String: Add a custom string type

Create a `cm::String` type that holds a view of a string buffer and
optionally shares ownership of the buffer.  Instances can either
borrow longer-lived storage (e.g. static storage of string literals)
or internally own a `std::string` instance.  In the latter case,
share ownership with copies and substrings.  Allocate a new internal
string only on operations that require mutation.

This will allow us to recover string sharing semantics that we
used to get from C++98 std::string copy-on-write implementations.
Such implementations are not allowed by C++11 so code our own in
a custom string type instead.

2 files changed, 1111 insertions, 0 deletions

diff --git a/Tests/CMakeLib/CMakeLists.txt b/Tests/CMakeLib/CMakeLists.txt
index 126076d..f6a9153 100644
--- a/Tests/CMakeLib/CMakeLists.txt
+++ b/Tests/CMakeLib/CMakeLists.txt
@@ -7,6 +7,7 @@ include_directories(
 set(CMakeLib_TESTS
   testGeneratedFileStream.cxx
   testRST.cxx
+  testString.cxx
   testSystemTools.cxx
   testUTF8.cxx
   testXMLParser.cxx
diff --git a/Tests/CMakeLib/testString.cxx b/Tests/CMakeLib/testString.cxx
new file mode 100644
index 0000000..9fe2e39
--- /dev/null
+++ b/Tests/CMakeLib/testString.cxx
@@ -0,0 +1,1110 @@
+/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+   file Copyright.txt or https://cmake.org/licensing for details.  */
+
+#include "cmString.hxx"
+
+#include "cm_string_view.hxx"
+
+#include <cstring>
+#include <iostream>
+#include <iterator>
+#include <sstream>
+#include <stdexcept>
+#include <string>
+#include <utility>
+
+#define ASSERT_TRUE(x)                                                        \
+  if (!(x)) {                                                                 \
+    std::cout << "ASSERT_TRUE(" #x ") failed on line " << __LINE__ << "\n";   \
+    return false;                                                             \
+  }
+
+static bool testConstructDefault()
+{
+  std::cout << "testConstructDefault()\n";
+  cm::String str;
+  cm::String const& str_const = str;
+  ASSERT_TRUE(bool(str_const) == false);
+  ASSERT_TRUE(str_const.data() == nullptr);
+  ASSERT_TRUE(str_const.size() == 0);
+  ASSERT_TRUE(str_const.empty());
+  ASSERT_TRUE(str.c_str() == nullptr);
+  ASSERT_TRUE(str.str().empty());
+  return true;
+}
+
+static bool testFromNullPtr(cm::String str)
+{
+  cm::String const& str_const = str;
+  ASSERT_TRUE(bool(str_const) == false);
+  ASSERT_TRUE(str_const.data() == nullptr);
+  ASSERT_TRUE(str_const.size() == 0);
+  ASSERT_TRUE(str_const.empty());
+  ASSERT_TRUE(str.c_str() == nullptr);
+  ASSERT_TRUE(str.str().empty());
+  return true;
+}
+
+static bool testConstructFromNullPtr()
+{
+  std::cout << "testConstructFromNullPtr()\n";
+  return testFromNullPtr(nullptr);
+}
+
+static bool testAssignFromNullPtr()
+{
+  std::cout << "testAssignFromNullPtr()\n";
+  cm::String str;
+  str = nullptr;
+  return testFromNullPtr(str);
+}
+
+static bool testFromCStrNull(cm::String str)
+{
+  cm::String const& str_const = str;
+  ASSERT_TRUE(bool(str_const) == false);
+  ASSERT_TRUE(str_const.data() == nullptr);
+  ASSERT_TRUE(str_const.size() == 0);
+  ASSERT_TRUE(str_const.empty());
+  ASSERT_TRUE(str.c_str() == nullptr);
+  ASSERT_TRUE(str.str().empty());
+  return true;
+}
+
+static bool testConstructFromCStrNull()
+{
+  std::cout << "testConstructFromCStrNull()\n";
+  const char* null = nullptr;
+  return testFromCStrNull(null);
+}
+
+static bool testAssignFromCStrNull()
+{
+  std::cout << "testAssignFromCStrNull()\n";
+  const char* null = nullptr;
+  cm::String str;
+  str = null;
+  return testFromCStrNull(str);
+}
+
+static char const charArray[] = "abc";
+
+static bool testFromCharArray(cm::String str)
+{
+  cm::String const& str_const = str;
+  ASSERT_TRUE(str_const.data() != charArray);
+  ASSERT_TRUE(str_const.size() == sizeof(charArray) - 1);
+  ASSERT_TRUE(str.c_str() != charArray);
+  cm::String substr = str.substr(1);
+  cm::String const& substr_const = substr;
+  ASSERT_TRUE(substr_const.data() != &charArray[1]);
+  ASSERT_TRUE(substr_const.size() == 2);
+  ASSERT_TRUE(substr.c_str() != &charArray[1]);
+  return true;
+}
+
+static bool testConstructFromCharArray()
+{
+  std::cout << "testConstructFromCharArray()\n";
+  return testFromCharArray(charArray);
+}
+
+static bool testAssignFromCharArray()
+{
+  std::cout << "testAssignFromCharArray()\n";
+  cm::String str;
+  str = charArray;
+  return testFromCharArray(str);
+}
+
+static const char* cstr = "abc";
+
+static bool testFromCStr(cm::String const& str)
+{
+  ASSERT_TRUE(str.data() != cstr);
+  ASSERT_TRUE(str.size() == 3);
+  ASSERT_TRUE(std::strncmp(str.data(), cstr, 3) == 0);
+  return true;
+}
+
+static bool testConstructFromCStr()
+{
+  std::cout << "testConstructFromCStr()\n";
+  return testFromCStr(cstr);
+  ;
+}
+
+static bool testAssignFromCStr()
+{
+  std::cout << "testAssignFromCStr()\n";
+  cm::String str;
+  str = cstr;
+  return testFromCStr(str);
+  ;
+}
+
+static const std::string stdstr = "abc";
+
+static bool testFromStdString(cm::String const& str)
+{
+#if defined(_GLIBCXX_USE_CXX11_ABI) && _GLIBCXX_USE_CXX11_ABI
+  // It would be nice to check this everywhere, but several platforms
+  // still use a CoW implementation even in C++11.
