doc: Added explanation of QStringBuilder in QString

The QStringBuilder class documentation is marked \internal.
A section has been added to the documentation for QString
that explains how to use the reimplemented '%' operator of
QStringBuilder to obtain more efficient string concatenation
operations.

1 files changed, 28 insertions, 0 deletions

diff --git a/doc/src/snippets/qstring/stringbuilder.cpp b/doc/src/snippets/qstring/stringbuilder.cpp
new file mode 100644
index 0000000..90803e2
--- /dev/null
+++ b/doc/src/snippets/qstring/stringbuilder.cpp
@@ -0,0 +1,28 @@
+
+//! [0]
+    QString foo;
+    QString type = "long";
+
+    foo->setText(QLatin1String("vector<") + type + QLatin1String(">::iterator"));
+
+    if (foo.startsWith("(" + type + ") 0x"))
+        ...
+//! [0]
+
+//! [3]
+    #define QT_USE_FAST_CONCATENATION        
+//! [3]
+
+//! [4]
+    #define QT_USE_FAST_CONCATENATION 
+    #define QT_USE_FAST_OPERATOR_PLUS 
+//! [4]
+
+//! [5]
+    #include <QStringBuilder>
+
+    QString hello("hello");
+    QStringRef el(&hello, 2, 3);
+    QLatin1String world("world");
+    QString message =  hello % el % world % QChar('!');
+//! [5]