/bb514080.aspx)
    //  says for range search the following:
    //    For each character c in a, determine whether b0 <= c <= b1 or b2 <= c <= b3
    //
    //  However, all examples on the Internet, including from Intel
    //  (see http://software.intel.com/en-us/articles/xml-parsing-accelerator-with-intel-streaming-simd-extensions-4-intel-sse4/)
    //  put the range to be searched first
    //
    //  Disassembly and instruction-level debugging with GCC and ICC show
    //  that they are doing the right thing. Inverting the arguments in the
    //  instruction does cause a bunch of test failures.

    const int mode = _SIDD_UWORD_OPS | _SIDD_CMP_RANGES | _SIDD_UNIT_MASK;
    const __m128i rangeMatch = _mm_cvtsi32_si128(0xffff0100);
    const __m128i offLimitMask = _mm_cmpestrm(rangeMatch, 2, chunk, 8, mode);

    // replace the non-Latin 1 characters in the chunk with question marks
    chunk = _mm_blendv_epi8(chunk, questionMark, offLimitMask);
# else
    // SSE has no compare instruction for unsigned comparison.
    // The variables must be shiffted + 0x8000 to be compared
    const __m128i signedBitOffset = _mm_set1_epi16(0x8000);
    const __m128i thresholdMask = _mm_set1_epi16(0xff + 0x8000);

    const __m128i signedChunk = _mm_add_epi16(chunk, signedBitOffset);
    const __m128i offLimitMask = _mm_cmpgt_epi16(signedChunk, thresholdMask);

#  ifdef __SSE4_1__
    // replace the non-Latin 1 characters in the chunk with question marks
    chunk = _mm_blendv_epi8(chunk, questionMark, offLimitMask);
#  else
    // offLimitQuestionMark contains '?' for each 16 bits that was off-limit
    // the 16 bits that were correct contains zeros
    const __m128i offLimitQuestionMark = _mm_and_si128(offLimitMask, questionMark);

    // correctBytes contains the bytes that were in limit
    // the 16 bits that were off limits contains zeros
    const __m128i correctBytes = _mm_andnot_si128(offLimitMask, chunk);

    // merge offLimitQuestionMark and correctBytes to have the result
    chunk = _mm_or_si128(correctBytes, offLimitQuestionMark);
#  endif
# endif
    return chunk;
}
#endif

static QByteArray toLatin1_helper(const QChar *data, int length)
{
    QByteArray ba;
    if (length) {
        ba.resize(length);
        const ushort *src = reinterpret_cast<const ushort *>(data);
        uchar *dst = (uchar*) ba.data();
#if defined(QT_ALWAYS_HAVE_SSE2)
        if (length >= 16) {
            const int chunkCount = length >> 4; // divided by 16

            for (int i = 0; i < chunkCount; ++i) {
                __m128i chunk1 = _mm_loadu_si128((__m128i*)src); // load
                chunk1 = mergeQuestionMarks(chunk1);
                src += 8;

                __m128i chunk2 = _mm_loadu_si128((__m128i*)src); // load
                chunk2 = mergeQuestionMarks(chunk2);
                src += 8;

                // pack the two vector to 16 x 8bits elements
                const __m128i result = _mm_packus_epi16(chunk1, chunk2);

                _mm_storeu_si128((__m128i*)dst, result); // store
                dst += 16;
            }
            length = length % 16;
        }
#elif defined(QT_ALWAYS_HAVE_NEON)
        // Refer to the documentation of the SSE2 implementation
        // this use eactly the same method as for SSE except:
        // 1) neon has unsigned comparison
        // 2) packing is done to 64 bits (8 x 8bits component).
        if (length >= 16) {
            const int chunkCount = length >> 3; // divided by 8
            const uint16x8_t questionMark = vdupq_n_u16('?'); // set
            const uint16x8_t thresholdMask = vdupq_n_u16(0xff); // set
            for (int i = 0; i < chunkCount; ++i) {
                uint16x8_t chunk = vld1q_u16((uint16_t *)src); // load
                src += 8;

                const uint16x8_t offLimitMask = vcgtq_u16(chunk, thresholdMask); // chunk > thresholdMask
                const uint16x8_t offLimitQuestionMark = vandq_u16(offLimitMask, questionMark); // offLimitMask & questionMark
                const uint16x8_t correctBytes = vbicq_u16(chunk, offLimitMask); // !offLimitMask & chunk
                chunk = vorrq_u16(correctBytes, offLimitQuestionMark); // correctBytes | offLimitQuestionMark
                const uint8x8_t result = vmovn_u16(chunk); // narrowing move->packing
                vst1_u8(dst, result); // store
                dst += 8;
            }
            length = length % 8;
        }
#endif
        while (length--) {
            *dst++ = (*src>0xff) ? '?' : (uchar) *src;
            ++src;
        }
    }
    return ba;
}

/*!
    Returns a Latin-1 representation of the string as a QByteArray.

    The returned byte array is undefined if the string contains non-Latin1
    characters. Those characters may be suppressed or replaced with a
    question mark.

    \sa fromLatin1(), toAscii(), toUtf8(), toLocal8Bit(), QTextCodec
*/
QByteArray QString::toLatin1() const
{
    return toLatin1_helper(unicode(), length());
}

// ### Qt 5: Change the return type of at least toAscii(),
// toLatin1() and unicode() such that the use of Q_COMPILER_MANGLES_RETURN_TYPE
// isn't necessary in the header. See task 177402.

/*!
    Returns an 8-bit representation of the string as a QByteArray.

    If a codec has been set using QTextCodec::setCodecForCStrings(),
    it is used to convert Unicode to 8-bit char; otherwise this
    function does the same as toLatin1().

    Note that, despite the name, this function does not necessarily return an US-ASCII
    (ANSI X3.4-1986) string and its result may not be US-ASCII compatible.

    \sa fromAscii(), toLatin1(), toUtf8(), toLocal8Bit(), QTextCodec
*/
QByteArray QString::toAscii() const
{
#ifndef QT_NO_TEXTCODEC
    if (codecForCStrings)
        return codecForCStrings->fromUnicode(*this);
#endif // QT_NO_TEXTCODEC
    return toLatin1();
}

#if !defined(Q_WS_MAC) && defined(Q_OS_UNIX)
static QByteArray toLocal8Bit_helper(const QChar *data, int length)
{
#ifndef QT_NO_TEXTCODEC
    if (QTextCodec::codecForLocale())
        return QTextCodec::codecForLocale()->fromUnicode(data, length);
#endif // QT_NO_TEXTCODEC
    return toLatin1_helper(data, length);
}
#endif

/*!
    Returns the local 8-bit representation of the string as a
    QByteArray. The returned byte array is undefined if the string
    contains characters not supported by the local 8-bit encoding.

    QTextCodec::codecForLocale() is used to perform the conversion from
    Unicode. If the locale encoding could not be determined, this function
    does the same as toLatin1().

    If this string contains any characters that cannot be encoded in the
    locale, the returned byte array is undefined. Those characters may be
    suppressed or replaced by another.

    \sa fromLocal8Bit(), toAscii(), toLatin1(), toUtf8(), QTextCodec
*/
QByteArray QString::toLocal8Bit() const
{
#ifndef QT_NO_TEXTCODEC
    if (QTextCodec::codecForLocale())
        return QTextCodec::codecForLocale()->fromUnicode(*this);
#endif // QT_NO_TEXTCODEC
    return toLatin1();
}

/*!
    Returns a UTF-8 representation of the string as a QByteArray.

    UTF-8 is a Unicode codec and can represent all characters in a Unicode
    string like QString.

    However, in the Unicode range, there are certain codepoints that are not
    considered characters. The Unicode standard reserves the last two
    codepoints in each Unicode Plane (U+FFFE, U+FFFF, U+1FFFE, U+1FFFF,
    U+2FFFE, etc.), as well as 16 codepoints in the range U+FDD0..U+FDDF,
    inclusive, as non-characters. If any of those appear in the string, they
    may be discarded and will not appear in the UTF-8 representation, or they
    may be replaced by one or more replacement characters.

    \sa fromUtf8(), toAscii(), toLatin1(), toLocal8Bit(), QTextCodec
*/
QByteArray QString::toUtf8() const
{
    if (isNull())
        return QByteArray();

    return QUtf8::convertFromUnicode(constData(), length(), 0);
}

/*!
    \since 4.2

    Returns a UCS-4/UTF-32 representation of the string as a QVector<uint>.

    UCS-4 is a Unicode codec and is lossless. All characters from this string
    can be encoded in UCS-4. The vector is not null terminated.

    \sa fromUtf8(), toAscii(), toLatin1(), toLocal8Bit(), QTextCodec, fromUcs4(), toWCharArray()
*/
QVector<uint> QString::toUcs4() const
{
    QVector<uint> v(length());
    uint *a = v.data();
    int len = toUcs4_helper<uint>(utf16(), length(), a);
    v.resize(len);
    return v;
}

QString::Data *QString::fromLatin1_helper(const char *str, int size)
{
    Data *d;
    if (!str) {
        d = &shared_null;
        d->ref.ref();
    } else if (size == 0 || (!*str && size < 0)) {
        d = &shared_empty;
        d->ref.ref();
    } else {
        if (size < 0)
            size = qstrlen(str);
        d = static_cast<Data *>(qMalloc(sizeof(Data) + size * sizeof(QChar)));
        Q_CHECK_PTR(d);
        d->ref = 1;
        d->alloc = d->size = size;
        d->clean = d->asciiCache = d->simpletext = d->righttoleft = d->capacity = 0;
        d->data = d->array;
        d->array[size] = '\0';
        ushort *dst = d->data;
        /* SIMD:
         * Unpacking with SSE has been shown to improve performance on recent CPUs
         * The same method gives no improvement with NEON.
         */
#if defined(QT_ALWAYS_HAVE_SSE2)
        if (size >= 16) {
            int chunkCount = size >> 4; // divided by 16
            const __m128i nullMask = _mm_set1_epi32(0);
            for (int i = 0; i < chunkCount; ++i) {
                const __m128i chunk = _mm_loadu_si128((__m128i*)str); // load
                str += 16;

                // unpack the first 8 bytes, padding with zeros
                const __m128i firstHalf = _mm_unpacklo_epi8(chunk, nullMask);
                _mm_storeu_si128((__m128i*)dst, firstHalf); // store
                dst += 8;

                // unpack the last 8 bytes, padding with zeros
                const __m128i secondHalf = _mm_unpackhi_epi8 (chunk, nullMask);
                _mm_storeu_si128((__m128i*)dst, secondHalf); // store
                dst += 8;
            }
            size = size % 16;
        }
#endif
        while (size--)
            *dst++ = (uchar)*str++;
    }
    return d;
}

QString::Data *QString::fromAscii_helper(const char *str, int size)
{
#ifndef QT_NO_TEXTCODEC
    if (codecForCStrings) {
        Data *d;
        if (!str) {
            d = &shared_null;
            d->ref.ref();
        } else if (size == 0 || (!*str && size < 0)) {
            d = &shared_empty;
            d->ref.ref();
        } else {
            if (size < 0)
                size = qstrlen(str);
            QString s = codecForCStrings->toUnicode(str, size);
            d = s.d;
            d->ref.ref();
        }
        return d;
    }
#endif
    return fromLatin1_helper(str, size);
}

/*!
    Returns a QString initialized with the first \a size characters
    of the Latin-1 string \a str.

    If \a size is -1 (default), it is taken to be qstrlen(\a
    str).

    \sa toLatin1(), fromAscii(), fromUtf8(), fromLocal8Bit()
*/
QString QString::fromLatin1(const char *str, int size)
{
    return QString(fromLatin1_helper(str, size), 0);
}


#ifdef QT3_SUPPORT

/*!
  \internal
*/
const char *QString::ascii_helper() const
{
    if (!asciiCache)
        asciiCache = new QHash<void *, QByteArray>();

    d->asciiCache = true;
    QByteArray ascii = toAscii();
    QByteArray old = asciiCache->value(d);
    if (old == ascii)
        return old.constData();
    asciiCache->insert(d, ascii);
    return ascii.constData();
}

/*!
  \internal
*/
const char *QString::latin1_helper() const
{
    if (!asciiCache)
        asciiCache = new QHash<void *, QByteArray>();

    d->asciiCache = true;
    QByteArray ascii = toLatin1();
    QByteArray old = asciiCache->value(d);
    if (old == ascii)
        return old.constData();
    asciiCache->insert(d, ascii);
    return ascii.constData();
}

#endif

/*!
    Returns a QString initialized with the first \a size characters
    of the 8-bit string \a str.

    If \a size is -1 (default), it is taken to be qstrlen(\a
    str).

    QTextCodec::codecForLocale() is used to perform the conversion.

    \sa toLocal8Bit(), fromAscii(), fromLatin1(), fromUtf8()
*/
QString QString::fromLocal8Bit(const char *str, int size)
{
    if (!str)
        return QString();
    if (size == 0 || (!*str && size < 0))
        return QLatin1String("");
#if !defined(QT_NO_TEXTCODEC)
    if (size < 0)
        size = qstrlen(str);
    QTextCodec *codec = QTextCodec::codecForLocale();
    if (codec)
        return codec->toUnicode(str, size);
#endif // !QT_NO_TEXTCODEC
    return fromLatin1(str, size);
}

/*!
    Returns a QString initialized with the first \a size characters
    from the string \a str.

    If \a size is -1 (default), it is taken to be qstrlen(\a
    str).

    Note that, despite the name, this function actually uses the codec
    defined by QTextCodec::setCodecForCStrings() to convert \a str to
    Unicode. Depending on the codec, it may not accept valid US-ASCII (ANSI
    X3.4-1986) input. If no codec has been set, this function does the same
    as fromLatin1().

    \sa toAscii(), fromLatin1(), fromUtf8(), fromLocal8Bit()
*/
QString QString::fromAscii(const char *str, int size)
{
    return QString(fromAscii_helper(str, size), 0);
}

/*!
    Returns a QString initialized with the first \a size bytes
    of the UTF-8 string \a str.

    If \a size is -1 (default), it is taken to be qstrlen(\a
    str).

    UTF-8 is a Unicode codec and can represent all characters in a Unicode
    string like QString. However, invalid sequences are possible with UTF-8
    and, if any such are found, they will be replaced with one or more
    "replacement characters", or suppressed. These include non-Unicode
    sequences, non-characters, overlong sequences or surrogate codepoints
    encoded into UTF-8.

    Non-characters are codepoints that the Unicode standard reserves and must
    not be used in text interchange. They are the last two codepoints in each
    Unicode Plane (U+FFFE, U+FFFF, U+1FFFE, U+1FFFF, U+2FFFE, etc.), as well
    as 16 codepoints in the range U+FDD0..U+FDDF, inclusive.

    \sa toUtf8(), fromAscii(), fromLatin1(), fromLocal8Bit()
*/
QString QString::fromUtf8(const char *str, int size)
{
    if (!str)
        return QString();
    if (size < 0)
        size = qstrlen(str);

    return QUtf8::convertToUnicode(str, size, 0);
}

/*!
    Returns a QString initialized with the first \a size characters
    of the Unicode string \a unicode (ISO-10646-UTF-16 encoded).

    If \a size is -1 (default), \a unicode must be terminated
    with a 0.

    This function checks for a Byte Order Mark (BOM). If it is missing,
    host byte order is assumed.

    This function is slow compared to the other Unicode conversions.
    Use QString(const QChar *, int) or QString(const QChar *) if possible.

    QString makes a deep copy of the Unicode data.

    \sa utf16(), setUtf16()
*/
QString QString::fromUtf16(const ushort *unicode, int size)
{
    if (!unicode)
        return QString();
    if (size < 0) {
        size = 0;
        while (unicode[size] != 0)
            ++size;
    }
    return QUtf16::convertToUnicode((const char *)unicode, size*2, 0);
}


/*!
    \since 4.2

    Returns a QString initialized with the first \a size characters
    of the Unicode string \a unicode (ISO-10646-UCS-4 encoded).

    If \a size is -1 (default), \a unicode must be terminated
    with a 0.

    \sa toUcs4(), fromUtf16(), utf16(), setUtf16(), fromWCharArray()
*/
QString QString::fromUcs4(const uint *unicode, int size)
{
    if (!unicode)
        return QString();
    if (size < 0) {
        size = 0;
        while (unicode[size] != 0)
            ++size;
    }
    return QUtf32::convertToUnicode((const char *)unicode, size*4, 0);
}

/*!
    Resizes the string to \a size characters and copies \a unicode
    into the string.

    If \a unicode is 0, nothing is copied, but the string is still
    resized to \a size.

    \sa unicode(), setUtf16()
*/
QString& QString::setUnicode(const QChar *unicode, int size)
{
     resize(size);
     if (unicode && size)
         memcpy(d->data, unicode, size * sizeof(QChar));
     return *this;
}

/*!
    \fn QString &QString::setUtf16(const ushort *unicode, int size)

    Resizes the string to \a size characters and copies \a unicode
    into the string.

    If \a unicode is 0, nothing is copied, but the string is still
    resized to \a size.

    Note that unlike fromUtf16(), this function does not consider BOMs and
    possibly differing byte ordering.

    \sa utf16(), setUnicode()
*/

/*!
    Returns a string that has whitespace removed from the start
    and the end, and that has each sequence of internal whitespace
    replaced with a single space.

    Whitespace means any character for which QChar::isSpace() returns
    true. This includes the ASCII characters '\\t', '\\n', '\\v',
    '\\f', '\\r', and ' '.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 57

    \sa trimmed()
*/
QString QString::simplified() const
{
    if (d->size == 0)
        return *this;

    const QChar * const start = reinterpret_cast<QChar *>(d->data);
    const QChar *from = start;
    const QChar *fromEnd = start + d->size;
    forever {
        QChar ch = *from;
        if (!ch.isSpace())
            break;
        if (++from == fromEnd) {
            // All-whitespace string
            shared_empty.ref.ref();
            return QString(&shared_empty, 0);
        }
    }
    // This loop needs no underflow check, as we already determined that
    // the string contains non-whitespace. If the string has exactly one
    // non-whitespace, it will be checked twice - we can live with that.
    while (fromEnd[-1].isSpace())
        fromEnd--;
    // The rest of the function depends on the fact that we already know
    // that the last character in the source is no whitespace.
    const QChar *copyFrom = from;
    int copyCount;
    forever {
        if (++from == fromEnd) {
            // Only leading and/or trailing whitespace, if any at all
            return mid(copyFrom - start, from - copyFrom);
        }
        QChar ch = *from;
        if (!ch.isSpace())
            continue;
        if (ch != QLatin1Char(' ')) {
            copyCount = from - copyFrom;
            break;
        }
        ch = *++from;
        if (ch.isSpace()) {
            copyCount = from - copyFrom - 1;
            break;
        }
    }
    // 'from' now points at the non-trailing whitespace which made the
    // string not simplified in the first place. 'copyCount' is the number
    // of already simplified characters - at least one, obviously -
    // without a trailing space.
    QString result((fromEnd - from) + copyCount, Qt::Uninitialized);
    QChar *to = reinterpret_cast<QChar *>(result.d->data);
    ::memcpy(to, copyFrom, copyCount * 2);
    to += copyCount;
    fromEnd--;
    QChar ch;
    forever {
        *to++ = QLatin1Char(' ');
        do {
            ch = *++from;
        } while (ch.isSpace());
        if (from == fromEnd)
            break;
        do {
            *to++ = ch;
            ch = *++from;
            if (from == fromEnd)
                goto done;
        } while (!ch.isSpace());
    }
  done:
    *to++ = ch;
    result.truncate(to - reinterpret_cast<QChar *>(result.d->data));
    return result;
}

/*!
    Returns a string that has whitespace removed from the start and
    the end.