+  ASSERT_TRUE(str.data() != stdstr.data());
+#endif
+  ASSERT_TRUE(str.size() == 3);
+  ASSERT_TRUE(std::strncmp(str.data(), stdstr.data(), 3) == 0);
+  return true;
+}
+
+static bool testConstructFromStdString()
+{
+  std::cout << "testConstructFromStdString()\n";
+  return testFromStdString(stdstr);
+}
+
+static bool testAssignFromStdString()
+{
+  std::cout << "testAssignFromStdString()\n";
+  cm::String str;
+  str = stdstr;
+  return testFromStdString(str);
+}
+
+static bool testConstructFromView()
+{
+  std::cout << "testConstructFromView()\n";
+  cm::string_view view = cstr;
+  return testFromCStr(view);
+}
+
+static bool testAssignFromView()
+{
+  std::cout << "testAssignFromView()\n";
+  cm::string_view view = cstr;
+  cm::String str;
+  str = view;
+  return testFromCStr(str);
+}
+
+static bool testFromChar(cm::String const& str)
+{
+  ASSERT_TRUE(str.size() == 1);
+  ASSERT_TRUE(std::strncmp(str.data(), "a", 1) == 0);
+  return true;
+}
+
+static bool testConstructFromChar()
+{
+  std::cout << "testConstructFromChar()\n";
+  return testFromChar('a');
+}
+
+static bool testAssignFromChar()
+{
+  std::cout << "testAssignFromChar()\n";
+  cm::String str;
+  str = 'a';
+  return testFromChar(str);
+}
+
+static bool testConstructFromInitList()
+{
+  std::cout << "testConstructFromInitList()\n";
+  cm::String const str{ 'a', 'b', 'c' };
+  ASSERT_TRUE(str.size() == 3);
+  ASSERT_TRUE(std::strncmp(str.data(), "abc", 3) == 0);
+  return true;
+}
+
+static bool testAssignFromInitList()
+{
+  std::cout << "testAssignFromInitList()\n";
+  cm::String str;
+  str = { 'a', 'b', 'c' };
+  ASSERT_TRUE(str.size() == 3);
+  ASSERT_TRUE(std::strncmp(str.data(), "abc", 3) == 0);
+  return true;
+}
+
+static bool testConstructFromBuffer()
+{
+  std::cout << "testConstructFromBuffer()\n";
+  cm::String const str(cstr, 3);
+  return testFromCStr(str);
+}
+
+static bool testConstructFromInputIterator()
+{
+  std::cout << "testConstructFromInputIterator()\n";
+  cm::String const str(cstr, cstr + 3);
+  ASSERT_TRUE(str.data() != cstr);
+  ASSERT_TRUE(str.size() == 3);
+  ASSERT_TRUE(std::strncmp(str.data(), cstr, 3) == 0);
+  return true;
+}
+
+static bool testConstructFromN()
+{
+  std::cout << "testConstructFromN()\n";
+  cm::String const str(3, 'a');
+  ASSERT_TRUE(str.size() == 3);
+  ASSERT_TRUE(std::strncmp(str.data(), "aaa", 3) == 0);
+  return true;
+}
+
+static bool testConstructCopy()
+{
+  std::cout << "testConstructCopy()\n";
+  cm::String s1 = std::string("abc");
+  cm::String s2 = s1;
+  ASSERT_TRUE(s1.data() == s2.data());
+  ASSERT_TRUE(s1.size() == 3);
+  ASSERT_TRUE(s2.size() == 3);
+  ASSERT_TRUE(std::strncmp(s2.data(), "abc", 3) == 0);
+  return true;
+}
+
+static bool testConstructMove()
+{
+  std::cout << "testConstructMove()\n";
+  cm::String s1 = std::string("abc");
+  cm::String s2 = std::move(s1);
+  ASSERT_TRUE(s1.data() == nullptr);
+  ASSERT_TRUE(s1.size() == 0);
+  ASSERT_TRUE(s2.size() == 3);
+  ASSERT_TRUE(std::strncmp(s2.data(), "abc", 3) == 0);
+  return true;
+}
+
+static bool testAssignCopy()
+{
+  std::cout << "testAssignCopy()\n";
+  cm::String s1 = std::string("abc");
+  cm::String s2;
+  s2 = s1;
+  ASSERT_TRUE(s1.data() == s2.data());
+  ASSERT_TRUE(s1.size() == 3);
+  ASSERT_TRUE(s2.size() == 3);
+  ASSERT_TRUE(std::strncmp(s2.data(), "abc", 3) == 0);
+  return true;
+}
+
+static bool testAssignMove()
+{
+  std::cout << "testAssignMove()\n";
+  cm::String s1 = std::string("abc");
+  cm::String s2;
+  s2 = std::move(s1);
+  ASSERT_TRUE(s1.data() == nullptr);
+  ASSERT_TRUE(s1.size() == 0);
+  ASSERT_TRUE(s2.size() == 3);
