base/strings/string16.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/strings/string16.h"
   6
   7 #if defined(WCHAR_T_IS_UTF16)
   8
   9 #error This file should not be used on 2-byte wchar_t systems
  10 // If this winds up being needed on 2-byte wchar_t systems, either the
  11 // definitions below can be used, or the host system's wide character
  12 // functions like wmemcmp can be wrapped.
  13
  14 #elif defined(WCHAR_T_IS_UTF32)
  15
  16 #include <ostream>
  17
  18 #include "base/strings/utf_string_conversions.h"
  19
  20 namespace base {
  21
  22 int c16memcmp(const char16* s1, const char16* s2, size_t n) {
  23   // We cannot call memcmp because that changes the semantics.
  24   while (n-- > 0) {
  25     if (*s1 != *s2) {
  26       // We cannot use (*s1 - *s2) because char16 is unsigned.
  27       return ((*s1 < *s2) ? -1 : 1);
  28     }
  29     ++s1;
  30     ++s2;
  31   }
  32   return 0;
  33 }
  34
  35 size_t c16len(const char16* s) {
  36   const char16 *s_orig = s;
  37   while (*s) {
  38     ++s;
  39   }
  40   return s - s_orig;
  41 }
  42
  43 const char16* c16memchr(const char16* s, char16 c, size_t n) {
  44   while (n-- > 0) {
  45     if (*s == c) {
  46       return s;
  47     }
  48     ++s;
  49   }
  50   return 0;
  51 }
  52
  53 char16* c16memmove(char16* s1, const char16* s2, size_t n) {
  54   return static_cast<char16*>(memmove(s1, s2, n * sizeof(char16)));
  55 }
  56
  57 char16* c16memcpy(char16* s1, const char16* s2, size_t n) {
  58   return static_cast<char16*>(memcpy(s1, s2, n * sizeof(char16)));
  59 }
  60
  61 char16* c16memset(char16* s, char16 c, size_t n) {
  62   char16 *s_orig = s;
  63   while (n-- > 0) {
  64     *s = c;
  65     ++s;
  66   }
  67   return s_orig;
  68 }
  69
  70 std::ostream& operator<<(std::ostream& out, const string16& str) {
  71   return out << UTF16ToUTF8(str);
  72 }
  73
  74 void PrintTo(const string16& str, std::ostream* out) {
  75   *out << str;
  76 }
  77
  78 }  // namespace base
  79
  80 template class std::basic_string<char16, base::string16_char_traits>;
  81
  82 #endif  // WCHAR_T_IS_UTF32