    Whitespace means any character for which QChar::isSpace() returns
    true. This includes the ASCII characters '\\t', '\\n', '\\v',
    '\\f', '\\r', and ' '.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 82

    Unlike simplified(), trimmed() leaves internal whitespace alone.

    \sa simplified()
*/
QString QString::trimmed() const
{
    if (d->size == 0)
        return *this;
    const QChar *s = (const QChar*)d->data;
    if (!s->isSpace() && !s[d->size-1].isSpace())
        return *this;
    int start = 0;
    int end = d->size - 1;
    while (start<=end && s[start].isSpace())  // skip white space from start
        start++;
    if (start <= end) {                          // only white space
        while (end && s[end].isSpace())           // skip white space from end
            end--;
    }
    int l = end - start + 1;
    if (l <= 0) {
        shared_empty.ref.ref();
        return QString(&shared_empty, 0);
    }
    return QString(s + start, l);
}

/*! \fn const QChar QString::at(int position) const

    Returns the character at the given index \a position in the
    string.

    The \a position must be a valid index position in the string
    (i.e., 0 <= \a position < size()).

    \sa operator[]()
*/

/*!
    \fn QCharRef QString::operator[](int position)

    Returns the character at the specified \a position in the string as a
    modifiable reference.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 85

    The return value is of type QCharRef, a helper class for QString.
    When you get an object of type QCharRef, you can use it as if it
    were a QChar &. If you assign to it, the assignment will apply to
    the character in the QString from which you got the reference.

    \sa at()
*/

/*!
    \fn const QChar QString::operator[](int position) const

    \overload operator[]()
*/

/*! \fn QCharRef QString::operator[](uint position)

\overload operator[]()

Returns the character at the specified \a position in the string as a
modifiable reference. Equivalent to \c at(position).
*/

/*! \fn const QChar QString::operator[](uint position) const

\overload operator[]()
*/

/*!
    \fn void QString::truncate(int position)

    Truncates the string at the given \a position index.

    If the specified \a position index is beyond the end of the
    string, nothing happens.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 83

    If \a position is negative, it is equivalent to passing zero.

    \sa chop(), resize(), left()
*/

void QString::truncate(int pos)
{
    if (pos < d->size)
        resize(pos);
}


/*!
    Removes \a n characters from the end of the string.

    If \a n is greater than size(), the result is an empty string.

    Example:
    \snippet doc/src/snippets/qstring/main.cpp 15

    If you want to remove characters from the \e beginning of the
    string, use remove() instead.

    \sa truncate(), resize(), remove()
*/
void QString::chop(int n)
{
    if (n > 0)
        resize(d->size - n);
}

/*!
    Sets every character in the string to character \a ch. If \a size
    is different from -1 (default), the string is resized to \a
    size beforehand.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 21

    \sa resize()
*/

QString& QString::fill(QChar ch, int size)
{
    resize(size < 0 ? d->size : size);
    if (d->size) {
        QChar *i = (QChar*)d->data + d->size;
        QChar *b = (QChar*)d->data;
        while (i != b)
           *--i = ch;
    }
    return *this;
}

/*!
    \fn int QString::length() const

    Returns the number of characters in this string.  Equivalent to
    size().

    \sa resize()
*/

/*!
    \fn int QString::size() const

    Returns the number of characters in this string.

    The last character in the string is at position size() - 1. In
    addition, QString ensures that the character at position size()
    is always '\\0', so that you can use the return value of data()
    and constData() as arguments to functions that expect
    '\\0'-terminated strings.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 58

    \sa isEmpty(), resize()
*/

/*! \fn bool QString::isNull() const

    Returns true if this string is null; otherwise returns false.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 28

    Qt makes a distinction between null strings and empty strings for
    historical reasons. For most applications, what matters is
    whether or not a string contains any data, and this can be
    determined using the isEmpty() function.

    \sa isEmpty()
*/

/*! \fn bool QString::isEmpty() const

    Returns true if the string has no characters; otherwise returns
    false.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 27

    \sa size()
*/

/*! \fn QString &QString::operator+=(const QString &other)

    Appends the string \a other onto the end of this string and
    returns a reference to this string.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 84

    This operation is typically very fast (\l{constant time}),
    because QString preallocates extra space at the end of the string
    data so it can grow without reallocating the entire string each
    time.

    \sa append(), prepend()
*/

/*! \fn QString &QString::operator+=(const QLatin1String &str)

    \overload operator+=()

    Appends the Latin-1 string \a str to this string.
*/

/*! \fn QString &QString::operator+=(const QByteArray &ba)

    \overload operator+=()

    Appends the byte array \a ba to this string. The byte array is converted
    to Unicode using the fromAscii() function. If any NUL characters ('\0')
    are embedded in the \a ba byte array, they will be included in the
    transformation.

    You can disable this function by defining \c
    QT_NO_CAST_FROM_ASCII when you compile your applications. This
    can be useful if you want to ensure that all user-visible strings
    go through QObject::tr(), for example.
*/

/*! \fn QString &QString::operator+=(const char *str)

    \overload operator+=()

    Appends the string \a str to this string. The const char pointer
    is converted to Unicode using the fromAscii() function.

    You can disable this function by defining \c QT_NO_CAST_FROM_ASCII
    when you compile your applications. This can be useful if you want
    to ensure that all user-visible strings go through QObject::tr(),
    for example.
*/

/*! \fn QString &QString::operator+=(const QStringRef &str)

    \overload operator+=()

    Appends the string section referenced by \a str to this string.
*/

/*! \fn QString &QString::operator+=(char ch)

    \overload operator+=()

    Appends the character \a ch to this string. The character is
    converted to Unicode using the fromAscii() function.

    You can disable this function by defining \c QT_NO_CAST_FROM_ASCII
    when you compile your applications. This can be useful if you want
    to ensure that all user-visible strings go through QObject::tr(),
    for example.
*/

/*! \fn QString &QString::operator+=(QChar ch)

    \overload operator+=()

    Appends the character \a ch to the string.
*/

/*! \fn QString &QString::operator+=(QChar::SpecialCharacter c)

    \overload operator+=()

    \internal
*/

/*!
    \fn bool operator==(const char *s1, const QString &s2)

    \overload  operator==()
    \relates QString

    Returns true if \a s1 is equal to \a s2; otherwise returns false.
    Note that no string is equal to \a s1 being 0.

    Equivalent to \c {s1 != 0 && compare(s1, s2) == 0}.

    \sa QString::compare()
*/

/*!
    \fn bool operator!=(const char *s1, const QString &s2)
    \relates QString

    Returns true if \a s1 is not equal to \a s2; otherwise returns
    false.

    For \a s1 != 0, this is equivalent to \c {compare(} \a s1, \a s2
    \c {) != 0}. Note that no string is equal to \a s1 being 0.

    \sa QString::compare()
*/

/*!
    \fn bool operator<(const char *s1, const QString &s2)
    \relates QString

    Returns true if \a s1 is lexically less than \a s2; otherwise
    returns false.  For \a s1 != 0, this is equivalent to \c
    {compare(s1, s2) < 0}.

    The comparison is based exclusively on the numeric Unicode values
    of the characters and is very fast, but is not what a human would
    expect. Consider sorting user-interface strings using the
    QString::localeAwareCompare() function.

    \sa QString::compare()
*/

/*!
    \fn bool operator<=(const char *s1, const QString &s2)
    \relates QString

    Returns true if \a s1 is lexically less than or equal to \a s2;
    otherwise returns false.  For \a s1 != 0, this is equivalent to \c
    {compare(s1, s2) <= 0}.

    The comparison is based exclusively on the numeric Unicode values
    of the characters and is very fast, but is not what a human would
    expect. Consider sorting user-interface strings with
    QString::localeAwareCompare().

    \sa QString::compare()
*/

/*!
    \fn bool operator>(const char *s1, const QString &s2)
    \relates QString

    Returns true if \a s1 is lexically greater than \a s2; otherwise
    returns false.  Equivalent to \c {compare(s1, s2) > 0}.

    The comparison is based exclusively on the numeric Unicode values
    of the characters and is very fast, but is not what a human would
    expect. Consider sorting user-interface strings using the
    QString::localeAwareCompare() function.

    \sa QString::compare()
*/

/*!
    \fn bool operator>=(const char *s1, const QString &s2)
    \relates QString

    Returns true if \a s1 is lexically greater than or equal to \a s2;
    otherwise returns false.  For \a s1 != 0, this is equivalent to \c
    {compare(s1, s2) >= 0}.

    The comparison is based exclusively on the numeric Unicode values
    of the characters and is very fast, but is not what a human would
    expect. Consider sorting user-interface strings using the
    QString::localeAwareCompare() function.
*/

/*!
    \fn const QString operator+(const QString &s1, const QString &s2)
    \relates QString

    Returns a string which is the result of concatenating \a s1 and \a
    s2.
*/

/*!
    \fn const QString operator+(const QString &s1, const char *s2)
    \relates QString

    Returns a string which is the result of concatenating \a s1 and \a
    s2 (\a s2 is converted to Unicode using the QString::fromAscii()
    function).

    \sa QString::fromAscii()
*/

/*!
    \fn const QString operator+(const char *s1, const QString &s2)
    \relates QString

    Returns a string which is the result of concatenating \a s1 and \a
    s2 (\a s1 is converted to Unicode using the QString::fromAscii()
    function).

    \sa QString::fromAscii()
*/

/*!
    \fn const QString operator+(const QString &s, char ch)
    \relates QString

    Returns a string which is the result of concatenating the string
    \a s and the character \a ch.
*/

/*!
    \fn const QString operator+(char ch, const QString &s)
    \relates QString

    Returns a string which is the result of concatenating the
    character \a ch and the string \a s.
*/

/*!
    \fn int QString::compare(const QString &s1, const QString &s2, Qt::CaseSensitivity cs)
    \since 4.2

    Compares \a s1 with \a s2 and returns an integer less than, equal
    to, or greater than zero if \a s1 is less than, equal to, or
    greater than \a s2.

    If \a cs is Qt::CaseSensitive, the comparison is case sensitive;
    otherwise the comparison is case insensitive.

    Case sensitive comparison is based exclusively on the numeric
    Unicode values of the characters and is very fast, but is not what
    a human would expect.  Consider sorting user-visible strings with
    localeAwareCompare().

    \snippet doc/src/snippets/qstring/main.cpp 16

    \sa operator==(), operator<(), operator>()
*/

/*!
    \fn int QString::compare(const QString & s1, const QString & s2)

    \overload compare()

    Performs a case sensitive compare of \a s1 and \a s2.
*/

/*!
    \fn int QString::compare(const QString &s1, const QLatin1String &s2, Qt::CaseSensitivity cs)
    \since 4.2
    \overload compare()

    Performs a comparison of \a s1 and \a s2, using the case
    sensitivity setting \a cs.
*/

/*!
    \fn int QString::compare(const QLatin1String &s1, const QString &s2, Qt::CaseSensitivity cs = Qt::CaseSensitive)

    \since 4.2
    \overload compare()

    Performs a comparison of \a s1 and \a s2, using the case
    sensitivity setting \a cs.
*/

/*!
    \overload compare()

    Lexically compares this string with the \a other string and
    returns an integer less than, equal to, or greater than zero if
    this string is less than, equal to, or greater than the other
    string.

    Equivalent to \c {compare(*this, other)}.
*/
int QString::compare(const QString &other) const
{
    return ucstrcmp(constData(), length(), other.constData(), other.length());
}

/*!
    \overload compare()
    \since 4.2

    Same as compare(*this, \a other, \a cs).
*/
int QString::compare(const QString &other, Qt::CaseSensitivity cs) const
{
    if (cs == Qt::CaseSensitive)
        return ucstrcmp(constData(), length(), other.constData(), other.length());
    return ucstricmp(d->data, d->data + d->size, other.d->data, other.d->data + other.d->size);
}

/*!
    \internal
    \since 4.5
*/
int QString::compare_helper(const QChar *data1, int length1, const QChar *data2, int length2,
                            Qt::CaseSensitivity cs)
{
    if (cs == Qt::CaseSensitive)
        return ucstrcmp(data1, length1, data2, length2);
    register const ushort *s1 = reinterpret_cast<const ushort *>(data1);
    register const ushort *s2 = reinterpret_cast<const ushort *>(data2);
    return ucstricmp(s1, s1 + length1, s2, s2 + length2);
}

/*!
    \overload compare()
    \since 4.2

    Same as compare(*this, \a other, \a cs).
*/
int QString::compare(const QLatin1String &other, Qt::CaseSensitivity cs) const
{
    return compare_helper(unicode(), length(), other, cs);
}

/*!
  \fn int QString::compare(const QStringRef &ref, Qt::CaseSensitivity cs = Qt::CaseSensitive) const
  \overload compare()

  Compares the string reference, \a ref, with the string and returns
  an integer less than, equal to, or greater than zero if the string
  is less than, equal to, or greater than \a ref.
*/

/*!
  \fn int QString::compare(const QString &s1, const QStringRef &s2, Qt::CaseSensitivity cs = Qt::CaseSensitive)
  \overload compare()
*/

/*!
    \internal
    \since 4.5
*/
int QString::compare_helper(const QChar *data1, int length1, QLatin1String s2,
                            Qt::CaseSensitivity cs)
{
    const ushort *uc = reinterpret_cast<const ushort *>(data1);
    const ushort *e = uc + length1;
    const uchar *c = (uchar *)s2.latin1();

    if (!c)
        return length1;

    if (cs == Qt::CaseSensitive) {
        while (uc < e && *c && *uc == *c)
            uc++, c++;

        if (uc == e)
            return -*c;

        return *uc - *c;
    } else {
        return ucstricmp(uc, e, c);
    }
}

/*!
    \fn int QString::localeAwareCompare(const QString & s1, const QString & s2)

    Compares \a s1 with \a s2 and returns an integer less than, equal
    to, or greater than zero if \a s1 is less than, equal to, or
    greater than \a s2.

    The comparison is performed in a locale- and also
    platform-dependent manner. Use this function to present sorted
    lists of strings to the user.

    On Mac OS X since Qt 4.3, this function compares according the
    "Order for sorted lists" setting in the International prefereces panel.

    \sa compare(), QTextCodec::locale()
*/

/*!
    \fn int QString::localeAwareCompare(const QStringRef &other) const
    \since 4.5
    \overload localeAwareCompare()

    Compares this string with the \a other string and returns an
    integer less than, equal to, or greater than zero if this string
    is less than, equal to, or greater than the \a other string.

    The comparison is performed in a locale- and also
    platform-dependent manner. Use this function to present sorted
    lists of strings to the user.

    Same as \c {localeAwareCompare(*this, other)}.
*/

/*!
    \fn int QString::localeAwareCompare(const QString &s1, const QStringRef &s2)
    \since 4.5
    \overload localeAwareCompare()

    Compares \a s1 with \a s2 and returns an integer less than, equal
    to, or greater than zero if \a s1 is less than, equal to, or
    greater than \a s2.

    The comparison is performed in a locale- and also
    platform-dependent manner. Use this function to present sorted
    lists of strings to the user.
*/


#if !defined(CSTR_LESS_THAN)
#define CSTR_LESS_THAN    1
#define CSTR_EQUAL        2
#define CSTR_GREATER_THAN 3
#endif

/*!
    \overload localeAwareCompare()

    Compares this string with the \a other string and returns an
    integer less than, equal to, or greater than zero if this string
    is less than, equal to, or greater than the \a other string.

    The comparison is performed in a locale- and also
    platform-dependent manner. Use this function to present sorted
    lists of strings to the user.

    Same as \c {localeAwareCompare(*this, other)}.
*/
int QString::localeAwareCompare(const QString &other) const
{
    return localeAwareCompare_helper(constData(), length(), other.constData(), other.length());
}

#if defined(Q_OS_WIN32) || defined(Q_OS_WINCE)
QT_END_NAMESPACE
#include "qt_windows.h"
QT_BEGIN_NAMESPACE
#endif

/*!
    \internal
    \since 4.5
*/
int QString::localeAwareCompare_helper(const QChar *data1, int length1,
                                       const QChar *data2, int length2)
{
    // do the right thing for null and empty
    if (length1 == 0 || length2 == 0)
        return ucstrcmp(data1, length1, data2, length2);

#if defined(Q_OS_WIN32) || defined(Q_OS_WINCE)
    int res = CompareString(GetUserDefaultLCID(), 0, (wchar_t*)data1, length1, (wchar_t*)data2, length2);

    switch (res) {
    case CSTR_LESS_THAN:
        return -1;
    case CSTR_GREATER_THAN:
        return 1;
    default:
        return 0;
    }
#elif defined (Q_OS_MAC)
    // Use CFStringCompare for comparing strings on Mac. This makes Qt order
    // strings the same way as native applications do, and also respects
    // the "Order for sorted lists" setting in the International preferences
    // panel.
    const CFStringRef thisString =
        CFStringCreateWithCharactersNoCopy(kCFAllocatorDefault,
            reinterpret_cast<const UniChar *>(data1), length1, kCFAllocatorNull);
    const CFStringRef otherString =
        CFStringCreateWithCharactersNoCopy(kCFAllocatorDefault,
            reinterpret_cast<const UniChar *>(data2), length2, kCFAllocatorNull);

    const int result = CFStringCompare(thisString, otherString, kCFCompareLocalized);
    CFRelease(thisString);
    CFRelease(otherString);
    return result;
#elif defined(Q_OS_SYMBIAN)
    TPtrC p1 = TPtrC16(reinterpret_cast<const TUint16 *>(data1), length1);
    TPtrC p2 = TPtrC16(reinterpret_cast<const TUint16 *>(data2), length2);
    return p1.CompareC(p2);
#elif defined(Q_OS_UNIX)
#  if defined(QT_USE_ICU)
    int res;
    if (qt_ucol_strcoll(data1, length1, data2, length2, &res)) {
        if (res == 0)
            res = ucstrcmp(data1, length1, data2, length2);
        return res;
    } // else fall through
#  endif
    // declared in <string.h>
    int delta = strcoll(toLocal8Bit_helper(data1, length1), toLocal8Bit_helper(data2, length2));
    if (delta == 0)
        delta = ucstrcmp(data1, length1, data2, length2);
    return delta;
#else
    return ucstrcmp(data1, length1, data2, length2);
#endif
}


/*!
    \fn const QChar *QString::unicode() const

    Returns a '\\0'-terminated Unicode representation of the string.
    The result remains valid until the string is modified.

    \sa utf16()
*/

/*!
    \fn const ushort *QString::utf16() const

    Returns the QString as a '\\0\'-terminated array of unsigned
    shorts. The result remains valid until the string is modified.

    The returned string is in host byte order.

    \sa unicode()
*/

const ushort *QString::utf16() const
{
    if (d->data != d->array) {
        QString *that = const_cast<QString*>(this);
        that->realloc();   // ensure '\\0'-termination for ::fromRawData strings
        return that->d->data;
    }
    return d->array;
}

/*!
    Returns a string of size \a width that contains this string
    padded by the \a fill character.

    If \a truncate is false and the size() of the string is more than
    \a width, then the returned string is a copy of the string.

    \snippet doc/src/snippets/qstring/main.cpp 32

    If \a truncate is true and the size() of the string is more than
    \a width, then any characters in a copy of the string after
    position \a width are removed, and the copy is returned.