+  ASSERT_TRUE(std::strncmp(s2.data(), "abc", 3) == 0);
+  return true;
+}
+
+static bool testOperatorBool()
+{
+  std::cout << "testOperatorBool()\n";
+  cm::String str;
+  ASSERT_TRUE(!str);
+  str = "";
+  ASSERT_TRUE(str);
+  str = static_cast<const char*>(nullptr);
+  ASSERT_TRUE(!str);
+  str = std::string();
+  ASSERT_TRUE(str);
+  str = nullptr;
+  ASSERT_TRUE(!str);
+  return true;
+}
+
+static bool testOperatorIndex()
+{
+  std::cout << "testOperatorIndex()\n";
+  cm::String str = "abc";
+  ASSERT_TRUE(str[0] == 'a');
+  ASSERT_TRUE(str[1] == 'b');
+  ASSERT_TRUE(str[2] == 'c');
+  return true;
+}
+
+static bool testOperatorPlusEqual()
+{
+  std::cout << "testOperatorPlusEqual()\n";
+  cm::String str = "a";
+  str += "b";
+  {
+    const char* c = "c";
+    str += c;
+  }
+  str += 'd';
+  str += std::string("e");
+  str += cm::string_view("f", 1);
+  str += cm::String("g");
+  ASSERT_TRUE(str.size() == 7);
+  ASSERT_TRUE(std::strncmp(str.data(), "abcdefg", 7) == 0);
+  return true;
+}
+
+static bool testOperatorCompare()
+{
+  std::cout << "testOperatorCompare()\n";
+  cm::String str = "b";
+  {
+    ASSERT_TRUE(str == "b");
+    ASSERT_TRUE("b" == str);
+    ASSERT_TRUE(str != "a");
+    ASSERT_TRUE("a" != str);
+    ASSERT_TRUE(str < "c");
+    ASSERT_TRUE("a" < str);
+    ASSERT_TRUE(str > "a");
+    ASSERT_TRUE("c" > str);
+    ASSERT_TRUE(str <= "b");
+    ASSERT_TRUE("b" <= str);
+    ASSERT_TRUE(str >= "b");
+    ASSERT_TRUE("b" >= str);
+  }
+  {
+    const char* a = "a";
+    const char* b = "b";
+    const char* c = "c";
+    ASSERT_TRUE(str == b);
+    ASSERT_TRUE(b == str);
+    ASSERT_TRUE(str != a);
+    ASSERT_TRUE(a != str);
+    ASSERT_TRUE(str < c);
+    ASSERT_TRUE(a < str);
+    ASSERT_TRUE(str > a);
+    ASSERT_TRUE(c > str);
+    ASSERT_TRUE(str <= b);
+    ASSERT_TRUE(b <= str);
+    ASSERT_TRUE(str >= b);
+    ASSERT_TRUE(b >= str);
+  }
+  {
+    ASSERT_TRUE(str == 'b');
+    ASSERT_TRUE('b' == str);
+    ASSERT_TRUE(str != 'a');
+    ASSERT_TRUE('a' != str);
+    ASSERT_TRUE(str < 'c');
+    ASSERT_TRUE('a' < str);
+    ASSERT_TRUE(str > 'a');
+    ASSERT_TRUE('c' > str);
+    ASSERT_TRUE(str <= 'b');
+    ASSERT_TRUE('b' <= str);
+    ASSERT_TRUE(str >= 'b');
+    ASSERT_TRUE('b' >= str);
+  }
+  {
+    std::string const a = "a";
+    std::string const b = "b";
+    std::string const c = "c";
+    ASSERT_TRUE(str == b);
+    ASSERT_TRUE(b == str);
+    ASSERT_TRUE(str != a);
+    ASSERT_TRUE(a != str);
+    ASSERT_TRUE(str < c);
+    ASSERT_TRUE(a < str);
+    ASSERT_TRUE(str > a);
+    ASSERT_TRUE(c > str);
+    ASSERT_TRUE(str <= b);
+    ASSERT_TRUE(b <= str);
+    ASSERT_TRUE(str >= b);
+    ASSERT_TRUE(b >= str);
+  }
+  {
+    cm::string_view const a("a", 1);
+    cm::string_view const b("b", 1);
+    cm::string_view const c("c", 1);
+    ASSERT_TRUE(str == b);
+    ASSERT_TRUE(b == str);
+    ASSERT_TRUE(str != a);
+    ASSERT_TRUE(a != str);
+    ASSERT_TRUE(str < c);
+    ASSERT_TRUE(a < str);
+    ASSERT_TRUE(str > a);
+    ASSERT_TRUE(c > str);
+    ASSERT_TRUE(str <= b);
+    ASSERT_TRUE(b <= str);
+    ASSERT_TRUE(str >= b);
+    ASSERT_TRUE(b >= str);
+  }
+  {
+    cm::String const a("a");
+    cm::String const b("b");
+    cm::String const c("c");
+    ASSERT_TRUE(str == b);
+    ASSERT_TRUE(b == str);
+    ASSERT_TRUE(str != a);
+    ASSERT_TRUE(a != str);
+    ASSERT_TRUE(str < c);
+    ASSERT_TRUE(a < str);
+    ASSERT_TRUE(str > a);
+    ASSERT_TRUE(c > str);
+    ASSERT_TRUE(str <= b);
+    ASSERT_TRUE(b <= str);
+    ASSERT_TRUE(str >= b);
+    ASSERT_TRUE(b >= str);
+  }
+  return true;
+}
+
+static bool testOperatorStream()
+{
+  std::cout << "testOperatorStream()\n";
+  std::ostringstream ss;
+  ss << "a" << cm::String("b") << 'c';
+  ASSERT_TRUE(ss.str() == "abc");
+  return true;
+}
+
+static bool testOperatorStdStringPlusEqual()
+{
+  std::cout << "testOperatorStdStringPlusEqual()\n";
+  std::string s = "a";
+  s += cm::String("b");
+  ASSERT_TRUE(s == "ab");
+  return true;
+}
+
+static bool testMethod_view()
+{
+  std::cout << "testMethod_view()\n";
+  cm::String str;
+  ASSERT_TRUE(str.view().data() == nullptr);
+  ASSERT_TRUE(str.view().size() == 0);
+  str = charArray;
+  ASSERT_TRUE(str.view().data() != charArray);
+  ASSERT_TRUE(str.view().size() == sizeof(charArray) - 1);
+  str = std::string("abc");
+  ASSERT_TRUE(str.view().size() == 3);
+  ASSERT_TRUE(strncmp(str.view().data(), "abc", 3) == 0);
+  return true;
+}
+
+static bool testMethod_empty()
+{
+  std::cout << "testMethod_empty()\n";
+  cm::String str;
+  ASSERT_TRUE(str.empty());
+  str = "";
+  ASSERT_TRUE(str.empty());
+  str = "abc";
+  ASSERT_TRUE(!str.empty());
+  str = std::string();
+  ASSERT_TRUE(str.empty());
+  str = std::string("abc");
+  ASSERT_TRUE(!str.empty());
+  return true;
+}
+
+static bool testMethod_length()
+{
+  std::cout << "testMethod_length()\n";
+  cm::String str;
+  ASSERT_TRUE(str.length() == 0);
+  str = "";
+  ASSERT_TRUE(str.length() == 0);
+  str = "abc";
+  ASSERT_TRUE(str.length() == 3);
+  str = std::string();
+  ASSERT_TRUE(str.length() == 0);
+  str = std::string("abc");
+  ASSERT_TRUE(str.length() == 3);
+  return true;
+}
+
+static bool testMethod_at()
+{
+  std::cout << "testMethod_at()\n";
+  cm::String str = "abc";
+  ASSERT_TRUE(str.at(0) == 'a');
+  ASSERT_TRUE(str.at(1) == 'b');
+  ASSERT_TRUE(str.at(2) == 'c');
+  bool except_out_of_range = false;
+  try {
+    str.at(3);
+  } catch (std::out_of_range&) {
+    except_out_of_range = true;
+  }
+  ASSERT_TRUE(except_out_of_range);
+  return true;
+}
+
+static bool testMethod_front_back()
+{
+  std::cout << "testMethod_front_back()\n";
+  cm::String str = "abc";
+  ASSERT_TRUE(str.front() == 'a');
+  ASSERT_TRUE(str.back() == 'c');
+  return true;
+}
+
+static bool testMethodIterators()
+{
+  std::cout << "testMethodIterators()\n";
+  cm::String str = "abc";
+  ASSERT_TRUE(*str.begin() == 'a');
+  ASSERT_TRUE(*(str.end() - 1) == 'c');
+  ASSERT_TRUE(str.end() - str.begin() == 3);
+  ASSERT_TRUE(*str.cbegin() == 'a');
+  ASSERT_TRUE(*(str.cend() - 1) == 'c');
+  ASSERT_TRUE(str.cend() - str.cbegin() == 3);
+  ASSERT_TRUE(*str.rbegin() == 'c');
+  ASSERT_TRUE(*(str.rend() - 1) == 'a');
+  ASSERT_TRUE(str.rend() - str.rbegin() == 3);
+  ASSERT_TRUE(*str.crbegin() == 'c');
+  ASSERT_TRUE(*(str.crend() - 1) == 'a');
+  ASSERT_TRUE(str.crend() - str.crbegin() == 3);
+  return true;
+}
+
+static bool testMethod_clear()
+{
+  std::cout << "testMethod_clear()\n";
+  cm::String str = "abc";
+  ASSERT_TRUE(!str.empty());
+  str.clear();
+  ASSERT_TRUE(str.empty());
+  return true;
+}
+
+static bool testMethod_insert()
+{
+  std::cout << "testMethod_insert()\n";
+  cm::String str = "abc";
+  str.insert(1, 2, 'd').insert(0, 1, '_');
+  ASSERT_TRUE(str.size() == 6);
+  ASSERT_TRUE(std::strncmp(str.data(), "_addbc", 6) == 0);
+  return true;
+}
+
+static bool testMethod_erase()
+{
+  std::cout << "testMethod_erase()\n";
+  cm::String str = "abcdefg";
+  str.erase(5).erase(1, 2);
+  ASSERT_TRUE(str.size() == 3);
+  ASSERT_TRUE(std::strncmp(str.data(), "ade", 3) == 0);
+  return true;
+}
+
+static bool testMethod_push_back()
+{
+  std::cout << "testMethod_push_back()\n";
+  cm::String str = "abc";