    \snippet doc/src/snippets/qstring/main.cpp 33

    \sa rightJustified()
*/

QString QString::leftJustified(int width, QChar fill, bool truncate) const
{
    QString result;
    int len = length();
    int padlen = width - len;
    if (padlen > 0) {
        result.resize(len+padlen);
        if (len)
            memcpy(result.d->data, d->data, sizeof(QChar)*len);
        QChar *uc = (QChar*)result.d->data + len;
        while (padlen--)
           * uc++ = fill;
    } else {
        if (truncate)
            result = left(width);
        else
            result = *this;
    }
    return result;
}

/*!
    Returns a string of size() \a width that contains the \a fill
    character followed by the string. For example:

    \snippet doc/src/snippets/qstring/main.cpp 49

    If \a truncate is false and the size() of the string is more than
    \a width, then the returned string is a copy of the string.

    If \a truncate is true and the size() of the string is more than
    \a width, then the resulting string is truncated at position \a
    width.

    \snippet doc/src/snippets/qstring/main.cpp 50

    \sa leftJustified()
*/

QString QString::rightJustified(int width, QChar fill, bool truncate) const
{
    QString result;
    int len = length();
    int padlen = width - len;
    if (padlen > 0) {
        result.resize(len+padlen);
        QChar *uc = (QChar*)result.d->data;
        while (padlen--)
           * uc++ = fill;
        if (len)
            memcpy(uc, d->data, sizeof(QChar)*len);
    } else {
        if (truncate)
            result = left(width);
        else
            result = *this;
    }
    return result;
}

/*!
    Returns a lowercase copy of the string.

    \snippet doc/src/snippets/qstring/main.cpp 75

    The case conversion will always happen in the 'C' locale. For locale dependent
    case folding use QLocale::toLower()

    \sa toUpper(), QLocale::toLower()
*/

QString QString::toLower() const
{
    const ushort *p = d->data;
    if (!p)
        return *this;
    if (!d->size)
        return *this;

    const ushort *e = d->data + d->size;

    // this avoids one out of bounds check in the loop
    if (QChar(*p).isLowSurrogate())
        ++p;

    while (p != e) {
        uint c = *p;
        if (QChar(c).isLowSurrogate() && QChar(*(p - 1)).isHighSurrogate())
            c = QChar::surrogateToUcs4(*(p - 1), c);
        const QUnicodeTables::Properties *prop = qGetProp(c);
        if (prop->lowerCaseDiff || prop->lowerCaseSpecial) {
            QString s(d->size, Qt::Uninitialized);
            memcpy(s.d->data, d->data, (p - d->data)*sizeof(ushort));
            ushort *pp = s.d->data + (p - d->data);
            while (p < e) {
                uint c = *p;
                if (QChar(c).isLowSurrogate() && QChar(*(p - 1)).isHighSurrogate())
                    c = QChar::surrogateToUcs4(*(p - 1), c);
                prop = qGetProp(c);
                if (prop->lowerCaseSpecial) {
                    int pos = pp - s.d->data;
                    s.resize(s.d->size + SPECIAL_CASE_MAX_LEN);
                    pp = s.d->data + pos;
                    const ushort *specialCase = specialCaseMap + prop->lowerCaseDiff;
                    while (*specialCase)
                        *pp++ = *specialCase++;
                } else {
                    *pp++ = *p + prop->lowerCaseDiff;
                }
                ++p;
            }
            s.truncate(pp - s.d->data);
            return s;
        }
        ++p;
    }
    return *this;
}

/*!
    Returns the case folded equivalent of the string. For most Unicode
    characters this is the same as toLower().
*/
QString QString::toCaseFolded() const
{
    if (!d->size)
        return *this;

    const ushort *p = d->data;
    if (!p)
        return *this;

    const ushort *e = d->data + d->size;

    uint last = 0;
    while (p < e) {
        ushort folded = foldCase(*p, last);
        if (folded != *p) {
            QString s(*this);
            s.detach();
            ushort *pp = s.d->data + (p - d->data);
            const ushort *ppe = s.d->data + s.d->size;
            last = pp > s.d->data ? *(pp - 1) : 0;
            while (pp < ppe) {
                *pp = foldCase(*pp, last);
                ++pp;
            }
            return s;
        }
        p++;
    }
    return *this;
}

/*!
    Returns an uppercase copy of the string.

    \snippet doc/src/snippets/qstring/main.cpp 81

    The case conversion will always happen in the 'C' locale. For locale dependent
    case folding use QLocale::toUpper()

    \sa toLower(), QLocale::toLower()
*/

QString QString::toUpper() const
{
    const ushort *p = d->data;
    if (!p)
        return *this;
    if (!d->size)
        return *this;

    const ushort *e = d->data + d->size;

    // this avoids one out of bounds check in the loop
    if (QChar(*p).isLowSurrogate())
        ++p;

    while (p != e) {
        uint c = *p;
        if (QChar(c).isLowSurrogate() && QChar(*(p - 1)).isHighSurrogate())
            c = QChar::surrogateToUcs4(*(p - 1), c);
        const QUnicodeTables::Properties *prop = qGetProp(c);
        if (prop->upperCaseDiff || prop->upperCaseSpecial) {
            QString s(d->size, Qt::Uninitialized);
            memcpy(s.d->data, d->data, (p - d->data)*sizeof(ushort));
            ushort *pp = s.d->data + (p - d->data);
            while (p < e) {
                uint c = *p;
                if (QChar(c).isLowSurrogate() && QChar(*(p - 1)).isHighSurrogate())
                    c = QChar::surrogateToUcs4(*(p - 1), c);
                prop = qGetProp(c);
                if (prop->upperCaseSpecial) {
                    int pos = pp - s.d->data;
                    s.resize(s.d->size + SPECIAL_CASE_MAX_LEN);
                    pp = s.d->data + pos;
                    const ushort *specialCase = specialCaseMap + prop->upperCaseDiff;
                    while (*specialCase)
                        *pp++ = *specialCase++;
                } else {
                    *pp++ = *p + prop->upperCaseDiff;
                }
                ++p;
            }
            s.truncate(pp - s.d->data);
            return s;
        }
        ++p;
    }
    return *this;
}

// ### Qt 5: Consider whether this function shouldn't be removed See task 202871.
/*!
    Safely builds a formatted string from the format string \a cformat
    and an arbitrary list of arguments.

    The %lc escape sequence expects a unicode character of type ushort
    (as returned by QChar::unicode()). The %ls escape sequence expects
    a pointer to a zero-terminated array of unicode characters of type
    ushort (as returned by QString::utf16()).

    \note This function expects a UTF-8 string for %s and Latin-1 for
    the format string.

    The format string supports most of the conversion specifiers
    provided by printf() in the standard C++ library. It doesn't
    honor the length modifiers (e.g. \c h for \c short, \c ll for
    \c{long long}). If you need those, use the standard snprintf()
    function instead:

    \snippet doc/src/snippets/qstring/main.cpp 63

    \warning We do not recommend using QString::sprintf() in new Qt
    code. Instead, consider using QTextStream or arg(), both of
    which support Unicode strings seamlessly and are type-safe.
    Here's an example that uses QTextStream:

    \snippet doc/src/snippets/qstring/main.cpp 64

    For \l {QObject::tr()}{translations}, especially if the strings
    contains more than one escape sequence, you should consider using
    the arg() function instead. This allows the order of the
    replacements to be controlled by the translator.

    \sa arg()
*/

QString &QString::sprintf(const char *cformat, ...)
{
    va_list ap;
    va_start(ap, cformat);
    QString &s = vsprintf(cformat, ap);
    va_end(ap);
    return s;
}

/*!
    Equivalent method to sprintf(), but takes a va_list \a ap
    instead a list of variable arguments. See the sprintf()
    documentation for an explanation of \a cformat.

    This method does not call the va_end macro, the caller
    is responsible to call va_end on \a ap.

    \sa sprintf()
*/

QString &QString::vsprintf(const char* cformat, va_list ap)
{
    QLocale locale(QLocale::C);

    if (!cformat || !*cformat) {
        // Qt 1.x compat
        *this = fromLatin1("");
        return *this;
    }

    // Parse cformat

    QString result;
    const char *c = cformat;
    for (;;) {
        // Copy non-escape chars to result
#ifndef QT_NO_TEXTCODEC
        int i = 0;
        while (*(c + i) != '\0' && *(c + i) != '%')
            ++i;
        if (codecForCStrings)
            result.append(codecForCStrings->toUnicode(c, i));
        else
            result.append(fromLatin1(c, i));
        c += i;
#else
        while (*c != '\0' && *c != '%')
            result.append(QLatin1Char(*c++));
#endif

        if (*c == '\0')
            break;

        // Found '%'
        const char *escape_start = c;
        ++c;

        if (*c == '\0') {
            result.append(QLatin1Char('%')); // a % at the end of the string - treat as non-escape text
            break;
        }
        if (*c == '%') {
            result.append(QLatin1Char('%')); // %%
            ++c;
            continue;
        }

        // Parse flag characters
        uint flags = 0;
        bool no_more_flags = false;
        do {
            switch (*c) {
                case '#': flags |= QLocalePrivate::Alternate; break;
                case '0': flags |= QLocalePrivate::ZeroPadded; break;
                case '-': flags |= QLocalePrivate::LeftAdjusted; break;
                case ' ': flags |= QLocalePrivate::BlankBeforePositive; break;
                case '+': flags |= QLocalePrivate::AlwaysShowSign; break;
                case '\'': flags |= QLocalePrivate::ThousandsGroup; break;
                default: no_more_flags = true; break;
            }

            if (!no_more_flags)
                ++c;
        } while (!no_more_flags);

        if (*c == '\0') {
            result.append(QLatin1String(escape_start)); // incomplete escape, treat as non-escape text
            break;
        }

        // Parse field width
        int width = -1; // -1 means unspecified
        if (qIsDigit(*c)) {
            QString width_str;
            while (*c != '\0' && qIsDigit(*c))
                width_str.append(QLatin1Char(*c++));

            // can't be negative - started with a digit
            // contains at least one digit
            width = width_str.toInt();
        }
        else if (*c == '*') {
            width = va_arg(ap, int);
            if (width < 0)
                width = -1; // treat all negative numbers as unspecified
            ++c;
        }

        if (*c == '\0') {
            result.append(QLatin1String(escape_start)); // incomplete escape, treat as non-escape text
            break;
        }

        // Parse precision
        int precision = -1; // -1 means unspecified
        if (*c == '.') {
            ++c;
            if (qIsDigit(*c)) {
                QString precision_str;
                while (*c != '\0' && qIsDigit(*c))
                    precision_str.append(QLatin1Char(*c++));

                // can't be negative - started with a digit
                // contains at least one digit
                precision = precision_str.toInt();
            }
            else if (*c == '*') {
                precision = va_arg(ap, int);
                if (precision < 0)
                    precision = -1; // treat all negative numbers as unspecified
                ++c;
            }
        }

        if (*c == '\0') {
            result.append(QLatin1String(escape_start)); // incomplete escape, treat as non-escape text
            break;
        }

        // Parse the length modifier
        enum LengthMod { lm_none, lm_hh, lm_h, lm_l, lm_ll, lm_L, lm_j, lm_z, lm_t };
        LengthMod length_mod = lm_none;
        switch (*c) {
            case 'h':
                ++c;
                if (*c == 'h') {
                    length_mod = lm_hh;
                    ++c;
                }
                else
                    length_mod = lm_h;
                break;

            case 'l':
                ++c;
                if (*c == 'l') {
                    length_mod = lm_ll;
                    ++c;
                }
                else
                    length_mod = lm_l;
                break;

            case 'L':
                ++c;
                length_mod = lm_L;
                break;

            case 'j':
                ++c;
                length_mod = lm_j;
                break;

            case 'z':
            case 'Z':
                ++c;
                length_mod = lm_z;
                break;

            case 't':
                ++c;
                length_mod = lm_t;
                break;

            default: break;
        }

        if (*c == '\0') {
            result.append(QLatin1String(escape_start)); // incomplete escape, treat as non-escape text
            break;
        }

        // Parse the conversion specifier and do the conversion
        QString subst;
        switch (*c) {
            case 'd':
            case 'i': {
                qint64 i;
                switch (length_mod) {
                    case lm_none: i = va_arg(ap, int); break;
                    case lm_hh: i = va_arg(ap, int); break;
                    case lm_h: i = va_arg(ap, int); break;
                    case lm_l: i = va_arg(ap, long int); break;
                    case lm_ll: i = va_arg(ap, qint64); break;
                    case lm_j: i = va_arg(ap, long int); break;
                    case lm_z: i = va_arg(ap, size_t); break;
                    case lm_t: i = va_arg(ap, int); break;
                    default: i = 0; break;
                }
                subst = locale.d()->longLongToString(i, precision, 10, width, flags);
                ++c;
                break;
            }
            case 'o':
            case 'u':
            case 'x':
            case 'X': {
                quint64 u;
                switch (length_mod) {
                    case lm_none: u = va_arg(ap, uint); break;
                    case lm_hh: u = va_arg(ap, uint); break;
                    case lm_h: u = va_arg(ap, uint); break;
                    case lm_l: u = va_arg(ap, ulong); break;
                    case lm_ll: u = va_arg(ap, quint64); break;
                    case lm_z: u = va_arg(ap, size_t); break;
                    default: u = 0; break;
                }

                if (qIsUpper(*c))
                    flags |= QLocalePrivate::CapitalEorX;

                int base = 10;
                switch (qToLower(*c)) {
                    case 'o':
                        base = 8; break;
                    case 'u':
                        base = 10; break;
                    case 'x':
                        base = 16; break;
                    default: break;
                }
                subst = locale.d()->unsLongLongToString(u, precision, base, width, flags);
                ++c;
                break;
            }
            case 'E':
            case 'e':
            case 'F':
            case 'f':
            case 'G':
            case 'g':
            case 'A':
            case 'a': {
                double d;
                if (length_mod == lm_L)
                    d = va_arg(ap, long double); // not supported - converted to a double
                else
                    d = va_arg(ap, double);

                if (qIsUpper(*c))
                    flags |= QLocalePrivate::CapitalEorX;

                QLocalePrivate::DoubleForm form = QLocalePrivate::DFDecimal;
                switch (qToLower(*c)) {
                    case 'e': form = QLocalePrivate::DFExponent; break;
                    case 'a':                             // not supported - decimal form used instead
                    case 'f': form = QLocalePrivate::DFDecimal; break;
                    case 'g': form = QLocalePrivate::DFSignificantDigits; break;
                    default: break;
                }
                subst = locale.d()->doubleToString(d, precision, form, width, flags);
                ++c;
                break;
            }
            case 'c': {
                if (length_mod == lm_l)
                    subst = QChar((ushort) va_arg(ap, int));
                else
                    subst = QLatin1Char((uchar) va_arg(ap, int));
                ++c;
                break;
            }
            case 's': {
                if (length_mod == lm_l) {
                    const ushort *buff = va_arg(ap, const ushort*);
                    const ushort *ch = buff;
                    while (*ch != 0)
                        ++ch;
                    subst.setUtf16(buff, ch - buff);
                } else
                    subst = QString::fromUtf8(va_arg(ap, const char*));
                if (precision != -1)
                    subst.truncate(precision);
                ++c;
                break;
            }
            case 'p': {
                void *arg = va_arg(ap, void*);
#ifdef Q_OS_WIN64
                quint64 i = reinterpret_cast<quint64>(arg);
#else
                quint64 i = reinterpret_cast<unsigned long>(arg);
#endif
                flags |= QLocalePrivate::Alternate;
                subst = locale.d()->unsLongLongToString(i, precision, 16, width, flags);
                ++c;
                break;
            }
            case 'n':
                switch (length_mod) {
                    case lm_hh: {
                        signed char *n = va_arg(ap, signed char*);
                        *n = result.length();
                        break;
                    }
                    case lm_h: {
                        short int *n = va_arg(ap, short int*);
                        *n = result.length();
                            break;
                    }
                    case lm_l: {
                        long int *n = va_arg(ap, long int*);
                        *n = result.length();
                        break;
                    }
                    case lm_ll: {
                        qint64 *n = va_arg(ap, qint64*);
                        volatile uint tmp = result.length(); // egcs-2.91.66 gets internal
                        *n = tmp;                             // compiler error without volatile
                        break;
                    }
                    default: {
                        int *n = va_arg(ap, int*);
                        *n = result.length();
                        break;
                    }
                }
                ++c;
                break;

            default: // bad escape, treat as non-escape text
                for (const char *cc = escape_start; cc != c; ++cc)
                    result.append(QLatin1Char(*cc));
                continue;
        }

        if (flags & QLocalePrivate::LeftAdjusted)
            result.append(subst.leftJustified(width));
        else
            result.append(subst.rightJustified(width));
    }

    *this = result;

    return *this;
}

/*!
    Returns the string converted to a \c{long long} using base \a
    base, which is 10 by default and must be between 2 and 36, or 0.
    Returns 0 if the conversion fails.

    If a conversion error occurs, *\a{ok} is set to false; otherwise
    *\a{ok} is set to true.

    If \a base is 0, the C language convention is used: If the string
    begins with "0x", base 16 is used; if the string begins with "0",
    base 8 is used; otherwise, base 10 is used.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 74

    \sa number(), toULongLong(), toInt()
*/

qint64 QString::toLongLong(bool *ok, int base) const
{
#if defined(QT_CHECK_RANGE)
    if (base != 0 && (base < 2 || base > 36)) {
        qWarning("QString::toLongLong: Invalid base (%d)", base);
        base = 10;
    }
#endif

    bool my_ok;
    QLocale def_locale;
    qint64 result = def_locale.d()->stringToLongLong(*this, base, &my_ok, QLocalePrivate::FailOnGroupSeparators);
    if (my_ok) {
        if (ok != 0)
            *ok = true;
        return result;
    }

    QLocale c_locale(QLocale::C);
    return c_locale.d()->stringToLongLong(*this, base, ok, QLocalePrivate::FailOnGroupSeparators);
}

/*!
    Returns the string converted to an \c{unsigned long long} using base \a
    base, which is 10 by default and must be between 2 and 36, or 0.
    Returns 0 if the conversion fails.

    If a conversion error occurs, *\a{ok} is set to false; otherwise
    *\a{ok} is set to true.

    If \a base is 0, the C language convention is used: If the string
    begins with "0x", base 16 is used; if the string begins with "0",
    base 8 is used; otherwise, base 10 is used.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 79

    \sa number(), toLongLong()
*/

quint64 QString::toULongLong(bool *ok, int base) const
{
#if defined(QT_CHECK_RANGE)
    if (base != 0 && (base < 2 || base > 36)) {
        qWarning("QString::toULongLong: Invalid base (%d)", base);
        base = 10;
    }
#endif

    bool my_ok;
    QLocale def_locale;
    quint64 result = def_locale.d()->stringToUnsLongLong(*this, base, &my_ok, QLocalePrivate::FailOnGroupSeparators);
    if (my_ok) {
        if (ok != 0)
            *ok = true;
        return result;
    }

    QLocale c_locale(QLocale::C);
    return c_locale.d()->stringToUnsLongLong(*this, base, ok, QLocalePrivate::FailOnGroupSeparators);
}

/*!
    \fn long QString::toLong(bool *ok, int base) const

    Returns the string converted to a \c long using base \a
    base, which is 10 by default and must be between 2 and 36, or 0.
    Returns 0 if the conversion fails.

    If a conversion error occurs, *\a{ok} is set to false; otherwise
    *\a{ok} is set to true.

    If \a base is 0, the C language convention is used: If the string
    begins with "0x", base 16 is used; if the string begins with "0",
    base 8 is used; otherwise, base 10 is used.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 73

    \sa number(), toULong(), toInt()
*/

long QString::toLong(bool *ok, int base) const
{
    qint64 v = toLongLong(ok, base);
    if (v < LONG_MIN || v > LONG_MAX) {
        if (ok)
            *ok = false;
        v = 0;
    }
    return (long)v;
}

/*!
    \fn ulong QString::toULong(bool *ok, int base) const

    Returns the string converted to an \c{unsigned long} using base \a
    base, which is 10 by default and must be between 2 and 36, or 0.
    Returns 0 if the conversion fails.