+  str.push_back('d');
+  ASSERT_TRUE(str == "abcd");
+  return true;
+}
+
+static bool testMethod_pop_back()
+{
+  std::cout << "testMethod_pop_back()\n";
+  cm::String str = "abc";
+  str.pop_back();
+  ASSERT_TRUE(str == "ab");
+  return true;
+}
+
+static bool testMethod_replace()
+{
+  std::cout << "testMethod_replace()\n";
+  {
+    cm::String str = "abcd";
+    const char* bc = "bc";
+    ASSERT_TRUE(str.replace(1, 2, "BC") == "aBCd");
+    ASSERT_TRUE(str.replace(1, 2, bc) == "abcd");
+    ASSERT_TRUE(str.replace(1, 2, 'x') == "axd");
+    ASSERT_TRUE(str.replace(1, 1, std::string("bc")) == "abcd");
+    ASSERT_TRUE(str.replace(1, 2, cm::string_view("BC", 2)) == "aBCd");
+    ASSERT_TRUE(str.replace(1, 2, cm::String("bc")) == "abcd");
+  }
+  {
+    cm::String str = "abcd";
+    const char* bc = "bc";
+    ASSERT_TRUE(str.replace(str.begin() + 1, str.begin() + 3, "BC") == "aBCd");
+    ASSERT_TRUE(str.replace(str.begin() + 1, str.begin() + 3, bc) == "abcd");
+    ASSERT_TRUE(str.replace(str.begin() + 1, str.begin() + 3, 'x') == "axd");
+    ASSERT_TRUE(str.replace(str.begin() + 1, str.begin() + 2,
+                            std::string("bc")) == "abcd");
+    ASSERT_TRUE(str.replace(str.begin() + 1, str.begin() + 3,
+                            cm::string_view("BC", 2)) == "aBCd");
+    ASSERT_TRUE(str.replace(str.begin() + 1, str.begin() + 3,
+                            cm::String("bc")) == "abcd");
+  }
+  {
+    cm::String str = "abcd";
+    const char* bc = "_bc";
+    ASSERT_TRUE(str.replace(1, 2, "_BC_", 1, 2) == "aBCd");
+    ASSERT_TRUE(str.replace(1, 2, bc, 1) == "abcd");
+    ASSERT_TRUE(str.replace(1, 2, 'x', 0) == "axd");
+    ASSERT_TRUE(str.replace(1, 1, std::string("_bc_"), 1, 2) == "abcd");
+    ASSERT_TRUE(str.replace(1, 2, cm::string_view("_BC", 3), 1) == "aBCd");
+    ASSERT_TRUE(str.replace(1, 2, cm::String("_bc_"), 1, 2) == "abcd");
+  }
+  {
+    cm::String str = "abcd";
+    const char* bc = "_bc_";
+    ASSERT_TRUE(str.replace(1, 2, 2, 'x') == "axxd");
+    ASSERT_TRUE(str.replace(str.begin() + 1, str.begin() + 3, 2, 'y') ==
+                "ayyd");
+    ASSERT_TRUE(
+      str.replace(str.begin() + 1, str.begin() + 3, bc + 1, bc + 3) == "abcd");
+  }
+  return true;
+}
+
+static bool testMethod_copy()
+{
+  std::cout << "testMethod_copy()\n";
+  cm::String str = "abc";
+  char dest[2];
+  cm::String::size_type n = str.copy(dest, 2, 1);
+  ASSERT_TRUE(n == 2);
+  ASSERT_TRUE(std::strncmp(dest, "bc", 2) == 0);
+  n = str.copy(dest, 2);
+  ASSERT_TRUE(n == 2);
+  ASSERT_TRUE(std::strncmp(dest, "ab", 2) == 0);
+  return true;
+}
+
+static bool testMethod_resize()
+{
+  std::cout << "testMethod_resize()\n";
+  cm::String str = "abc";
+  str.resize(3);
+  ASSERT_TRUE(str == "abc");
+  str.resize(2);
+  ASSERT_TRUE(str == "ab");
+  str.resize(3, 'c');
+  ASSERT_TRUE(str == "abc");
+  return true;
+}
+
+static bool testMethod_swap()
+{
+  std::cout << "testMethod_swap()\n";
+  cm::String str1 = std::string("1");
+  cm::String str2 = std::string("2");
+  str1.swap(str2);
+  ASSERT_TRUE(str1 == "2");
+  ASSERT_TRUE(str2 == "1");
+  return true;
+}
+
+static bool testMethod_substr_AtEnd(cm::String str)
+{
+  cm::String substr = str.substr(1);
+  ASSERT_TRUE(substr.data() == str.data() + 1);
+  ASSERT_TRUE(substr.size() == 2);
+
+  // c_str() at the end of the buffer does not internally mutate.
+  ASSERT_TRUE(std::strcmp(substr.c_str(), "bc") == 0);
+  ASSERT_TRUE(substr.c_str() == str.data() + 1);
+  ASSERT_TRUE(substr.data() == str.data() + 1);
+  ASSERT_TRUE(substr.size() == 2);
+
+  // str() internally mutates.