    If a conversion error occurs, *\a{ok} is set to false; otherwise
    *\a{ok} is set to true.

    If \a base is 0, the C language convention is used: If the string
    begins with "0x", base 16 is used; if the string begins with "0",
    base 8 is used; otherwise, base 10 is used.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 78

    \sa number()
*/

ulong QString::toULong(bool *ok, int base) const
{
    quint64 v = toULongLong(ok, base);
    if (v > ULONG_MAX) {
        if (ok)
            *ok = false;
        v = 0;
    }
    return (ulong)v;
}


/*!
    Returns the string converted to an \c int using base \a
    base, which is 10 by default and must be between 2 and 36, or 0.
    Returns 0 if the conversion fails.

    If a conversion error occurs, *\a{ok} is set to false; otherwise
    *\a{ok} is set to true.

    If \a base is 0, the C language convention is used: If the string
    begins with "0x", base 16 is used; if the string begins with "0",
    base 8 is used; otherwise, base 10 is used.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 72

    \sa number(), toUInt(), toDouble()
*/

int QString::toInt(bool *ok, int base) const
{
    qint64 v = toLongLong(ok, base);
    if (v < INT_MIN || v > INT_MAX) {
        if (ok)
            *ok = false;
        v = 0;
    }
    return v;
}

/*!
    Returns the string converted to an \c{unsigned int} using base \a
    base, which is 10 by default and must be between 2 and 36, or 0.
    Returns 0 if the conversion fails.

    If a conversion error occurs, *\a{ok} is set to false; otherwise
    *\a{ok} is set to true.

    If \a base is 0, the C language convention is used: If the string
    begins with "0x", base 16 is used; if the string begins with "0",
    base 8 is used; otherwise, base 10 is used.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 77

    \sa number(), toInt()
*/

uint QString::toUInt(bool *ok, int base) const
{
    quint64 v = toULongLong(ok, base);
    if (v > UINT_MAX) {
        if (ok)
            *ok = false;
        v = 0;
    }
    return (uint)v;
}

/*!
    Returns the string converted to a \c short using base \a
    base, which is 10 by default and must be between 2 and 36, or 0.
    Returns 0 if the conversion fails.

    If a conversion error occurs, *\a{ok} is set to false; otherwise
    *\a{ok} is set to true.

    If \a base is 0, the C language convention is used: If the string
    begins with "0x", base 16 is used; if the string begins with "0",
    base 8 is used; otherwise, base 10 is used.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 76

    \sa number(), toUShort(), toInt()
*/

short QString::toShort(bool *ok, int base) const
{
    long v = toLongLong(ok, base);
    if (v < SHRT_MIN || v > SHRT_MAX) {
        if (ok)
            *ok = false;
        v = 0;
    }
    return (short)v;
}

/*!
    Returns the string converted to an \c{unsigned short} using base \a
    base, which is 10 by default and must be between 2 and 36, or 0.
    Returns 0 if the conversion fails.

    If a conversion error occurs, *\a{ok} is set to false; otherwise
    *\a{ok} is set to true.

    If \a base is 0, the C language convention is used: If the string
    begins with "0x", base 16 is used; if the string begins with "0",
    base 8 is used; otherwise, base 10 is used.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 80

    \sa number(), toShort()
*/

ushort QString::toUShort(bool *ok, int base) const
{
    ulong v = toULongLong(ok, base);
    if (v > USHRT_MAX) {
        if (ok)
            *ok = false;
        v = 0;
    }
    return (ushort)v;
}


/*!
    Returns the string converted to a \c double value.

    Returns 0.0 if the conversion fails.

    If a conversion error occurs, \c{*}\a{ok} is set to false;
    otherwise \c{*}\a{ok} is set to true.

    \snippet doc/src/snippets/qstring/main.cpp 66

    Various string formats for floating point numbers can be converted
    to double values:

    \snippet doc/src/snippets/qstring/main.cpp 67

    This function tries to interpret the string according to the
    current locale. The current locale is determined from the
    system at application startup and can be changed by calling
    QLocale::setDefault(). If the string cannot be interpreted
    according to the current locale, this function falls back
    on the "C" locale.

    \snippet doc/src/snippets/qstring/main.cpp 69
    \snippet doc/src/snippets/qstring/main.cpp 70

    Due to the ambiguity between the decimal point and thousands group
    separator in various locales, this function does not handle
    thousands group separators. If you need to convert such numbers,
    see QLocale::toDouble().

    \snippet doc/src/snippets/qstring/main.cpp 68

    \sa number() QLocale::setDefault() QLocale::toDouble() trimmed()
*/

double QString::toDouble(bool *ok) const
{
    bool my_ok;
    QLocale def_locale;
    double result = def_locale.d()->stringToDouble(*this, &my_ok, QLocalePrivate::FailOnGroupSeparators);
    if (my_ok) {
        if (ok != 0)
            *ok = true;
        return result;
    }

    QLocale c_locale(QLocale::C);
    return c_locale.d()->stringToDouble(*this, ok, QLocalePrivate::FailOnGroupSeparators);
}

/*!
    Returns the string converted to a \c float value.

    If a conversion error occurs, *\a{ok} is set to false; otherwise
    *\a{ok} is set to true. Returns 0.0 if the conversion fails.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 71

    \sa number(), toDouble(), toInt()
*/

#define QT_MAX_FLOAT 3.4028234663852886e+38

float QString::toFloat(bool *ok) const
{
    bool myOk;
    double d = toDouble(&myOk);
    if (!myOk || d > QT_MAX_FLOAT || d < -QT_MAX_FLOAT) {
        if (ok != 0)
            *ok = false;
        return 0.0;
    }
    if (ok != 0)
        *ok = true;
    return (float) d;
}

/*! \fn QString &QString::setNum(int n, int base)

    Sets the string to the printed value of \a n in the specified \a
    base, and returns a reference to the string.

    The base is 10 by default and must be between 2 and 36. For bases
    other than 10, \a n is treated as an unsigned integer.

    \snippet doc/src/snippets/qstring/main.cpp 56

   The formatting always uses QLocale::C, i.e., English/UnitedStates.
   To get a localized string representation of a number, use
   QLocale::toString() with the appropriate locale.
*/

/*! \fn QString &QString::setNum(uint n, int base)

    \overload
*/

/*! \fn QString &QString::setNum(long n, int base)

    \overload
*/

/*! \fn QString &QString::setNum(ulong n, int base)

    \overload
*/

/*!
    \overload
*/
QString &QString::setNum(qlonglong n, int base)
{
#if defined(QT_CHECK_RANGE)
    if (base < 2 || base > 36) {
        qWarning("QString::setNum: Invalid base (%d)", base);
        base = 10;
    }
#endif
    QLocale locale(QLocale::C);
    *this = locale.d()->longLongToString(n, -1, base);
    return *this;
}

/*!
    \overload
*/
QString &QString::setNum(qulonglong n, int base)
{
#if defined(QT_CHECK_RANGE)
    if (base < 2 || base > 36) {
        qWarning("QString::setNum: Invalid base (%d)", base);
        base = 10;
    }
#endif
    QLocale locale(QLocale::C);
    *this = locale.d()->unsLongLongToString(n, -1, base);
    return *this;
}

/*! \fn QString &QString::setNum(short n, int base)

    \overload
*/

/*! \fn QString &QString::setNum(ushort n, int base)

    \overload
*/

/*!
    \fn QString &QString::setNum(double n, char format, int precision)
    \overload

    Sets the string to the printed value of \a n, formatted according
    to the given \a format and \a precision, and returns a reference
    to the string.

    The \a format can be 'f', 'F', 'e', 'E', 'g' or 'G' (see the
    arg() function documentation for an explanation of the formats).

    Unlike QLocale::toString(), this function doesn't honor the
    user's locale settings.
*/

QString &QString::setNum(double n, char f, int prec)
{
    QLocalePrivate::DoubleForm form = QLocalePrivate::DFDecimal;
    uint flags = 0;

    if (qIsUpper(f))
        flags = QLocalePrivate::CapitalEorX;
    f = qToLower(f);

    switch (f) {
        case 'f':
            form = QLocalePrivate::DFDecimal;
            break;
        case 'e':
            form = QLocalePrivate::DFExponent;
            break;
        case 'g':
            form = QLocalePrivate::DFSignificantDigits;
            break;
        default:
#if defined(QT_CHECK_RANGE)
            qWarning("QString::setNum: Invalid format char '%c'", f);
#endif
            break;
    }

    QLocale locale(QLocale::C);
    *this = locale.d()->doubleToString(n, prec, form, -1, flags);
    return *this;
}

/*!
    \fn QString &QString::setNum(float n, char format, int precision)
    \overload

    Sets the string to the printed value of \a n, formatted according
    to the given \a format and \a precision, and returns a reference
    to the string.
*/


/*!
    \fn QString QString::number(long n, int base)

    Returns a string equivalent of the number \a n according to the
    specified \a base.

    The base is 10 by default and must be between 2
    and 36. For bases other than 10, \a n is treated as an
    unsigned integer.

    \snippet doc/src/snippets/qstring/main.cpp 35

    \sa setNum()
*/

QString QString::number(long n, int base)
{
    QString s;
    s.setNum(n, base);
    return s;
}

/*!
  \fn QString QString::number(ulong n, int base)

    \overload
*/
QString QString::number(ulong n, int base)
{
    QString s;
    s.setNum(n, base);
    return s;
}

/*!
    \overload
*/
QString QString::number(int n, int base)
{
    QString s;
    s.setNum(n, base);
    return s;
}

/*!
    \overload
*/
QString QString::number(uint n, int base)
{
    QString s;
    s.setNum(n, base);
    return s;
}

/*!
    \overload
*/
QString QString::number(qlonglong n, int base)
{
    QString s;
    s.setNum(n, base);
    return s;
}

/*!
    \overload
*/
QString QString::number(qulonglong n, int base)
{
    QString s;
    s.setNum(n, base);
    return s;
}


/*!
    \fn QString QString::number(double n, char format, int precision)

    Returns a string equivalent of the number \a n, formatted
    according to the specified \a format and \a precision. See
    \l{Argument Formats} for details.

    Unlike QLocale::toString(), this function does not honor the
    user's locale settings.

    \sa setNum(), QLocale::toString()
*/
QString QString::number(double n, char f, int prec)
{
    QString s;
    s.setNum(n, f, prec);
    return s;
}

/*!
    Splits the string into substrings wherever \a sep occurs, and
    returns the list of those strings. If \a sep does not match
    anywhere in the string, split() returns a single-element list
    containing this string.

    \a cs specifies whether \a sep should be matched case
    sensitively or case insensitively.

    If \a behavior is QString::SkipEmptyParts, empty entries don't
    appear in the result. By default, empty entries are kept.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 62

    \sa QStringList::join(), section()
*/
QStringList QString::split(const QString &sep, SplitBehavior behavior, Qt::CaseSensitivity cs) const
{
    QStringList list;
    int start = 0;
    int extra = 0;
    int end;
    while ((end = indexOf(sep, start + extra, cs)) != -1) {
        if (start != end || behavior == KeepEmptyParts)
            list.append(mid(start, end - start));
        start = end + sep.size();
        extra = (sep.size() == 0 ? 1 : 0);
    }
    if (start != size() || behavior == KeepEmptyParts)
        list.append(mid(start));
    return list;
}

/*!
    \overload
*/
QStringList QString::split(const QChar &sep, SplitBehavior behavior, Qt::CaseSensitivity cs) const
{
    QStringList list;
    int start = 0;
    int end;
    while ((end = indexOf(sep, start, cs)) != -1) {
        if (start != end || behavior == KeepEmptyParts)
            list.append(mid(start, end - start));
        start = end + 1;
    }
    if (start != size() || behavior == KeepEmptyParts)
        list.append(mid(start));
    return list;
}

#ifndef QT_NO_REGEXP
/*!
    \overload

    Splits the string into substrings wherever the regular expression
    \a rx matches, and returns the list of those strings. If \a rx
    does not match anywhere in the string, split() returns a
    single-element list containing this string.

    Here's an example where we extract the words in a sentence
    using one or more whitespace characters as the separator:

    \snippet doc/src/snippets/qstring/main.cpp 59

    Here's a similar example, but this time we use any sequence of
    non-word characters as the separator:

    \snippet doc/src/snippets/qstring/main.cpp 60

    Here's a third example where we use a zero-length assertion,
    \bold{\\b} (word boundary), to split the string into an
    alternating sequence of non-word and word tokens:

    \snippet doc/src/snippets/qstring/main.cpp 61

    \sa QStringList::join(), section()
*/
QStringList QString::split(const QRegExp &rx, SplitBehavior behavior) const
{
    QRegExp rx2(rx);
    QStringList list;
    int start = 0;
    int extra = 0;
    int end;
    while ((end = rx2.indexIn(*this, start + extra)) != -1) {
        int matchedLen = rx2.matchedLength();
        if (start != end || behavior == KeepEmptyParts)
            list.append(mid(start, end - start));
        start = end + matchedLen;
        extra = (matchedLen == 0) ? 1 : 0;
    }
    if (start != size() || behavior == KeepEmptyParts)
        list.append(mid(start));
    return list;
}
#endif

/*!
    \enum QString::NormalizationForm

    This enum describes the various normalized forms of Unicode text.

    \value NormalizationForm_D  Canonical Decomposition
    \value NormalizationForm_C  Canonical Decomposition followed by Canonical Composition
    \value NormalizationForm_KD  Compatibility Decomposition
    \value NormalizationForm_KC  Compatibility Decomposition followed by Canonical Composition

    \sa normalized(),
        {http://www.unicode.org/reports/tr15/}{Unicode Standard Annex #15}
*/

/*!
    \fn QString QString::normalized(NormalizationForm mode) const
    Returns the string in the given Unicode normalization \a mode.
*/
QString QString::normalized(QString::NormalizationForm mode) const
{
    return normalized(mode, UNICODE_DATA_VERSION);
}

/*!
    \since 4.5

    Returns a copy of this string repeated the specified number of \a times.

    If \a times is less than 1, an empty string is returned.

    Example:

    \code
        QString str("ab");
        str.repeated(4);            // returns "abababab"
    \endcode
*/
QString QString::repeated(int times) const
{
    if (d->size == 0)
        return *this;

    if (times <= 1) {
        if (times == 1)
            return *this;
        return QString();
    }

    const int resultSize = times * d->size;

    QString result;
    result.reserve(resultSize);
    if (result.d->alloc != resultSize)
        return QString(); // not enough memory

    memcpy(result.d->data, d->data, d->size * sizeof(ushort));

    int sizeSoFar = d->size;
    ushort *end = result.d->data + sizeSoFar;

    const int halfResultSize = resultSize >> 1;
    while (sizeSoFar <= halfResultSize) {
        memcpy(end, result.d->data, sizeSoFar * sizeof(ushort));
        end += sizeSoFar;
        sizeSoFar <<= 1;
    }
    memcpy(end, result.d->data, (resultSize - sizeSoFar) * sizeof(ushort));
    result.d->data[resultSize] = '\0';
    result.d->size = resultSize;
    return result;
}

void qt_string_normalize(QString *data, QString::NormalizationForm mode, QChar::UnicodeVersion version, int from);
/*!
    \overload
    \fn QString QString::normalized(NormalizationForm mode, QChar::UnicodeVersion version) const

    Returns the string in the given Unicode normalization \a mode,
    according to the given \a version of the Unicode standard.
*/
QString QString::normalized(QString::NormalizationForm mode, QChar::UnicodeVersion version) const
{
    QString copy = *this;
    qt_string_normalize(&copy, mode, version, 0);
    return copy;
}

void qt_string_normalize(QString *data, QString::NormalizationForm mode, QChar::UnicodeVersion version, int from)
{
    bool simple = true;
    const QChar *p = data->constData();
    int len = data->length();
    for (int i = from; i < len; ++i) {
        if (p[i].unicode() >= 0x80) {
            simple = false;
            break;
        }
    }
    if (simple)
        return;

    if (version == QChar::Unicode_Unassigned) {
        version = UNICODE_DATA_VERSION;
    } else if (version != UNICODE_DATA_VERSION) {
        const QString &s = *data;
        QChar *d = 0;
        for (int i = 0; i < NumNormalizationCorrections; ++i) {
            const NormalizationCorrection &n = uc_normalization_corrections[i];
            if (n.version > version) {
                int pos = from;
                if (QChar::requiresSurrogates(n.ucs4)) {
                    ushort ucs4High = QChar::highSurrogate(n.ucs4);
                    ushort ucs4Low = QChar::lowSurrogate(n.ucs4);
                    ushort oldHigh = QChar::highSurrogate(n.old_mapping);
                    ushort oldLow = QChar::lowSurrogate(n.old_mapping);
                    while (pos < s.length() - 1) {
                        if (s.at(pos).unicode() == ucs4High && s.at(pos + 1).unicode() == ucs4Low) {
                            if (!d)
                                d = data->data();
                            d[pos] = QChar(oldHigh);
                            d[++pos] = QChar(oldLow);
                        }
                        ++pos;
                    }
                } else {
                    while (pos < s.length()) {
                        if (s.at(pos).unicode() == n.ucs4) {
                            if (!d)
                                d = data->data();
                            d[pos] = QChar(n.old_mapping);
                        }
                        ++pos;
                    }
                }
            }
        }
    }
    decomposeHelper(data, mode < QString::NormalizationForm_KD, version, from);

    canonicalOrderHelper(data, version, from);

    if (mode == QString::NormalizationForm_D || mode == QString::NormalizationForm_KD)
        return;

    composeHelper(data, version, from);
}


struct ArgEscapeData
{
    int min_escape;            // lowest escape sequence number
    int occurrences;           // number of occurrences of the lowest escape sequence number
    int locale_occurrences;    // number of occurrences of the lowest escape sequence number that
                               // contain 'L'
    int escape_len;            // total length of escape sequences which will be replaced
};

static ArgEscapeData findArgEscapes(const QString &s)
{
    const QChar *uc_begin = s.unicode();
    const QChar *uc_end = uc_begin + s.length();

    ArgEscapeData d;

    d.min_escape = INT_MAX;
    d.occurrences = 0;
    d.escape_len = 0;
    d.locale_occurrences = 0;

    const QChar *c = uc_begin;
    while (c != uc_end) {
        while (c != uc_end && c->unicode() != '%')
            ++c;

        if (c == uc_end)
            break;
        const QChar *escape_start = c;
        if (++c == uc_end)
            break;

        bool locale_arg = false;
        if (c->unicode() == 'L') {
            locale_arg = true;
            if (++c == uc_end)
                break;
        }

        if (c->digitValue() == -1)
            continue;

        int escape = c->digitValue();
        ++c;

        if (c != uc_end && c->digitValue() != -1) {
            escape = (10 * escape) + c->digitValue();
            ++c;
        }

        if (escape > d.min_escape)
            continue;

        if (escape < d.min_escape) {
            d.min_escape = escape;
            d.occurrences = 0;
            d.escape_len = 0;
            d.locale_occurrences = 0;
        }

        ++d.occurrences;
        if (locale_arg)
            ++d.locale_occurrences;
        d.escape_len += c - escape_start;
    }
    return d;
}

static QString replaceArgEscapes(const QString &s, const ArgEscapeData &d, int field_width,
                                 const QString &arg, const QString &larg, const QChar &fillChar = QLatin1Char(' '))
{
    const QChar *uc_begin = s.unicode();
    const QChar *uc_end = uc_begin + s.length();

    int abs_field_width = qAbs(field_width);
    int result_len = s.length()
                     - d.escape_len
                     + (d.occurrences - d.locale_occurrences)
                     *qMax(abs_field_width, arg.length())
                     + d.locale_occurrences
                     *qMax(abs_field_width, larg.length());

    QString result(result_len, Qt::Uninitialized);
    QChar *result_buff = (QChar*) result.unicode();

    QChar *rc = result_buff;
    const QChar *c = uc_begin;
    int repl_cnt = 0;
    while (c != uc_end) {
        /* We don't have to check if we run off the end of the string with c,
           because as long as d.occurrences > 0 we KNOW there are valid escape
           sequences. */

        const QChar *text_start = c;

        while (c->unicode() != '%')
            ++c;

        const QChar *escape_start = c++;

        bool locale_arg = false;
        if (c->unicode() == 'L') {
            locale_arg = true;
            ++c;
        }

        int escape = c->digitValue();
        if (escape != -1) {
            if (c + 1 != uc_end && (c + 1)->digitValue() != -1) {
                escape = (10 * escape) + (c + 1)->digitValue();
                ++c;
            }
        }

        if (escape != d.min_escape) {
            memcpy(rc, text_start, (c - text_start)*sizeof(QChar));
            rc += c - text_start;
        }
        else {
            ++c;

            memcpy(rc, text_start, (escape_start - text_start)*sizeof(QChar));
            rc += escape_start - text_start;

            uint pad_chars;
            if (locale_arg)
                pad_chars = qMax(abs_field_width, larg.length()) - larg.length();
            else
                pad_chars = qMax(abs_field_width, arg.length()) - arg.length();

            if (field_width > 0) { // left padded
                for (uint i = 0; i < pad_chars; ++i)
                    (rc++)->unicode() = fillChar.unicode();
            }

            if (locale_arg) {
                memcpy(rc, larg.unicode(), larg.length()*sizeof(QChar));
                rc += larg.length();
            }
            else {
                memcpy(rc, arg.unicode(), arg.length()*sizeof(QChar));
                rc += arg.length();
            }

            if (field_width < 0) { // right padded
                for (uint i = 0; i < pad_chars; ++i)
                    (rc++)->unicode() = fillChar.unicode();
            }

            if (++repl_cnt == d.occurrences) {
                memcpy(rc, c, (uc_end - c)*sizeof(QChar));
                rc += uc_end - c;
                Q_ASSERT(rc - result_buff == result_len);
                c = uc_end;
            }
        }
    }
    Q_ASSERT(rc == result_buff + result_len);

    return result;
}

/*!
  Returns a copy of this string with the lowest numbered place marker
  replaced by string \a a, i.e., \c %1, \c %2, ..., \c %99.

  \a fieldWidth specifies the minimum amount of space that argument \a
  a shall occupy. If \a a requires less space than \a fieldWidth, it
  is padded to \a fieldWidth with character \a fillChar.  A positive
  \a fieldWidth produces right-aligned text. A negative \a fieldWidth
  produces left-aligned text.

  This example shows how we might create a \c status string for
  reporting progress while processing a list of files:

  \snippet doc/src/snippets/qstring/main.cpp 11

  First, \c arg(i) replaces \c %1. Then \c arg(total) replaces \c
  %2. Finally, \c arg(fileName) replaces \c %3.

  One advantage of using arg() over sprintf() is that the order of the
  numbered place markers can change, if the application's strings are
  translated into other languages, but each arg() will still replace
  the lowest numbered unreplaced place marker, no matter where it
  appears. Also, if place marker \c %i appears more than once in the
  string, the arg() replaces all of them.

  If there is no unreplaced place marker remaining, a warning message
  is output and the result is undefined. Place marker numbers must be
  in the range 1 to 99.
*/
QString QString::arg(const QString &a, int fieldWidth, const QChar &fillChar) const
{
    ArgEscapeData d = findArgEscapes(*this);

    if (d.occurrences == 0) {
        qWarning("QString::arg: Argument missing: %s, %s", toLocal8Bit().data(),
                  a.toLocal8Bit().data());
        return *this;
    }
    return replaceArgEscapes(*this, d, fieldWidth, a, a, fillChar);
}

/*!
  \fn QString QString::arg(const QString& a1, const QString& a2) const
  \overload arg()

  This is the same as \c {str.arg(a1).arg(a2)}, except that the
  strings \a a1 and \a a2 are replaced in one pass. This can make a
  difference if \a a1 contains e.g. \c{%1}:

  \snippet doc/src/snippets/qstring/main.cpp 13
*/

/*!
  \fn QString QString::arg(const QString& a1, const QString& a2, const QString& a3) const
  \overload arg()

  This is the same as calling \c str.arg(a1).arg(a2).arg(a3), except
  that the strings \a a1, \a a2 and \a a3 are replaced in one pass.
*/

/*!
  \fn QString QString::arg(const QString& a1, const QString& a2, const QString& a3, const QString& a4) const
  \overload arg()

  This is the same as calling \c
  {str.arg(a1).arg(a2).arg(a3).arg(a4)}, except that the strings \a
  a1, \a a2, \a a3 and \a a4 are replaced in one pass.
*/

/*!
  \fn QString QString::arg(const QString& a1, const QString& a2, const QString& a3, const QString& a4, const QString& a5) const
  \overload arg()

  This is the same as calling \c
  {str.arg(a1).arg(a2).arg(a3).arg(a4).arg(a5)}, except that the strings
  \a a1, \a a2, \a a3, \a a4, and \a a5 are replaced in one pass.
*/

/*!
  \fn QString QString::arg(const QString& a1, const QString& a2, const QString& a3, const QString& a4, const QString& a5, const QString& a6) const
  \overload arg()

  This is the same as calling \c
  {str.arg(a1).arg(a2).arg(a3).arg(a4).arg(a5).arg(a6))}, except that
  the strings \a a1, \a a2, \a a3, \a a4, \a a5, and \a a6 are
  replaced in one pass.
*/

/*!
  \fn QString QString::arg(const QString& a1, const QString& a2, const QString& a3, const QString& a4, const QString& a5, const QString& a6, const QString& a7) const
  \overload arg()

  This is the same as calling \c
  {str.arg(a1).arg(a2).arg(a3).arg(a4).arg(a5).arg(a6).arg(a7)},
  except that the strings \a a1, \a a2, \a a3, \a a4, \a a5, \a a6,
  and \a a7 are replaced in one pass.
*/

/*!
  \fn QString QString::arg(const QString& a1, const QString& a2, const QString& a3, const QString& a4, const QString& a5, const QString& a6, const QString& a7, const QString& a8) const
  \overload arg()

  This is the same as calling \c
  {str.arg(a1).arg(a2).arg(a3).arg(a4).arg(a5).arg(a6).arg(a7).arg(a8)},
  except that the strings \a a1, \a a2, \a a3, \a a4, \a a5, \a a6, \a
  a7, and \a a8 are replaced in one pass.
*/

/*!
  \fn QString QString::arg(const QString& a1, const QString& a2, const QString& a3, const QString& a4, const QString& a5, const QString& a6, const QString& a7, const QString& a8, const QString& a9) const
  \overload arg()

  This is the same as calling \c
  {str.arg(a1).arg(a2).arg(a3).arg(a4).arg(a5).arg(a6).arg(a7).arg(a8).arg(a9)},
  except that the strings \a a1, \a a2, \a a3, \a a4, \a a5, \a a6, \a
  a7, \a a8, and \a a9 are replaced in one pass.
*/

/*! \fn QString QString::arg(int a, int fieldWidth, int base, const QChar &fillChar) const
  \overload arg()

  The \a a argument is expressed in base \a base, which is 10 by
  default and must be between 2 and 36. For bases other than 10, \a a
  is treated as an unsigned integer.

  \a fieldWidth specifies the minimum amount of space that \a a is
  padded to and filled with the character \a fillChar. A positive
  value produces right-aligned text; a negative value produces
  left-aligned text.

  The '%' can be followed by an 'L', in which case the sequence is
  replaced with a localized representation of \a a. The conversion
  uses the default locale, set by QLocale::setDefault(). If no default
  locale was specified, the "C" locale is used. The 'L' flag is
  ignored if \a base is not 10.

  \snippet doc/src/snippets/qstring/main.cpp 12
  \snippet doc/src/snippets/qstring/main.cpp 14

  If \a fillChar is '0' (the number 0, ASCII 48), the locale's zero is
  used. For negative numbers, zero padding might appear before the
  minus sign.
*/

/*! \fn QString QString::arg(uint a, int fieldWidth, int base, const QChar &fillChar) const
  \overload arg()

  The \a base argument specifies the base to use when converting the
  integer \a a into a string. The base must be between 2 and 36.

  If \a fillChar is '0' (the number 0, ASCII 48), the locale's zero is
  used. For negative numbers, zero padding might appear before the
  minus sign.
*/

/*! \fn QString QString::arg(long a, int fieldWidth, int base, const QChar &fillChar) const
  \overload arg()

  \a fieldWidth specifies the minimum amount of space that \a a is
  padded to and filled with the character \a fillChar. A positive
  value produces right-aligned text; a negative value produces
  left-aligned text.

  The \a a argument is expressed in the given \a base, which is 10 by
  default and must be between 2 and 36.

  The '%' can be followed by an 'L', in which case the sequence is
  replaced with a localized representation of \a a. The conversion
  uses the default locale. The default locale is determined from the
  system's locale settings at application startup. It can be changed
  using QLocale::setDefault(). The 'L' flag is ignored if \a base is
  not 10.

  \snippet doc/src/snippets/qstring/main.cpp 12
  \snippet doc/src/snippets/qstring/main.cpp 14

  If \a fillChar is '0' (the number 0, ASCII 48), the locale's zero is
  used. For negative numbers, zero padding might appear before the
  minus sign.
*/

/*! \fn QString QString::arg(ulong a, int fieldWidth, int base, const QChar &fillChar) const
  \overload arg()

  \a fieldWidth specifies the minimum amount of space that \a a is
  padded to and filled with the character \a fillChar. A positive
  value produces right-aligned text; a negative value produces
  left-aligned text.

  The \a base argument specifies the base to use when converting the
  integer \a a to a string. The base must be between 2 and 36, with 8
  giving octal, 10 decimal, and 16 hexadecimal numbers.

  If \a fillChar is '0' (the number 0, ASCII 48), the locale's zero is
  used. For negative numbers, zero padding might appear before the
  minus sign.
*/

/*!
  \overload arg()

  \a fieldWidth specifies the minimum amount of space that \a a is
  padded to and filled with the character \a fillChar. A positive
  value produces right-aligned text; a negative value produces
  left-aligned text.

  The \a base argument specifies the base to use when converting the
  integer \a a into a string. The base must be between 2 and 36, with
  8 giving octal, 10 decimal, and 16 hexadecimal numbers.

  If \a fillChar is '0' (the number 0, ASCII 48), the locale's zero is
  used. For negative numbers, zero padding might appear before the
  minus sign.
*/
QString QString::arg(qlonglong a, int fieldWidth, int base, const QChar &fillChar) const
{
    ArgEscapeData d = findArgEscapes(*this);

    if (d.occurrences == 0) {
        qWarning() << "QString::arg: Argument missing:" << *this << ',' << a;
        return *this;
    }

    unsigned flags = QLocalePrivate::NoFlags;
    if (fillChar == QLatin1Char('0'))
        flags = QLocalePrivate::ZeroPadded;

    QString arg;
    if (d.occurrences > d.locale_occurrences)
        arg = QLocale::c().d()->longLongToString(a, -1, base, fieldWidth, flags);

    QString locale_arg;
    if (d.locale_occurrences > 0) {
        QLocale locale;
        if (!locale.numberOptions() & QLocale::OmitGroupSeparator)
            flags |= QLocalePrivate::ThousandsGroup;
        locale_arg = locale.d()->longLongToString(a, -1, base, fieldWidth, flags);
    }

    return replaceArgEscapes(*this, d, fieldWidth, arg, locale_arg, fillChar);
}

/*!
  \overload arg()

  \a fieldWidth specifies the minimum amount of space that \a a is
  padded to and filled with the character \a fillChar. A positive
  value produces right-aligned text; a negative value produces
  left-aligned text.

  The \a base argument specifies the base to use when converting the
  integer \a a into a string. \a base must be between 2 and 36, with 8
  giving octal, 10 decimal, and 16 hexadecimal numbers.

  If \a fillChar is '0' (the number 0, ASCII 48), the locale's zero is
  used. For negative numbers, zero padding might appear before the
  minus sign.
*/
QString QString::arg(qulonglong a, int fieldWidth, int base, const QChar &fillChar) const
{
    ArgEscapeData d = findArgEscapes(*this);

    if (d.occurrences == 0) {
        qWarning() << "QString::arg: Argument missing:" << *this << ',' << a;
        return *this;
    }

    unsigned flags = QLocalePrivate::NoFlags;
    if (fillChar == QLatin1Char('0'))
        flags = QLocalePrivate::ZeroPadded;

    QString arg;
    if (d.occurrences > d.locale_occurrences)
        arg = QLocale::c().d()->unsLongLongToString(a, -1, base, fieldWidth, flags);

    QString locale_arg;
    if (d.locale_occurrences > 0) {
        QLocale locale;
        if (!locale.numberOptions() & QLocale::OmitGroupSeparator)
            flags |= QLocalePrivate::ThousandsGroup;
        locale_arg = locale.d()->unsLongLongToString(a, -1, base, fieldWidth, flags);
    }

    return replaceArgEscapes(*this, d, fieldWidth, arg, locale_arg, fillChar);
}

/*!
  \overload arg()

  \fn QString QString::arg(short a, int fieldWidth, int base, const QChar &fillChar) const

  \a fieldWidth specifies the minimum amount of space that \a a is
  padded to and filled with the character \a fillChar. A positive
  value produces right-aligned text; a negative value produces
  left-aligned text.

  The \a base argument specifies the base to use when converting the
  integer \a a into a string. The base must be between 2 and 36, with
  8 giving octal, 10 decimal, and 16 hexadecimal numbers.

  If \a fillChar is '0' (the number 0, ASCII 48), the locale's zero is
  used. For negative numbers, zero padding might appear before the
  minus sign.
*/

/*!
  \fn QString QString::arg(ushort a, int fieldWidth, int base, const QChar &fillChar) const
  \overload arg()

  \a fieldWidth specifies the minimum amount of space that \a a is
  padded to and filled with the character \a fillChar. A positive
  value produces right-aligned text; a negative value produces
  left-aligned text.

  The \a base argument specifies the base to use when converting the
  integer \a a into a string. The base must be between 2 and 36, with
  8 giving octal, 10 decimal, and 16 hexadecimal numbers.

  If \a fillChar is '0' (the number 0, ASCII 48), the locale's zero is
  used. For negative numbers, zero padding might appear before the
  minus sign.
*/

/*!
    \overload arg()
*/
QString QString::arg(QChar a, int fieldWidth, const QChar &fillChar) const
{
    QString c;
    c += a;
    return arg(c, fieldWidth, fillChar);
}

/*!
  \overload arg()

  The \a a argument is interpreted as a Latin-1 character.
*/
QString QString::arg(char a, int fieldWidth, const QChar &fillChar) const
{
    QString c;
    c += QLatin1Char(a);
    return arg(c, fieldWidth, fillChar);
}

/*!
  \fn QString QString::arg(double a, int fieldWidth, char format, int precision, const QChar &fillChar) const
  \overload arg()

  Argument \a a is formatted according to the specified \a format and
  \a precision. See \l{Argument Formats} for details.

  \a fieldWidth specifies the minimum amount of space that \a a is
  padded to and filled with the character \a fillChar.  A positive
  value produces right-aligned text; a negative value produces
  left-aligned text.

  \snippet doc/src/snippets/code/src_corelib_tools_qstring.cpp 2

  The '%' can be followed by an 'L', in which case the sequence is
  replaced with a localized representation of \a a. The conversion
  uses the default locale, set by QLocale::setDefaultLocale(). If no
  default locale was specified, the "C" locale is used.

  If \a fillChar is '0' (the number 0, ASCII 48), this function will
  use the locale's zero to pad. For negative numbers, the zero padding
  will probably appear before the minus sign.

  \sa QLocale::toString()
*/
QString QString::arg(double a, int fieldWidth, char fmt, int prec, const QChar &fillChar) const
{
    ArgEscapeData d = findArgEscapes(*this);

    if (d.occurrences == 0) {
        qWarning("QString::arg: Argument missing: %s, %g", toLocal8Bit().data(), a);
        return *this;
    }

    unsigned flags = QLocalePrivate::NoFlags;
    if (fillChar == QLatin1Char('0'))
        flags = QLocalePrivate::ZeroPadded;

    if (qIsUpper(fmt))
        flags |= QLocalePrivate::CapitalEorX;
    fmt = qToLower(fmt);

    QLocalePrivate::DoubleForm form = QLocalePrivate::DFDecimal;
    switch (fmt) {
    case 'f':
        form = QLocalePrivate::DFDecimal;
        break;
    case 'e':
        form = QLocalePrivate::DFExponent;
        break;
    case 'g':
        form = QLocalePrivate::DFSignificantDigits;
        break;
    default:
#if defined(QT_CHECK_RANGE)
        qWarning("QString::arg: Invalid format char '%c'", fmt);
#endif
        break;
    }

    QString arg;
    if (d.occurrences > d.locale_occurrences)
        arg = QLocale::c().d()->doubleToString(a, prec, form, fieldWidth, flags);

    QString locale_arg;
    if (d.locale_occurrences > 0) {
        QLocale locale;

        if (!locale.numberOptions() & QLocale::OmitGroupSeparator)
            flags |= QLocalePrivate::ThousandsGroup;
        locale_arg = locale.d()->doubleToString(a, prec, form, fieldWidth, flags);
    }

    return replaceArgEscapes(*this, d, fieldWidth, arg, locale_arg, fillChar);
}

static int getEscape(const QChar *uc, int *pos, int len, int maxNumber = 999)
{
    int i = *pos;
    ++i;
    if (i < len && uc[i] == QLatin1Char('L'))
        ++i;
    if (i < len) {
        int escape = uc[i].unicode() - '0';
        if (uint(escape) >= 10U)
            return -1;
        ++i;
        while (i < len) {
            int digit = uc[i].unicode() - '0';
            if (uint(digit) >= 10U)
                break;
            escape = (escape * 10) + digit;
            ++i;
        }
        if (escape <= maxNumber) {
            *pos = i;
            return escape;
        }
    }
    return -1;
}

QString QString::multiArg(int numArgs, const QString **args) const
{
    QString result;
    QMap<int, int> numbersUsed;
    const QChar *uc = (const QChar *) d->data;
    const int len = d->size;
    const int end = len - 1;
    int lastNumber = -1;
    int i = 0;

    // populate the numbersUsed map with the %n's that actually occur in the string
    while (i < end) {
        if (uc[i] == QLatin1Char('%')) {
            int number = getEscape(uc, &i, len);
            if (number != -1) {
                numbersUsed.insert(number, -1);
                continue;
            }
        }
        ++i;
    }

    // assign an argument number to each of the %n's
    QMap<int, int>::iterator j = numbersUsed.begin();
    QMap<int, int>::iterator jend = numbersUsed.end();
    int arg = 0;
    while (j != jend && arg < numArgs) {
        *j = arg++;
        lastNumber = j.key();
        ++j;
    }

    // sanity
    if (numArgs > arg) {
        qWarning("QString::arg: %d argument(s) missing in %s", numArgs - arg, toLocal8Bit().data());
        numArgs = arg;
    }

    i = 0;
    while (i < len) {
        if (uc[i] == QLatin1Char('%') && i != end) {
            int number = getEscape(uc, &i, len, lastNumber);
            int arg = numbersUsed[number];
            if (number != -1 && arg != -1) {
                result += *args[arg];
                continue;
            }
        }
        result += uc[i++];
    }
    return result;
}

static bool isStringRightToLeft(const ushort *p, const ushort *end)
{
    bool righttoleft = false;
    while (p < end) {
        switch(QChar::direction(*p))
        {
        case QChar::DirL:
            goto end;
        case QChar::DirR:
        case QChar::DirAL:
            righttoleft = true;
            goto end;
        default:
            break;
        }
        ++p;
    }
 end:
    return righttoleft;
}

/*! \internal
 */
void QString::updateProperties() const
{
    ushort *p = d->data;
    ushort *end = p + d->size;
    d->simpletext = true;
    while (p < end) {
        ushort uc = *p;
        // sort out regions of complex text formatting
        if (uc > 0x058f && (uc < 0x1100 || uc > 0xfb0f)) {
            d->simpletext = false;
        }
        p++;
    }

    d->righttoleft = isStringRightToLeft(d->data, d->data + d->size);
    d->clean = true;
}

bool QString::isRightToLeft() const
{
    return isStringRightToLeft(d->data, d->data + d->size);
}

/*! \fn bool QString::isSimpleText() const

    \internal
*/

/*! \fn bool QString::isRightToLeft() const

    Returns true if the string is read right to left.
*/


/*! \fn QChar *QString::data()

    Returns a pointer to the data stored in the QString. The pointer
    can be used to access and modify the characters that compose the
    string. For convenience, the data is '\\0'-terminated.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp 19

    Note that the pointer remains valid only as long as the string is
    not modified by other means. For read-only access, constData() is
    faster because it never causes a \l{deep copy} to occur.