+  ASSERT_TRUE(substr.str() == "bc");
+  ASSERT_TRUE(substr.data() != str.data() + 1);
+  ASSERT_TRUE(substr.size() == 2);
+  ASSERT_TRUE(substr.c_str() != str.data() + 1);
+  ASSERT_TRUE(std::strcmp(substr.c_str(), "bc") == 0);
+  return true;
+}
+
+static bool testMethod_substr_AtEndOwned()
+{
+  std::cout << "testMethod_substr_AtEndOwned()\n";
+  return testMethod_substr_AtEnd(std::string("abc"));
+}
+
+static bool testMethod_substr_AtStart(cm::String str)
+{
+  {
+    cm::String substr = str.substr(0, 2);
+    ASSERT_TRUE(substr.data() == str.data());
+    ASSERT_TRUE(substr.size() == 2);
+
+    // c_str() not at the end of the buffer internally mutates.
+    const char* substr_c = substr.c_str();
+    ASSERT_TRUE(std::strcmp(substr_c, "ab") == 0);
+    ASSERT_TRUE(substr_c != str.data());
+    ASSERT_TRUE(substr.data() != str.data());
+    ASSERT_TRUE(substr.size() == 2);
+
+    // str() does not need to internally mutate after c_str() did so
+    ASSERT_TRUE(substr.str() == "ab");
+    ASSERT_TRUE(substr.data() == substr_c);
+    ASSERT_TRUE(substr.size() == 2);
+    ASSERT_TRUE(substr.c_str() == substr_c);
+  }
+
+  {
+    cm::String substr = str.substr(0, 2);
+    ASSERT_TRUE(substr.data() == str.data());
+    ASSERT_TRUE(substr.size() == 2);
+
+    // str() internally mutates.
+    ASSERT_TRUE(substr.str() == "ab");
+    ASSERT_TRUE(substr.data() != str.data());
+    ASSERT_TRUE(substr.size() == 2);
+    ASSERT_TRUE(substr.c_str() != str.data());
+
+    // c_str() does not internally after str() did so
+    const char* substr_c = substr.c_str();
+    ASSERT_TRUE(std::strcmp(substr_c, "ab") == 0);
+    ASSERT_TRUE(substr_c == substr.data());
+    ASSERT_TRUE(substr.size() == 2);
+  }
+
+  return true;
+}
+
+static bool testMethod_substr_AtStartOwned()
+{
+  std::cout << "testMethod_substr_AtStartOwned()\n";
+  return testMethod_substr_AtStart(std::string("abc"));
+}
+
+static bool testMethod_compare()
+{
+  std::cout << "testMethod_compare()\n";
+  cm::String str = "b";
+  ASSERT_TRUE(str.compare("a") > 0);
+  ASSERT_TRUE(str.compare("b") == 0);
+  ASSERT_TRUE(str.compare("c") < 0);
+  {
+    const char* a = "a";
+    const char* b = "b";
+    const char* c = "c";
+    ASSERT_TRUE(str.compare(a) > 0);
+    ASSERT_TRUE(str.compare(b) == 0);
+    ASSERT_TRUE(str.compare(c) < 0);
+  }
+  ASSERT_TRUE(str.compare('a') > 0);
+  ASSERT_TRUE(str.compare('b') == 0);
+  ASSERT_TRUE(str.compare('c') < 0);
+  ASSERT_TRUE(str.compare(std::string("a")) > 0);
+  ASSERT_TRUE(str.compare(std::string("b")) == 0);
+  ASSERT_TRUE(str.compare(std::string("c")) < 0);
+  ASSERT_TRUE(str.compare(cm::string_view("a_", 1)) > 0);
+  ASSERT_TRUE(str.compare(cm::string_view("b_", 1)) == 0);
+  ASSERT_TRUE(str.compare(cm::string_view("c_", 1)) < 0);
+  ASSERT_TRUE(str.compare(cm::String("a")) > 0);
+  ASSERT_TRUE(str.compare(cm::String("b")) == 0);
+  ASSERT_TRUE(str.compare(cm::String("c")) < 0);
+  ASSERT_TRUE(str.compare(0, 1, cm::string_view("a", 1)) > 0);
+  ASSERT_TRUE(str.compare(1, 0, cm::string_view("", 0)) == 0);
+  ASSERT_TRUE(str.compare(0, 1, cm::string_view("ac", 2), 1, 1) < 0);
+  ASSERT_TRUE(str.compare(1, 0, "") == 0);
+  ASSERT_TRUE(str.compare(1, 0, "_", 0) == 0);
+  return true;
+}
+
+static bool testMethod_find()
+{
+  std::cout << "testMethod_find()\n";
+  cm::String str = "abcabc";
+  ASSERT_TRUE(str.find("a") == 0);
+  ASSERT_TRUE(str.find("a", 1) == 3);
+  {
+    const char* a = "a";
+    ASSERT_TRUE(str.find(a) == 0);
+    ASSERT_TRUE(str.find(a, 1) == 3);
+  }
+  ASSERT_TRUE(str.find('a') == 0);
+  ASSERT_TRUE(str.find('a', 1) == 3);
+  ASSERT_TRUE(str.find(std::string("a")) == 0);
+  ASSERT_TRUE(str.find(std::string("a"), 1) == 3);
+  ASSERT_TRUE(str.find(cm::string_view("a_", 1)) == 0);
+  ASSERT_TRUE(str.find(cm::string_view("a_", 1), 1) == 3);