    \sa constData(), operator[]()
*/

/*! \fn const QChar *QString::data() const

    \overload
*/

/*! \fn const QChar *QString::constData() const

    Returns a pointer to the data stored in the QString. The pointer
    can be used to access the characters that compose the string. For
    convenience, the data is '\\0'-terminated.

    Note that the pointer remains valid only as long as the string is
    not modified.

    \sa data(), operator[]()
*/

/*! \fn void QString::push_front(const QString &other)

    This function is provided for STL compatibility, prepending the
    given \a other string to the beginning of this string. It is
    equivalent to \c prepend(other).

    \sa prepend()
*/

/*! \fn void QString::push_front(QChar ch)

    \overload

    Prepends the given \a ch character to the beginning of this string.
*/

/*! \fn void QString::push_back(const QString &other)

    This function is provided for STL compatibility, appending the
    given \a other string onto the end of this string. It is
    equivalent to \c append(other).

    \sa append()
*/

/*! \fn void QString::push_back(QChar ch)

    \overload

    Appends the given \a ch character onto the end of this string.
*/

/*!
    \fn std::string QString::toStdString() const

    Returns a std::string object with the data contained in this
    QString. The Unicode data is converted into 8-bit characters using
    the toAscii() function.

    This operator is mostly useful to pass a QString to a function
    that accepts a std::string object.

    If the QString contains Unicode characters that the
    QTextCodec::codecForCStrings() codec cannot handle, using this operator
    can lead to loss of information.

    This operator is only available if Qt is configured with STL
    compatibility enabled.

    \sa toAscii(), toLatin1(), toUtf8(), toLocal8Bit()
*/

/*!
    Constructs a QString that uses the first \a size Unicode characters
    in the array \a unicode. The data in \a unicode is \e not
    copied. The caller must be able to guarantee that \a unicode will
    not be deleted or modified as long as the QString (or an
    unmodified copy of it) exists.

    Any attempts to modify the QString or copies of it will cause it
    to create a deep copy of the data, ensuring that the raw data
    isn't modified.

    Here's an example of how we can use a QRegExp on raw data in
    memory without requiring to copy the data into a QString:

    \snippet doc/src/snippets/qstring/main.cpp 22
    \snippet doc/src/snippets/qstring/main.cpp 23

    \warning A string created with fromRawData() is \e not
    '\\0'-terminated, unless the raw data contains a '\\0' character
    at position \a size. This means unicode() will \e not return a
    '\\0'-terminated string (although utf16() does, at the cost of
    copying the raw data).

    \sa fromUtf16(), setRawData()
*/
QString QString::fromRawData(const QChar *unicode, int size)
{
    Data *x = static_cast<Data *>(qMalloc(sizeof(Data)));
    Q_CHECK_PTR(x);
    if (unicode) {
        x->data = (ushort *)unicode;
    } else {
        x->data = x->array;
        size = 0;
    }
    x->ref = 1;
    x->alloc = x->size = size;
    *x->array = '\0';
    x->clean = x->asciiCache = x->simpletext = x->righttoleft = x->capacity = 0;
    return QString(x, 0);
}

/*!
    \since 4.7

    Resets the QString to use the first \a size Unicode characters
    in the array \a unicode. The data in \a unicode is \e not
    copied. The caller must be able to guarantee that \a unicode will
    not be deleted or modified as long as the QString (or an
    unmodified copy of it) exists.

    This function can be used instead of fromRawData() to re-use
    existings QString objects to save memory re-allocations.

    \sa fromRawData()
*/
QString &QString::setRawData(const QChar *unicode, int size)
{
    if (d->ref != 1 || (d->data == d->array && d->alloc)) {
        *this = fromRawData(unicode, size);
    } else {
#ifdef QT3_SUPPORT
        if (d->asciiCache) {
            Q_ASSERT(asciiCache);
            asciiCache->remove(d);
        }
#endif
        if (unicode) {
            d->data = (ushort *)unicode;
        } else {
            d->data = d->array;
            size = 0;
        }
        d->alloc = d->size = size;
        *d->array = '\0';
        d->clean = d->asciiCache = d->simpletext = d->righttoleft = d->capacity = 0;
    }
    return *this;
}

/*! \class QLatin1String
    \brief The QLatin1String class provides a thin wrapper around an US-ASCII/Latin-1 encoded string literal.

    \ingroup string-processing
    \reentrant

    Many of QString's member functions are overloaded to accept
    \c{const char *} instead of QString. This includes the copy
    constructor, the assignment operator, the comparison operators,
    and various other functions such as \link QString::insert()
    insert() \endlink, \link QString::replace() replace()\endlink,
    and \link QString::indexOf() indexOf()\endlink. These functions
    are usually optimized to avoid constructing a QString object for
    the \c{const char *} data. For example, assuming \c str is a
    QString,

    \snippet doc/src/snippets/code/src_corelib_tools_qstring.cpp 3

    is much faster than

    \snippet doc/src/snippets/code/src_corelib_tools_qstring.cpp 4

    because it doesn't construct four temporary QString objects and
    make a deep copy of the character data.

    Applications that define \c QT_NO_CAST_FROM_ASCII (as explained
    in the QString documentation) don't have access to QString's
    \c{const char *} API. To provide an efficient way of specifying
    constant Latin-1 strings, Qt provides the QLatin1String, which is
    just a very thin wrapper around a \c{const char *}. Using
    QLatin1String, the example code above becomes

    \snippet doc/src/snippets/code/src_corelib_tools_qstring.cpp 5

    This is a bit longer to type, but it provides exactly the same
    benefits as the first version of the code, and is faster than
    converting the Latin-1 strings using QString::fromLatin1().

    Thanks to the QString(const QLatin1String &) constructor,
    QLatin1String can be used everywhere a QString is expected. For
    example:

    \snippet doc/src/snippets/code/src_corelib_tools_qstring.cpp 6

    \sa QString, QLatin1Char
*/

/*! \fn QLatin1String::QLatin1String(const char *str)

    Constructs a QLatin1String object that stores \a str. Note that if
    \a str is 0, an empty string is created; this case is handled by
    QString.

    The string data is \e not copied. The caller must be able to
    guarantee that \a str will not be deleted or modified as long as
    the QLatin1String object exists.

    \sa latin1()
*/

/*!
    \since 4.1
    \fn QLatin1String &QLatin1String::operator=(const QLatin1String &other)

    Constructs a copy of \a other.
*/

/*! \fn const char *QLatin1String::latin1() const

    Returns the Latin-1 string stored in this object.
*/

/*! \fn bool QLatin1String::operator==(const QString &other) const

    Returns true if this string is equal to string \a other;
    otherwise returns false.

    The comparison is based exclusively on the numeric Unicode values
    of the characters and is very fast, but is not what a human would
    expect. Consider sorting user-interface strings with
    QString::localeAwareCompare().
*/

/*!
    \fn bool QLatin1String::operator==(const char *other) const
    \since 4.3
    \overload

    The \a other const char pointer is converted to a QString using
    the QString::fromAscii() function.

    You can disable this operator by defining \c
    QT_NO_CAST_FROM_ASCII when you compile your applications. This
    can be useful if you want to ensure that all user-visible strings
    go through QObject::tr(), for example.
*/

/*! \fn bool QLatin1String::operator!=(const QString &other) const

    Returns true if this string is not equal to string \a other;
    otherwise returns false.

    The comparison is based exclusively on the numeric Unicode values
    of the characters and is very fast, but is not what a human would
    expect. Consider sorting user-interface strings with
    QString::localeAwareCompare().
*/

/*!
    \fn bool QLatin1String::operator!=(const char *other) const
    \since 4.3
    \overload operator!=()

    The \a other const char pointer is converted to a QString using
    the QString::fromAscii() function.

    You can disable this operator by defining \c
    QT_NO_CAST_FROM_ASCII when you compile your applications. This
    can be useful if you want to ensure that all user-visible strings
    go through QObject::tr(), for example.
*/

/*!
    \fn bool QLatin1String::operator>(const QString &other) const

    Returns true if this string is lexically greater than string \a
    other; otherwise returns false.

    The comparison is based exclusively on the numeric Unicode values
    of the characters and is very fast, but is not what a human would
    expect. Consider sorting user-interface strings with
    QString::localeAwareCompare().
*/

/*!
    \fn bool QLatin1String::operator>(const char *other) const
    \since 4.3
    \overload

    The \a other const char pointer is converted to a QString using
    the QString::fromAscii() function.

    You can disable this operator by defining \c QT_NO_CAST_FROM_ASCII
    when you compile your applications. This can be useful if you want
    to ensure that all user-visible strings go through QObject::tr(),
    for example.
*/

/*!
    \fn bool QLatin1String::operator<(const QString &other) const

    Returns true if this string is lexically less than the \a other
    string; otherwise returns false.

    The comparison is based exclusively on the numeric Unicode values
    of the characters and is very fast, but is not what a human would
    expect. Consider sorting user-interface strings using the
    QString::localeAwareCompare() function.
*/

/*!
    \fn bool QLatin1String::operator<(const char *other) const
    \since 4.3
    \overload

    The \a other const char pointer is converted to a QString using
    the QString::fromAscii() function.

    You can disable this operator by defining \c
    QT_NO_CAST_FROM_ASCII when you compile your applications. This
    can be useful if you want to ensure that all user-visible strings
    go through QObject::tr(), for example.
*/

/*!
    \fn bool QLatin1String::operator>=(const QString &other) const

    Returns true if this string is lexically greater than or equal
    to string \a other; otherwise returns false.

    The comparison is based exclusively on the numeric Unicode values
    of the characters and is very fast, but is not what a human would
    expect. Consider sorting user-interface strings with
    QString::localeAwareCompare().
*/

/*!
    \fn bool QLatin1String::operator>=(const char *other) const
    \since 4.3
    \overload

    The \a other const char pointer is converted to a QString using
    the QString::fromAscii() function.

    You can disable this operator by defining \c
    QT_NO_CAST_FROM_ASCII when you compile your applications. This
    can be useful if you want to ensure that all user-visible strings
    go through QObject::tr(), for example.
*/

/*! \fn bool QLatin1String::operator<=(const QString &other) const

    Returns true if this string is lexically less than or equal
    to string \a other; otherwise returns false.

    The comparison is based exclusively on the numeric Unicode values
    of the characters and is very fast, but is not what a human would
    expect. Consider sorting user-interface strings with
    QString::localeAwareCompare().
*/

/*!
    \fn bool QLatin1String::operator<=(const char *other) const
    \since 4.3
    \overload

    The \a other const char pointer is converted to a QString using
    the QString::fromAscii() function.

    You can disable this operator by defining \c
    QT_NO_CAST_FROM_ASCII when you compile your applications. This
    can be useful if you want to ensure that all user-visible strings
    go through QObject::tr(), for example.
*/



/* \fn bool operator==(const QLatin1String &s1, const QLatin1String &s2)
   \relates QLatin1String

   Returns true if string \a s1 is lexically equal to string \a s2; otherwise
   returns false.
*/
/* \fn bool operator!=(const QLatin1String &s1, const QLatin1String &s2)
   \relates QLatin1String

   Returns true if string \a s1 is lexically unequal to string \a s2; otherwise
   returns false.
*/
/* \fn bool operator<(const QLatin1String &s1, const QLatin1String &s2)
   \relates QLatin1String

   Returns true if string \a s1 is lexically smaller than string \a s2; otherwise
   returns false.
*/
/* \fn bool operator<=(const QLatin1String &s1, const QLatin1String &s2)
   \relates QLatin1String

   Returns true if string \a s1 is lexically smaller than or equal to string \a s2; otherwise
   returns false.
*/
/* \fn bool operator>(const QLatin1String &s1, const QLatin1String &s2)
   \relates QLatin1String

   Returns true if string \a s1 is lexically greater than string \a s2; otherwise
   returns false.
*/
/* \fn bool operator>=(const QLatin1String &s1, const QLatin1String &s2)
   \relates QLatin1String

   Returns true if string \a s1 is lexically greater than or equal to
   string \a s2; otherwise returns false.
*/


#if !defined(QT_NO_DATASTREAM) || (defined(QT_BOOTSTRAPPED) && !defined(QT_BUILD_QMAKE))
/*!
    \fn QDataStream &operator<<(QDataStream &stream, const QString &string)
    \relates QString

    Writes the given \a string to the specified \a stream.

    \sa {Serializing Qt Data Types}
*/

QDataStream &operator<<(QDataStream &out, const QString &str)
{
    if (out.version() == 1) {
        out << str.toLatin1();
    } else {
        if (!str.isNull() || out.version() < 3) {
            if ((out.byteOrder() == QDataStream::BigEndian) == (QSysInfo::ByteOrder == QSysInfo::BigEndian)) {
                out.writeBytes(reinterpret_cast<const char *>(str.unicode()), sizeof(QChar) * str.length());
            } else {
                QVarLengthArray<ushort> buffer(str.length());
                const ushort *data = reinterpret_cast<const ushort *>(str.constData());
                for (int i = 0; i < str.length(); i++) {
                    buffer[i] = qbswap(*data);
                    ++data;
                }
                out.writeBytes(reinterpret_cast<const char *>(buffer.data()), sizeof(ushort) * buffer.size());
            }
        } else {
            // write null marker
            out << (quint32)0xffffffff;
        }
    }
    return out;
}

/*!
    \fn QDataStream &operator>>(QDataStream &stream, QString &string)
    \relates QString

    Reads a string from the specified \a stream into the given \a string.

    \sa {Serializing Qt Data Types}
*/

QDataStream &operator>>(QDataStream &in, QString &str)
{
#ifdef QT_QSTRING_UCS_4
#if defined(Q_CC_GNU)
#warning "operator>> not working properly"
#endif
#endif

    if (in.version() == 1) {
        QByteArray l;
        in >> l;
        str = QString::fromLatin1(l);
    } else {
        quint32 bytes = 0;
        in >> bytes;                                  // read size of string
        if (bytes == 0xffffffff) {                    // null string
            str.clear();
        } else if (bytes > 0) {                       // not empty
            if (bytes & 0x1) {
                str.clear();
                in.setStatus(QDataStream::ReadCorruptData);
                return in;
            }

            const quint32 Step = 1024 * 1024;
            quint32 len = bytes / 2;
            quint32 allocated = 0;

            while (allocated < len) {
                int blockSize = qMin(Step, len - allocated);
                str.resize(allocated + blockSize);
                if (in.readRawData(reinterpret_cast<char *>(str.data()) + allocated * 2,
                                   blockSize * 2) != blockSize * 2) {
                    str.clear();
                    in.setStatus(QDataStream::ReadPastEnd);
                    return in;
                }
                allocated += blockSize;
            }

            if ((in.byteOrder() == QDataStream::BigEndian)
                    != (QSysInfo::ByteOrder == QSysInfo::BigEndian)) {
                ushort *data = reinterpret_cast<ushort *>(str.data());
                while (len--) {
                    *data = qbswap(*data);
                    ++data;
                }
            }
        } else {
            str = QLatin1String("");
        }
    }
    return in;
}
#endif // QT_NO_DATASTREAM

/*!
    \fn void QString::setLength(int nl)

    Use resize() instead.
*/

/*!
    \fn QString QString::copy() const

    Use simple assignment instead. QString is implicitly shared so if
    a copy is modified only the copy is changed.
*/

/*!
    \fn QString &QString::remove(QChar c, bool cs)

    Use the remove(QChar, Qt::CaseSensitive) overload instead.
*/

/*!
    \fn QString &QString::remove(const QString  &s, bool cs)

    Use the remove(QString, Qt::CaseSensitive) overload instead.
*/

/*!
    \fn QString &QString::replace(QChar c, const QString  &after, bool cs)

    Use the replace(QChar, QString, Qt::CaseSensitive) overload instead.
*/

/*!
    \fn QString &QString::replace(const QString &before, const QString &after, bool cs)

    Use the replace(QString, QString, Qt::CaseSensitive) overload instead.
*/

/*!
    \fn QString &QString::replace(char c, const QString &after, bool cs)

    Use the replace(QChar, QString, Qt::CaseSensitive) overload instead.
*/

/*!
    \fn QString &QString::replace(char c, const QString &after, Qt::CaseSensitivity cs)

    Use the replace(QChar, QString, Qt::CaseSensitive) overload instead.
*/

/*!
    \fn int QString::find(QChar c, int i = 0, bool cs = true) const

    Use indexOf() instead.
*/

/*!
    \fn int QString::find(const QString &s, int i = 0, bool cs = true) const

    Use indexOf() instead.
*/

/*!
    \fn int QString::findRev(QChar c, int i = -1, bool cs = true) const

    Use lastIndexOf() instead.
*/

/*!
    \fn int QString::findRev(const QString &s, int i = -1, bool cs = true) const

    Use lastIndexOf() instead.
*/

/*!
    \fn int QString::find(const QRegExp &rx, int i=0) const

    Use indexOf() instead.
*/

/*!
    \fn int QString::find(QRegExp &rx, int i=0) const
    \internal
    \since 4.5

    Use indexOf() instead.
*/

/*!
    \fn int QString::findRev(const QRegExp &rx, int i=-1) const

    Use lastIndexOf() instead.
*/

/*!
    \fn int QString::findRev(QRegExp &rx, int i=0) const
    \internal
    \since 4.5

    Use lastIndexOf() instead.
*/

/*!
    \fn QBool QString::contains(QChar c, bool cs) const

    Use the contains(QChar, Qt::CaseSensitive) overload instead.
*/

/*!
    \fn QBool QString::contains(const QString &s, bool cs) const

    Use the contains(QString, Qt::CaseSensitive) overload instead.
*/

/*!
    \fn bool QString::startsWith(const QString &s, bool cs) const

    Use the startsWith(QString, Qt::CaseSensitive) overload instead.
*/


/*!
    \fn bool QString::endsWith(const QString &s, bool cs) const

    Use the endsWith(QString, Qt::CaseSensitive) overload instead.
*/

/*!
    \fn QString QString::leftJustify(int width, QChar fill = QLatin1Char(' '), bool trunc=false) const

    Use leftJustified() instead.
*/

/*!
    \fn QString QString::rightJustify(int width, QChar fill = QLatin1Char(' '), bool trunc=false) const

    Use rightJustified() instead.
*/

/*!
    \fn QString QString::lower() const

    Use toLower() instead.
*/

/*!
    \fn QString QString::upper() const

    Use toUpper() instead.
*/

/*!
    \fn QString QString::stripWhiteSpace() const

    Use trimmed() instead.
*/

/*!
    \fn QString QString::simplifyWhiteSpace() const

    Use simplified() instead.
*/

/*!
    \fn QString &QString::setUnicodeCodes(const ushort *unicode_as_ushorts, int size)

    Use setUtf16() instead.
*/

/*!
    \fn ushort *QString::ucs2() const

    Use utf16() instead.
*/

/*!
    \fn QString QString::fromUcs2(const ushort *unicode, int size = -1)

    Use fromUtf16() instead.
*/

/*!
    \fn QString &QString::setAscii(const char *str, int len = -1)

    Use fromAscii() instead.
*/

/*!
    \fn QString &QString::setLatin1(const char *str, int len = -1)

    Use fromLatin1() instead.
*/

/*!
    \fn QChar QString::constref(uint i) const

    Use at() instead.
*/

/*!
    \fn QChar &QString::ref(uint i);

    Use operator[]() instead.
*/

/*!
    \fn QString::operator const char *() const

    Use toAscii().constData() instead.
*/

/*!
    \class QConstString
    \brief The QConstString class is a wrapper for constant Unicode string data.
    \compat

    In Qt 4, QConstString is replaced by QString::fromRawData(), a
    static function that constructs a QString object based on Unicode
    string data.

    Because QString::fromRawData() has slightly more stringent
    constraints than QConstString had in Qt 3, the new QConstString
    class takes a deep copy of the string data.

    \sa QString::fromRawData()
*/

/*!
    \fn QConstString::QConstString(const QChar *unicode, int size)

    Use QString(\a unicode, \a size) or
    QString::fromRawData(\a unicode, \a size) instead.
*/

/*!
    \fn const QString &QConstString::string() const

    Returns \c *this. Not necessary in Qt 4.
*/



/*!
    \class QStringRef
    \since 4.3
    \brief The QStringRef class provides a thin wrapper around QString substrings.
    \reentrant
    \ingroup tools
    \ingroup string-processing

    QStringRef provides a read-only subset of the QString API.

    A string reference explicitly references a portion of a string()
    with a given size(), starting at a specific position(). Calling
    toString() returns a copy of the data as a real QString instance.

    This class is designed to improve the performance of substring
    handling when manipulating substrings obtained from existing QString
    instances. QStringRef avoids the memory allocation and reference
    counting overhead of a standard QString by simply referencing a
    part of the original string. This can prove to be advantageous in
    low level code, such as that used in a parser, at the expense of
    potentially more complex code.

    For most users, there are no semantic benefits to using QStringRef
    instead of QString since QStringRef requires attention to be paid
    to memory management issues, potentially making code more complex
    to write and maintain.

    \warning A QStringRef is only valid as long as the referenced
    string exists. If the original string is deleted, the string
    reference points to an invalid memory location.

    We suggest that you only use this class in stable code where profiling
    has clearly identified that performance improvements can be made by
    replacing standard string operations with the optimized substring
    handling provided by this class.

    \sa {Implicitly Shared Classes}
*/


/*!
 \fn QStringRef::QStringRef()

 Constructs an empty string reference.
*/

/*! \fn QStringRef::QStringRef(const QString *string, int position, int length)

Constructs a string reference to the range of characters in the given
\a string specified by the starting \a position and \a length in characters.

\warning This function exists to improve performance as much as possible,
and performs no bounds checking. For program correctness, \a position and
\a length must describe a valid substring of \a string.

This means that the starting \a position must be positive or 0 and smaller
than \a string's length, and \a length must be positive or 0 but smaller than
the string's length minus the starting \a position;
i.e, 0 <= position < string->length() and
0 <= length <= string->length() - position must both be satisfied.
*/

/*! \fn QStringRef::QStringRef(const QString *string)

Constructs a string reference to the given \a string.
*/

/*! \fn QStringRef::QStringRef(const QStringRef &other)

Constructs a copy of the \a other string reference.
 */
/*!
\fn QStringRef::~QStringRef()

Destroys the string reference.

Since this class is only used to refer to string data, and does not take
ownership of it, no memory is freed when instances are destroyed.
*/


/*!
    \fn int QStringRef::position() const

    Returns the starting position in the referenced string that is referred to
    by the string reference.

    \sa size(), string()
*/

/*!
    \fn int QStringRef::size() const

    Returns the number of characters referred to by the string reference.
    Equivalent to length() and count().

    \sa position(), string()
*/
/*!
    \fn int QStringRef::count() const
    Returns the number of characters referred to by the string reference.
    Equivalent to size() and length().

    \sa position(), string()
*/
/*!
    \fn int QStringRef::length() const
    Returns the number of characters referred to by the string reference.
    Equivalent to size() and count().

    \sa position(), string()
*/


/*!
    \fn bool QStringRef::isEmpty() const

    Returns true if the string reference has no characters; otherwise returns
    false.

    A string reference is empty if its size is zero.

    \sa size()
*/

/*!
    \fn bool QStringRef::isNull() const

    Returns true if string() returns a null pointer or a pointer to a
    null string; otherwise returns true.

    \sa size()
*/

/*!
    \fn const QString *QStringRef::string() const

    Returns a pointer to the string referred to by the string reference, or
    0 if it does not reference a string.

    \sa unicode()
*/


/*!
    \fn const QChar *QStringRef::unicode() const

    Returns a Unicode representation of the string reference. Since
    the data stems directly from the referenced string, it is not
    null-terminated unless the string reference includes the string's
    null terminator.

    \sa string()
*/

/*!
    \fn const QChar *QStringRef::data() const

    Same as unicode().
*/

/*!
    \fn const QChar *QStringRef::constData() const

    Same as unicode().
*/

/*!
    Returns a copy of the string reference as a QString object.

    If the string reference is not a complete reference of the string
    (meaning that position() is 0 and size() equals string()->size()),
    this function will allocate a new string to return.

    \sa string()
*/

QString QStringRef::toString() const {
    if (!m_string)
        return QString();
    if (m_size && m_position == 0 && m_size == m_string->size())
        return *m_string;
    return QString(m_string->unicode() + m_position, m_size);
}


/*! \relates QStringRef

   Returns true if string reference \a s1 is lexically equal to string reference \a s2; otherwise
   returns false.
*/
bool operator==(const QStringRef &s1,const QStringRef &s2)
{ return (s1.size() == s2.size() &&
          qMemEquals((const ushort *)s1.unicode(), (const ushort *)s2.unicode(), s1.size()));
}

/*! \relates QStringRef

   Returns true if string \a s1 is lexically equal to string reference \a s2; otherwise
   returns false.
*/
bool operator==(const QString &s1,const QStringRef &s2)
{ return (s1.size() == s2.size() &&
          qMemEquals((const ushort *)s1.unicode(), (const ushort *)s2.unicode(), s1.size()));
}

/*! \relates QStringRef

   Returns true if string  \a s1 is lexically equal to string reference \a s2; otherwise
   returns false.
*/
bool operator==(const QLatin1String &s1, const QStringRef &s2)
{
    const ushort *uc = reinterpret_cast<const ushort *>(s2.unicode());
    const ushort *e = uc + s2.size();
    const uchar *c = reinterpret_cast<const uchar *>(s1.latin1());
    if (!c)
        return s2.isEmpty();

    while (*c) {
        if (uc == e || *uc != *c)
            return false;
        ++uc;
        ++c;
    }
    return (uc == e);
}

/*!
   \relates QStringRef

    Returns true if string reference \a s1 is lexically less than
    string reference \a s2; otherwise returns false.

    The comparison is based exclusively on the numeric Unicode values
    of the characters and is very fast, but is not what a human would
    expect. Consider sorting user-interface strings using the
    QString::localeAwareCompare() function.
*/
bool operator<(const QStringRef &s1,const QStringRef &s2)
{
    return ucstrcmp(s1.constData(), s1.length(), s2.constData(), s2.length()) < 0;
}

/*!\fn bool operator<=(const QStringRef &s1,const QStringRef &s2)

   \relates QStringRef

    Returns true if string reference \a s1 is lexically less than
    or equal to string reference \a s2; otherwise returns false.

    The comparison is based exclusively on the numeric Unicode values
    of the characters and is very fast, but is not what a human would
    expect. Consider sorting user-interface strings using the
    QString::localeAwareCompare() function.
*/

/*!\fn bool operator>=(const QStringRef &s1,const QStringRef &s2)

   \relates QStringRef

    Returns true if string reference \a s1 is lexically greater than
    or equal to string reference \a s2; otherwise returns false.

    The comparison is based exclusively on the numeric Unicode values
    of the characters and is very fast, but is not what a human would
    expect. Consider sorting user-interface strings using the
    QString::localeAwareCompare() function.
*/

/*!\fn bool operator>(const QStringRef &s1,const QStringRef &s2)

   \relates QStringRef

    Returns true if string reference \a s1 is lexically greater than
    string reference \a s2; otherwise returns false.

    The comparison is based exclusively on the numeric Unicode values
    of the characters and is very fast, but is not what a human would
    expect. Consider sorting user-interface strings using the
    QString::localeAwareCompare() function.
*/


/*!
    \fn const QChar QStringRef::at(int position) const

    Returns the character at the given index \a position in the
    string reference.

    The \a position must be a valid index position in the string
    (i.e., 0 <= \a position < size()).
*/

/*!
    \fn void QStringRef::clear()

    Clears the contents of the string reference by making it null and empty.

    \sa isEmpty(), isNull()
*/

/*!
    \fn QStringRef &QStringRef::operator=(const QStringRef &other)

    Assigns the \a other string reference to this string reference, and
    returns the result.
*/

/*!
    \fn QStringRef &QStringRef::operator=(const QString *string)

    Constructs a string reference to the given \a string and assigns it to
    this string reference, returning the result.
*/

/*!
    \typedef QString::DataPtr
    \internal
*/

/*!
    \fn DataPtr & QString::data_ptr()
    \internal
*/



/*!  Appends the string reference to \a string, and returns a new
reference to the combined string data.
 */
QStringRef QStringRef::appendTo(QString *string) const
{
    if (!string)
        return QStringRef();
    int pos = string->size();
    string->insert(pos, unicode(), size());
    return QStringRef(string, pos, size());
}

/*!
    \fn int QStringRef::compare(const QStringRef &s1, const QString &s2, Qt::CaseSensitivity cs = Qt::CaseSensitive)
    \since 4.5

    Compares the string \a s1 with the string \a s2 and returns an
    integer less than, equal to, or greater than zero if \a s1
    is less than, equal to, or greater than \a s2.

    If \a cs is Qt::CaseSensitive, the comparison is case sensitive;
    otherwise the comparison is case insensitive.
*/

/*!
    \fn int QStringRef::compare(const QStringRef &s1, const QStringRef &s2, Qt::CaseSensitivity cs = Qt::CaseSensitive)
    \since 4.5
    \overload

    Compares the string \a s1 with the string \a s2 and returns an
    integer less than, equal to, or greater than zero if \a s1
    is less than, equal to, or greater than \a s2.

    If \a cs is Qt::CaseSensitive, the comparison is case sensitive;
    otherwise the comparison is case insensitive.
*/

/*!
    \fn int QStringRef::compare(const QStringRef &s1, QLatin1String s2, Qt::CaseSensitivity cs = Qt::CaseSensitive)
    \since 4.5
    \overload

    Compares the string \a s1 with the string \a s2 and returns an
    integer less than, equal to, or greater than zero if \a s1
    is less than, equal to, or greater than \a s2.

    If \a cs is Qt::CaseSensitive, the comparison is case sensitive;
    otherwise the comparison is case insensitive.
*/

/*!
    \overload
    \fn int QStringRef::compare(const QString &other, Qt::CaseSensitivity cs = Qt::CaseSensitive) const
    \since 4.5

    Compares this string with the \a other string and returns an
    integer less than, equal to, or greater than zero if this string
    is less than, equal to, or greater than the \a other string.

    If \a cs is Qt::CaseSensitive, the comparison is case sensitive;
    otherwise the comparison is case insensitive.

    Equivalent to \c {compare(*this, other, cs)}.

    \sa QString::compare()
*/

/*!
    \overload
    \fn int QStringRef::compare(const QStringRef &other, Qt::CaseSensitivity cs = Qt::CaseSensitive) const
    \since 4.5

    Compares this string with the \a other string and returns an
    integer less than, equal to, or greater than zero if this string
    is less than, equal to, or greater than the \a other string.

    If \a cs is Qt::CaseSensitive, the comparison is case sensitive;
    otherwise the comparison is case insensitive.

    Equivalent to \c {compare(*this, other, cs)}.

    \sa QString::compare()
*/

/*!
    \overload
    \fn int QStringRef::compare(QLatin1String other, Qt::CaseSensitivity cs = Qt::CaseSensitive) const
    \since 4.5

    Compares this string with the \a other string and returns an
    integer less than, equal to, or greater than zero if this string
    is less than, equal to, or greater than the \a other string.

    If \a cs is Qt::CaseSensitive, the comparison is case sensitive;
    otherwise the comparison is case insensitive.

    Equivalent to \c {compare(*this, other, cs)}.

    \sa QString::compare()
*/

/*!
    \fn int QStringRef::localeAwareCompare(const QStringRef &s1, const QString & s2)
    \since 4.5

    Compares \a s1 with \a s2 and returns an integer less than, equal
    to, or greater than zero if \a s1 is less than, equal to, or
    greater than \a s2.

    The comparison is performed in a locale- and also
    platform-dependent manner. Use this function to present sorted
    lists of strings to the user.

    On Mac OS X, this function compares according the
    "Order for sorted lists" setting in the International prefereces panel.

    \sa compare(), QTextCodec::locale()
*/

/*!
    \fn int QStringRef::localeAwareCompare(const QStringRef &s1, const QStringRef & s2)
    \since 4.5
    \overload

    Compares \a s1 with \a s2 and returns an integer less than, equal
    to, or greater than zero if \a s1 is less than, equal to, or
    greater than \a s2.

    The comparison is performed in a locale- and also
    platform-dependent manner. Use this function to present sorted
    lists of strings to the user.

*/

/*!
    \fn int QStringRef::localeAwareCompare(const QString &other) const
    \since 4.5
    \overload

    Compares this string with the \a other string and returns an
    integer less than, equal to, or greater than zero if this string
    is less than, equal to, or greater than the \a other string.

    The comparison is performed in a locale- and also
    platform-dependent manner. Use this function to present sorted
    lists of strings to the user.
*/

/*!
    \fn int QStringRef::localeAwareCompare(const QStringRef &other) const
    \since 4.5
    \overload

    Compares this string with the \a other string and returns an
    integer less than, equal to, or greater than zero if this string
    is less than, equal to, or greater than the \a other string.

    The comparison is performed in a locale- and also
    platform-dependent manner. Use this function to present sorted
    lists of strings to the user.
*/

/*!
    \fn QString &QString::append(const QStringRef &reference)
    \since 4.4

    Appends the given string \a reference to this string and returns the result.
 */
QString &QString::append(const QStringRef &str)
{
    if (str.string() == this) {
        str.appendTo(this);
    } else if (str.string()) {
        int oldSize = size();
        resize(oldSize + str.size());
        memcpy(data() + oldSize, str.unicode(), str.size() * sizeof(QChar));
    }
    return *this;
}

/*!
    \since 4.4

    Returns a substring reference to the \a n leftmost characters
    of the string.

    If \a n is greater than size() or less than zero, a reference to the entire
    string is returned.

    \snippet doc/src/snippets/qstring/main.cpp leftRef

    \sa left(), rightRef(), midRef(), startsWith()
*/
QStringRef QString::leftRef(int n)  const
{
    if (n >= d->size || n < 0)
        n = d->size;
    return QStringRef(this, 0, n);
}

/*!
    \since 4.4

    Returns a substring reference to the \a n rightmost characters
    of the string.

    If \a n is greater than size() or less than zero, a reference to the entire
    string is returned.

    \snippet doc/src/snippets/qstring/main.cpp rightRef

    \sa right(), leftRef(), midRef(), endsWith()
*/
QStringRef QString::rightRef(int n) const
{
    if (n >= d->size || n < 0)
        n = d->size;
    return QStringRef(this, d->size - n, n);
}

/*!
    \since 4.4

    Returns a substring reference to \a n characters of this string,
    starting at the specified \a position.

    If the \a position exceeds the length of the string, an empty
    reference is returned.

    If there are less than \a n characters available in the string,
    starting at the given \a position, or if \a n is -1 (default), the
    function returns all characters from the specified \a position
    onwards.

    Example:

    \snippet doc/src/snippets/qstring/main.cpp midRef

    \sa mid(), leftRef(), rightRef()
*/

QStringRef QString::midRef(int position, int n) const
{
    if (d == &shared_null || position >= d->size)
        return QStringRef();
    if (n < 0)
        n = d->size - position;
    if (position < 0) {
        n += position;
        position = 0;
    }
    if (n + position > d->size)
        n = d->size - position;
    return QStringRef(this, position, n);
}

/*!
  \since 4.8

  Returns the index position of the first occurrence of the string \a
  str in this string reference, searching forward from index position
  \a from. Returns -1 if \a str is not found.

  If \a cs is Qt::CaseSensitive (default), the search is case
  sensitive; otherwise the search is case insensitive.

  If \a from is -1, the search starts at the last character; if it is
  -2, at the next to last character and so on.

  \sa QString::indexOf(), lastIndexOf(), contains(), count()
*/
int QStringRef::indexOf(const QString &str, int from, Qt::CaseSensitivity cs) const
{
    return qFindString(unicode(), length(), from, str.unicode(), str.length(), cs);
}

/*!
    \since 4.8
    \overload indexOf()

    Returns the index position of the first occurrence of the
    character \a ch in the string reference, searching forward from
    index position \a from. Returns -1 if \a ch could not be found.

    \sa QString::indexOf(), lastIndexOf(), contains(), count()
*/
int QStringRef::indexOf(QChar ch, int from, Qt::CaseSensitivity cs) const
{
    return findChar(unicode(), length(), ch, from, cs);
}

/*!
  \since 4.8

  Returns the index position of the first occurrence of the string \a
  str in this string reference, searching forward from index position
  \a from. Returns -1 if \a str is not found.

  If \a cs is Qt::CaseSensitive (default), the search is case
  sensitive; otherwise the search is case insensitive.

  If \a from is -1, the search starts at the last character; if it is
  -2, at the next to last character and so on.

  \sa QString::indexOf(), lastIndexOf(), contains(), count()
*/
int QStringRef::indexOf(QLatin1String str, int from, Qt::CaseSensitivity cs) const
{
    return qt_find_latin1_string(unicode(), size(), str, from, cs);
}

/*!
    \since 4.8

    \overload indexOf()

    Returns the index position of the first occurrence of the string
    reference \a str in this string reference, searching forward from
    index position \a from. Returns -1 if \a str is not found.

    If \a cs is Qt::CaseSensitive (default), the search is case
    sensitive; otherwise the search is case insensitive.