+  ASSERT_TRUE(str.find(cm::String("a")) == 0);
+  ASSERT_TRUE(str.find(cm::String("a"), 1) == 3);
+  ASSERT_TRUE(str.find("ab_", 1, 2) == 3);
+  return true;
+}
+
+static bool testMethod_rfind()
+{
+  std::cout << "testMethod_rfind()\n";
+  cm::String str = "abcabc";
+  ASSERT_TRUE(str.rfind("a") == 3);
+  ASSERT_TRUE(str.rfind("a", 1) == 0);
+  {
+    const char* a = "a";
+    ASSERT_TRUE(str.rfind(a) == 3);
+    ASSERT_TRUE(str.rfind(a, 1) == 0);
+  }
+  ASSERT_TRUE(str.rfind('a') == 3);
+  ASSERT_TRUE(str.rfind('a', 1) == 0);
+  ASSERT_TRUE(str.rfind(std::string("a")) == 3);
+  ASSERT_TRUE(str.rfind(std::string("a"), 1) == 0);
+  ASSERT_TRUE(str.rfind(cm::string_view("a_", 1)) == 3);
+  ASSERT_TRUE(str.rfind(cm::string_view("a_", 1), 1) == 0);
+  ASSERT_TRUE(str.rfind(cm::String("a")) == 3);
+  ASSERT_TRUE(str.rfind(cm::String("a"), 1) == 0);
+  ASSERT_TRUE(str.rfind("ab_", 1, 2) == 0);
+  return true;
+}
+
+static bool testMethod_find_first_of()
+{
+  std::cout << "testMethod_find_first_of()\n";
+  cm::String str = "abcabc";
+  ASSERT_TRUE(str.find_first_of("_a") == 0);
+  ASSERT_TRUE(str.find_first_of("_a", 1) == 3);
+  {
+    const char* a = "_a";
+    ASSERT_TRUE(str.find_first_of(a) == 0);
+    ASSERT_TRUE(str.find_first_of(a, 1) == 3);
+  }
+  ASSERT_TRUE(str.find_first_of('a') == 0);
+  ASSERT_TRUE(str.find_first_of('a', 1) == 3);
+  ASSERT_TRUE(str.find_first_of(std::string("_a")) == 0);
+  ASSERT_TRUE(str.find_first_of(std::string("_a"), 1) == 3);
+  ASSERT_TRUE(str.find_first_of(cm::string_view("ba_", 1)) == 1);
+  ASSERT_TRUE(str.find_first_of(cm::string_view("ba_", 1), 2) == 4);
+  ASSERT_TRUE(str.find_first_of(cm::String("ab")) == 0);
+  ASSERT_TRUE(str.find_first_of(cm::String("ab"), 2) == 3);
+  ASSERT_TRUE(str.find_first_of("_ab", 1, 2) == 3);
+  return true;
+}
+
+static bool testMethod_find_first_not_of()
+{
+  std::cout << "testMethod_find_first_not_of()\n";
+  cm::String str = "abcabc";
+  ASSERT_TRUE(str.find_first_not_of("_a") == 1);
+  ASSERT_TRUE(str.find_first_not_of("_a", 2) == 2);
+  {
+    const char* a = "_a";
+    ASSERT_TRUE(str.find_first_not_of(a) == 1);
+    ASSERT_TRUE(str.find_first_not_of(a, 2) == 2);
+  }
+  ASSERT_TRUE(str.find_first_not_of('a') == 1);
+  ASSERT_TRUE(str.find_first_not_of('a', 2) == 2);
+  ASSERT_TRUE(str.find_first_not_of(std::string("_a")) == 1);
+  ASSERT_TRUE(str.find_first_not_of(std::string("_a"), 2) == 2);
+  ASSERT_TRUE(str.find_first_not_of(cm::string_view("ba_", 1)) == 0);
+  ASSERT_TRUE(str.find_first_not_of(cm::string_view("ba_", 1), 1) == 2);
+  ASSERT_TRUE(str.find_first_not_of(cm::String("_a")) == 1);
+  ASSERT_TRUE(str.find_first_not_of(cm::String("_a"), 2) == 2);
+  ASSERT_TRUE(str.find_first_not_of("_bca", 1, 3) == 3);
+  return true;
+}
+
+static bool testMethod_find_last_of()
+{
+  std::cout << "testMethod_find_last_of()\n";
+  cm::String str = "abcabc";
+  ASSERT_TRUE(str.find_last_of("_a") == 3);
+  ASSERT_TRUE(str.find_last_of("_a", 1) == 0);
+  {
+    const char* a = "_a";
+    ASSERT_TRUE(str.find_last_of(a) == 3);
+    ASSERT_TRUE(str.find_last_of(a, 1) == 0);
+  }
+  ASSERT_TRUE(str.find_last_of('a') == 3);
+  ASSERT_TRUE(str.find_last_of('a', 1) == 0);
+  ASSERT_TRUE(str.find_last_of(std::string("_a")) == 3);
+  ASSERT_TRUE(str.find_last_of(std::string("_a"), 1) == 0);
+  ASSERT_TRUE(str.find_last_of(cm::string_view("ba_", 1)) == 4);
+  ASSERT_TRUE(str.find_last_of(cm::string_view("ba_", 1), 2) == 1);
+  ASSERT_TRUE(str.find_last_of(cm::String("ab")) == 4);
+  ASSERT_TRUE(str.find_last_of(cm::String("ab"), 2) == 1);
+  ASSERT_TRUE(str.find_last_of("_ab", 1, 2) == 0);
+  return true;
+}
+
+static bool testMethod_find_last_not_of()
+{
+  std::cout << "testMethod_find_last_not_of()\n";
+  cm::String str = "abcabc";
+  ASSERT_TRUE(str.find_last_not_of("_a") == 5);
+  ASSERT_TRUE(str.find_last_not_of("_a", 1) == 1);
+  {
+    const char* a = "_a";
+    ASSERT_TRUE(str.find_last_not_of(a) == 5);
+    ASSERT_TRUE(str.find_last_not_of(a, 1) == 1);
+  }
+  ASSERT_TRUE(str.find_last_not_of('a') == 5);
+  ASSERT_TRUE(str.find_last_not_of('a', 1) == 1);
+  ASSERT_TRUE(str.find_last_not_of(std::string("_a")) == 5);
+  ASSERT_TRUE(str.find_last_not_of(std::string("_a"), 1) == 1);
+  ASSERT_TRUE(str.find_last_not_of(cm::string_view("cb_", 1)) == 4);
+  ASSERT_TRUE(str.find_last_not_of(cm::string_view("cb_", 1), 2) == 1);
+  ASSERT_TRUE(str.find_last_not_of(cm::String("_a")) == 5);
+  ASSERT_TRUE(str.find_last_not_of(cm::String("_a"), 1) == 1);
+  ASSERT_TRUE(str.find_last_not_of("cb_", 2, 2) == 0);
+  return true;
+}
+
+int testString(int /*unused*/, char* /*unused*/ [])
+{
+  if (!testConstructDefault()) {
+    return 1;
+  }
+  if (!testConstructFromNullPtr()) {
+    return 1;
+  }
+  if (!testConstructFromCStrNull()) {
+    return 1;
+  }
+  if (!testConstructFromCharArray()) {
+    return 1;
+  }
+  if (!testConstructFromCStr()) {
+    return 1;
+  }
+  if (!testConstructFromStdString()) {
+    return 1;
+  }
+  if (!testConstructFromView()) {
+    return 1;
+  }
+  if (!testConstructFromChar()) {
+    return 1;
+  }
+  if (!testConstructFromInitList()) {
+    return 1;
+  }
+  if (!testConstructFromBuffer()) {
+    return 1;
+  }
+  if (!testConstructFromInputIterator()) {
+    return 1;
+  }
+  if (!testConstructFromN()) {
+    return 1;
+  }
+  if (!testConstructCopy()) {
+    return 1;
+  }
+  if (!testConstructMove()) {
+    return 1;
+  }
+  if (!testAssignCopy()) {
+    return 1;
+  }
+  if (!testAssignMove()) {
+    return 1;
+  }
+  if (!testAssignFromChar()) {
+    return 1;
+  }
+  if (!testAssignFromView()) {
+    return 1;
+  }
+  if (!testAssignFromStdString()) {
+    return 1;
+  }
+  if (!testAssignFromCStr()) {
+    return 1;
+  }
+  if (!testAssignFromCharArray()) {
+    return 1;
+  }
+  if (!testAssignFromCStrNull()) {
+    return 1;
+  }
+  if (!testAssignFromNullPtr()) {
+    return 1;
+  }
+  if (!testAssignFromInitList()) {
+    return 1;
+  }
+  if (!testOperatorBool()) {
+    return 1;
+  }
+  if (!testOperatorIndex()) {
+    return 1;
+  }
+  if (!testOperatorPlusEqual()) {
+    return 1;
+  }
+  if (!testOperatorCompare()) {
+    return 1;
+  }
+  if (!testOperatorStream()) {
+    return 1;
+  }
+  if (!testOperatorStdStringPlusEqual()) {
+    return 1;
+  }
+  if (!testMethod_view()) {
+    return 1;
+  }
+  if (!testMethod_empty()) {
+    return 1;
+  }
+  if (!testMethod_length()) {
+    return 1;
+  }
+  if (!testMethod_at()) {
+    return 1;
+  }
+  if (!testMethod_front_back()) {
+    return 1;
+  }
+  if (!testMethod_clear()) {
+    return 1;
+  }
+  if (!testMethod_insert()) {
+    return 1;
+  }
+  if (!testMethod_erase()) {
+    return 1;
+  }
+  if (!testMethod_push_back()) {
+    return 1;
+  }
+  if (!testMethod_pop_back()) {
+    return 1;
+  }
+  if (!testMethod_replace()) {
+    return 1;
+  }
+  if (!testMethod_copy()) {
+    return 1;
+  }
+  if (!testMethod_resize()) {
+    return 1;
+  }
+  if (!testMethod_swap()) {
+    return 1;
+  }
+  if (!testMethodIterators()) {
+    return 1;
+  }
+  if (!testMethod_substr_AtEndOwned()) {
+    return 1;
+  }
+  if (!testMethod_substr_AtStartOwned()) {
+    return 1;
+  }
+  if (!testMethod_compare()) {
+    return 1;
+  }
+  if (!testMethod_find()) {
+    return 1;
+  }
+  if (!testMethod_rfind()) {
+    return 1;
+  }
+  if (!testMethod_find_first_of()) {
+    return 1;
+  }
+  if (!testMethod_find_first_not_of()) {
+    return 1;
+  }
+  if (!testMethod_find_last_of()) {
+    return 1;
+  }
+  if (!testMethod_find_last_not_of()) {
+    return 1;
+  }
+  return 0;
+}