    \sa QString::indexOf(), lastIndexOf(), contains(), count()
*/
int QStringRef::indexOf(const QStringRef &str, int from, Qt::CaseSensitivity cs) const
{
    return qFindString(unicode(), size(), from, str.unicode(), str.size(), cs);
}

/*!
  \since 4.8

  Returns the index position of the last occurrence of the string \a
  str in this string reference, searching backward from index position
  \a from. If \a from is -1 (default), the search starts at the last
  character; if \a from is -2, at the next to last character and so
  on. Returns -1 if \a str is not found.

  If \a cs is Qt::CaseSensitive (default), the search is case
  sensitive; otherwise the search is case insensitive.

  \sa QString::lastIndexOf(), indexOf(), contains(), count()
*/
int QStringRef::lastIndexOf(const QString &str, int from, Qt::CaseSensitivity cs) const
{
    const int sl = str.size();
    if (sl == 1)
        return lastIndexOf(str.at(0), from, cs);

    const int l = size();;
    if (from < 0)
        from += l;
    int delta = l - sl;
    if (from == l && sl == 0)
        return from;
    if (from < 0 || from >= l || delta < 0)
        return -1;
    if (from > delta)
        from = delta;

    return lastIndexOfHelper(reinterpret_cast<const ushort*>(unicode()), from,
                             reinterpret_cast<const ushort*>(str.unicode()), str.size(), cs);
}

/*!
  \since 4.8
  \overload lastIndexOf()

  Returns the index position of the last occurrence of the character
  \a ch, searching backward from position \a from.

  \sa QString::lastIndexOf(), indexOf(), contains(), count()
*/
int QStringRef::lastIndexOf(QChar ch, int from, Qt::CaseSensitivity cs) const
{
    return qt_last_index_of(unicode(), size(), ch, from, cs);
}

/*!
  \since 4.8
  \overload lastIndexOf()

  Returns the index position of the last occurrence of the string \a
  str in this string reference, searching backward from index position
  \a from. If \a from is -1 (default), the search starts at the last
  character; if \a from is -2, at the next to last character and so
  on. Returns -1 if \a str is not found.

  If \a cs is Qt::CaseSensitive (default), the search is case
  sensitive; otherwise the search is case insensitive.

  \sa QString::lastIndexOf(), indexOf(), contains(), count()
*/
int QStringRef::lastIndexOf(QLatin1String str, int from, Qt::CaseSensitivity cs) const
{
    const int sl = qstrlen(str.latin1());
    if (sl == 1)
        return lastIndexOf(QLatin1Char(str.latin1()[0]), from, cs);

    const int l = size();
    if (from < 0)
        from += l;
    int delta = l - sl;
    if (from == l && sl == 0)
        return from;
    if (from < 0 || from >= l || delta < 0)
        return -1;
    if (from > delta)
        from = delta;

    QVarLengthArray<ushort> s(sl);
    for (int i = 0; i < sl; ++i)
        s[i] = str.latin1()[i];

    return lastIndexOfHelper(reinterpret_cast<const ushort*>(unicode()), from, s.data(), sl, cs);
}

/*!
  \since 4.8
  \overload lastIndexOf()

  Returns the index position of the last occurrence of the string
  reference \a str in this string reference, searching backward from
  index position \a from. If \a from is -1 (default), the search
  starts at the last character; if \a from is -2, at the next to last
  character and so on. Returns -1 if \a str is not found.

  If \a cs is Qt::CaseSensitive (default), the search is case
  sensitive; otherwise the search is case insensitive.

  \sa QString::lastIndexOf(), indexOf(), contains(), count()
*/
int QStringRef::lastIndexOf(const QStringRef &str, int from, Qt::CaseSensitivity cs) const
{
    const int sl = str.size();
    if (sl == 1)
        return lastIndexOf(str.at(0), from, cs);

    const int l = size();
    if (from < 0)
        from += l;
    int delta = l - sl;
    if (from == l && sl == 0)
        return from;
    if (from < 0 || from >= l || delta < 0)
        return -1;
    if (from > delta)
        from = delta;

    return lastIndexOfHelper(reinterpret_cast<const ushort*>(unicode()), from,
                             reinterpret_cast<const ushort*>(str.unicode()),
                             str.size(), cs);
}

/*!
    \since 4.8
    Returns the number of (potentially overlapping) occurrences of
    the string \a str in this string reference.

    If \a cs is Qt::CaseSensitive (default), the search is
    case sensitive; otherwise the search is case insensitive.

    \sa QString::count(), contains(), indexOf()
*/
int QStringRef::count(const QString &str, Qt::CaseSensitivity cs) const
{
    return qt_string_count(unicode(), size(), str.unicode(), str.size(), cs);
}

/*!
    \since 4.8
    \overload count()

    Returns the number of occurrences of the character \a ch in the
    string reference.

    If \a cs is Qt::CaseSensitive (default), the search is
    case sensitive; otherwise the search is case insensitive.

    \sa QString::count(), contains(), indexOf()
*/
int QStringRef::count(QChar ch, Qt::CaseSensitivity cs) const
{
    return qt_string_count(unicode(), size(), ch, cs);
}

/*!
    \since 4.8
    \overload count()

    Returns the number of (potentially overlapping) occurrences of the
    string reference \a str in this string reference.

    If \a cs is Qt::CaseSensitive (default), the search is
    case sensitive; otherwise the search is case insensitive.

    \sa QString::count(), contains(), indexOf()
*/
int QStringRef::count(const QStringRef &str, Qt::CaseSensitivity cs) const
{
    return qt_string_count(unicode(), size(), str.unicode(), str.size(), cs);
}

/*!
    \since 4.8

    Returns true if the string reference starts with \a str; otherwise
    returns false.

    If \a cs is Qt::CaseSensitive (default), the search is
    case sensitive; otherwise the search is case insensitive.

    \sa QString::startsWith(), endsWith()
*/
bool QStringRef::startsWith(const QString &str, Qt::CaseSensitivity cs) const
{
    return qt_starts_with(isNull() ? 0 : unicode(), size(),
                          str.isNull() ? 0 : str.unicode(), str.size(), cs);
}

/*!
    \since 4.8
    \overload startsWith()
    \sa QString::startsWith(), endsWith()
*/
bool QStringRef::startsWith(QLatin1String str, Qt::CaseSensitivity cs) const
{
    return qt_starts_with(isNull() ? 0 : unicode(), size(), str, cs);
}

/*!
    \since 4.8
    \overload startsWith()
    \sa QString::startsWith(), endsWith()
*/
bool QStringRef::startsWith(const QStringRef &str, Qt::CaseSensitivity cs) const
{
    return qt_starts_with(isNull() ? 0 : unicode(), size(),
                          str.isNull() ? 0 : str.unicode(), str.size(), cs);
}

/*!
    \since 4.8
    \overload startsWith()

    Returns true if the string reference starts with \a ch; otherwise
    returns false.

    If \a cs is Qt::CaseSensitive (default), the search is case
    sensitive; otherwise the search is case insensitive.

    \sa QString::startsWith(), endsWith()
*/
bool QStringRef::startsWith(QChar ch, Qt::CaseSensitivity cs) const
{
    if (!isEmpty()) {
        const ushort *data = reinterpret_cast<const ushort*>(unicode());
        return (cs == Qt::CaseSensitive
                ? data[0] == ch
                : foldCase(data[0]) == foldCase(ch.unicode()));
    } else {
        return false;
    }
}

/*!
    \since 4.8
    Returns true if the string reference ends with \a str; otherwise
    returns false.

    If \a cs is Qt::CaseSensitive (default), the search is case
    sensitive; otherwise the search is case insensitive.

    \sa QString::endsWith(), startsWith()
*/
bool QStringRef::endsWith(const QString &str, Qt::CaseSensitivity cs) const
{
    return qt_ends_with(isNull() ? 0 : unicode(), size(),
                        str.isNull() ? 0 : str.unicode(), str.size(), cs);
}

/*!
    \since 4.8
    \overload endsWith()

    Returns true if the string reference ends with \a ch; otherwise
    returns false.

    If \a cs is Qt::CaseSensitive (default), the search is case
    sensitive; otherwise the search is case insensitive.

    \sa QString::endsWith(), endsWith()
*/
bool QStringRef::endsWith(QChar ch, Qt::CaseSensitivity cs) const
{
    if (!isEmpty()) {
        const ushort *data = reinterpret_cast<const ushort*>(unicode());
        const int size = length();
        return (cs == Qt::CaseSensitive
                ? data[size - 1] == ch
                : foldCase(data[size - 1]) == foldCase(ch.unicode()));
    } else {
        return false;
    }
}

/*!
    \since 4.8
    \overload endsWith()
    \sa QString::endsWith(), endsWith()
*/
bool QStringRef::endsWith(QLatin1String str, Qt::CaseSensitivity cs) const
{
    return qt_ends_with(isNull() ? 0 : unicode(), size(), str, cs);
}

/*!
    \since 4.8
    \overload endsWith()
    \sa QString::endsWith(), endsWith()
*/
bool QStringRef::endsWith(const QStringRef &str, Qt::CaseSensitivity cs) const
{
    return qt_ends_with(isNull() ? 0 : unicode(), size(),
                        str.isNull() ? 0 : str.unicode(), str.size(), cs);
}


/*! \fn bool QStringRef::contains(const QString &str, Qt::CaseSensitivity cs = Qt::CaseSensitive) const

    \since 4.8
    Returns true if this string reference contains an occurrence of
    the string \a str; otherwise returns false.

    If \a cs is Qt::CaseSensitive (default), the search is
    case sensitive; otherwise the search is case insensitive.

    \sa indexOf(), count()
*/

/*! \fn bool QStringRef::contains(QChar ch, Qt::CaseSensitivity cs = Qt::CaseSensitive) const

    \overload contains()
    \since 4.8

    Returns true if this string contains an occurrence of the
    character \a ch; otherwise returns false.

    If \a cs is Qt::CaseSensitive (default), the search is
    case sensitive; otherwise the search is case insensitive.

*/

/*! \fn bool QStringRef::contains(const QStringRef &str, Qt::CaseSensitivity cs = Qt::CaseSensitive) const
    \overload contains()
    \since 4.8

    Returns true if this string reference contains an occurrence of
    the string reference \a str; otherwise returns false.

    If \a cs is Qt::CaseSensitive (default), the search is
    case sensitive; otherwise the search is case insensitive.

    \sa indexOf(), count()
*/

/*! \fn bool QStringRef::contains(QLatin1String str, Qt::CaseSensitivity cs) const
    \since 4,8
    \overload contains()

    Returns true if this string reference contains an occurrence of
    the string \a str; otherwise returns false.

    If \a cs is Qt::CaseSensitive (default), the search is
    case sensitive; otherwise the search is case insensitive.

    \sa indexOf(), count()
*/

static inline int qt_last_index_of(const QChar *haystack, int haystackLen, const QChar &needle,
                                   int from, Qt::CaseSensitivity cs)
{
    ushort c = needle.unicode();
    if (from < 0)
        from += haystackLen;
    if (from < 0 || from >= haystackLen)
        return -1;
    if (from >= 0) {
        const ushort *b = reinterpret_cast<const ushort*>(haystack);
        const ushort *n = b + from;
        if (cs == Qt::CaseSensitive) {
            for (; n >= b; --n)
                if (*n == c)
                    return n - b;
        } else {
            c = foldCase(c);
            for (; n >= b; --n)
                if (foldCase(*n) == c)
                    return n - b;
        }
    }
    return -1;


}

static inline int qt_string_count(const QChar *haystack, int haystackLen,
                                  const QChar *needle, int needleLen,
                                  Qt::CaseSensitivity cs)
{
    int num = 0;
    int i = -1;
    if (haystackLen > 500 && needleLen > 5) {
        QStringMatcher matcher(needle, needleLen, cs);
        while ((i = matcher.indexIn(haystack, haystackLen, i + 1)) != -1)
            ++num;
    } else {
        while ((i = qFindString(haystack, haystackLen, i + 1, needle, needleLen, cs)) != -1)
            ++num;
    }
    return num;
}

static inline int qt_string_count(const QChar *unicode, int size, const QChar &ch,
                                  Qt::CaseSensitivity cs)
{
    ushort c = ch.unicode();
    int num = 0;
    const ushort *b = reinterpret_cast<const ushort*>(unicode);
    const ushort *i = b + size;
    if (cs == Qt::CaseSensitive) {
        while (i != b)
            if (*--i == c)
                ++num;
    } else {
        c = foldCase(c);
        while (i != b)
            if (foldCase(*(--i)) == c)
                ++num;
    }
    return num;
}

static inline int qt_find_latin1_string(const QChar *haystack, int size,
                                        const QLatin1String &needle,
                                        int from, Qt::CaseSensitivity cs)
{
    const char *latin1 = needle.latin1();
    int len = qstrlen(latin1);
    QVarLengthArray<ushort> s(len);
    for (int i = 0; i < len; ++i)
        s[i] = latin1[i];

    return qFindString(haystack, size, from,
                       reinterpret_cast<const QChar*>(s.constData()), len, cs);
}

static inline bool qt_starts_with(const QChar *haystack, int haystackLen,
                                  const QChar *needle, int needleLen, Qt::CaseSensitivity cs)
{
    if (!haystack)
        return !needle;
    if (haystackLen == 0)
        return needleLen == 0;
    if (needleLen > haystackLen)
        return false;

    const ushort *h = reinterpret_cast<const ushort*>(haystack);
    const ushort *n = reinterpret_cast<const ushort*>(needle);

    if (cs == Qt::CaseSensitive) {
        return qMemEquals(h, n, needleLen);
    } else {
        uint last = 0;
        uint olast = 0;
        for (int i = 0; i < needleLen; ++i)
            if (foldCase(h[i], last) != foldCase(n[i], olast))
                return false;
    }
    return true;
}

static inline bool qt_starts_with(const QChar *haystack, int haystackLen,
                                  const QLatin1String &needle, Qt::CaseSensitivity cs)
{
    if (!haystack)
        return !needle.latin1();
    if (haystackLen == 0)
        return !needle.latin1() || *needle.latin1() == 0;
    const int slen = qstrlen(needle.latin1());
    if (slen > haystackLen)
        return false;
    const ushort *data = reinterpret_cast<const ushort*>(haystack);
    const uchar *latin = reinterpret_cast<const uchar*>(needle.latin1());
    if (cs == Qt::CaseSensitive) {
        for (int i = 0; i < slen; ++i)
            if (data[i] != latin[i])
                return false;
    } else {
        for (int i = 0; i < slen; ++i)
            if (foldCase(data[i]) != foldCase((ushort)latin[i]))
                return false;
    }
    return true;
}

static inline bool qt_ends_with(const QChar *haystack, int haystackLen,
                                const QChar *needle, int needleLen, Qt::CaseSensitivity cs)
{
    if (!haystack)
        return !needle;
    if (haystackLen == 0)
        return needleLen == 0;
    const int pos = haystackLen - needleLen;
    if (pos < 0)
        return false;

    const ushort *h = reinterpret_cast<const ushort*>(haystack);
    const ushort *n = reinterpret_cast<const ushort*>(needle);

    if (cs == Qt::CaseSensitive) {
        return qMemEquals(h + pos, n, needleLen);
    } else {
        uint last = 0;
        uint olast = 0;
        for (int i = 0; i < needleLen; i++)
            if (foldCase(h[pos+i], last) != foldCase(n[i], olast))
                return false;
    }
    return true;
}


static inline bool qt_ends_with(const QChar *haystack, int haystackLen,
                                const QLatin1String &needle, Qt::CaseSensitivity cs)
{
    if (!haystack)
        return !needle.latin1();
    if (haystackLen == 0)
        return !needle.latin1() || *needle.latin1() == 0;
    const int slen = qstrlen(needle.latin1());
    int pos = haystackLen - slen;
    if (pos < 0)
        return false;
    const uchar *latin = reinterpret_cast<const uchar*>(needle.latin1());
    const ushort *data = reinterpret_cast<const ushort*>(haystack);
    if (cs == Qt::CaseSensitive) {
        for (int i = 0; i < slen; i++)
            if (data[pos+i] != latin[i])
                return false;
    } else {
        for (int i = 0; i < slen; i++)
            if (foldCase(data[pos+i]) != foldCase((ushort)latin[i]))
                return false;
    }
    return true;
}

/*!
    \since 4.8

    Returns a Latin-1 representation of the string as a QByteArray.

    The returned byte array is undefined if the string contains non-Latin1
    characters. Those characters may be suppressed or replaced with a
    question mark.

    \sa toAscii(), toUtf8(), toLocal8Bit(), QTextCodec
*/
QByteArray QStringRef::toLatin1() const
{
    return toLatin1_helper(unicode(), length());
}

/*!
    \since 4.8

    Returns an 8-bit representation of the string as a QByteArray.

    If a codec has been set using QTextCodec::setCodecForCStrings(),
    it is used to convert Unicode to 8-bit char; otherwise this
    function does the same as toLatin1().

    Note that, despite the name, this function does not necessarily return an US-ASCII
    (ANSI X3.4-1986) string and its result may not be US-ASCII compatible.

    \sa toLatin1(), toUtf8(), toLocal8Bit(), QTextCodec
*/
QByteArray QStringRef::toAscii() const
{
#ifndef QT_NO_TEXTCODEC
    if (QString::codecForCStrings)
        return QString::codecForCStrings->fromUnicode(unicode(), length());
#endif // QT_NO_TEXTCODEC
    return toLatin1();
}

/*!
    \since 4.8

    Returns the local 8-bit representation of the string as a
    QByteArray. The returned byte array is undefined if the string
    contains characters not supported by the local 8-bit encoding.

    QTextCodec::codecForLocale() is used to perform the conversion from
    Unicode. If the locale encoding could not be determined, this function
    does the same as toLatin1().

    If this string contains any characters that cannot be encoded in the
    locale, the returned byte array is undefined. Those characters may be
    suppressed or replaced by another.

    \sa toAscii(), toLatin1(), toUtf8(), QTextCodec
*/
QByteArray QStringRef::toLocal8Bit() const
{
#ifndef QT_NO_TEXTCODEC
    if (QTextCodec::codecForLocale())
        return QTextCodec::codecForLocale()->fromUnicode(unicode(), length());
#endif // QT_NO_TEXTCODEC
    return toLatin1();
}

/*!
    \since 4.8

    Returns a UTF-8 representation of the string as a QByteArray.

    UTF-8 is a Unicode codec and can represent all characters in a Unicode
    string like QString.

    However, in the Unicode range, there are certain codepoints that are not
    considered characters. The Unicode standard reserves the last two
    codepoints in each Unicode Plane (U+FFFE, U+FFFF, U+1FFFE, U+1FFFF,
    U+2FFFE, etc.), as well as 16 codepoints in the range U+FDD0..U+FDDF,
    inclusive, as non-characters. If any of those appear in the string, they
    may be discarded and will not appear in the UTF-8 representation, or they
    may be replaced by one or more replacement characters.

    \sa toAscii(), toLatin1(), toLocal8Bit(), QTextCodec
*/
QByteArray QStringRef::toUtf8() const
{
    if (isNull())
        return QByteArray();

    return QUtf8::convertFromUnicode(constData(), length(), 0);
}

/*!
    \since 4.8

    Returns a UCS-4/UTF-32 representation of the string as a QVector<uint>.

    UCS-4 is a Unicode codec and is lossless. All characters from this string
    can be encoded in UCS-4.

    \sa toAscii(), toLatin1(), toLocal8Bit(), QTextCodec
*/
QVector<uint> QStringRef::toUcs4() const
{
    QVector<uint> v(length());
    uint *a = v.data();
    int len = toUcs4_helper<uint>(reinterpret_cast<const unsigned short *>(unicode()), length(), a);
    v.resize(len);
    return v;
}

QT_END_NAMESPACE