base/strings/string16.h

// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef BASE_STRINGS_STRING16_H_
#define BASE_STRINGS_STRING16_H_

// WHAT:
// Type aliases for string and character types supporting UTF-16 data. Prior to
// C++11 there was no standard library solution for this, which is why wstring
// was used where possible (i.e. where wchar_t holds UTF-16 encoded data).
//
// In C++11 we gained std::u16string, which is a cross-platform solution for
// UTF-16 strings. This is now the string16 type where ever wchar_t does not
// hold UTF16 data (i.e. commonly non-Windows platforms). Eventually this should
// be used everywhere, at which point this type alias and this file should be
// removed. https://crbug.com/911896 tracks the migration effort.

#include <string>

#include "build/build_config.h"

#if defined(WCHAR_T_IS_UTF16)

// Define a macro for wrapping construction of char16 arrays and string16s from
// a literal string. This indirection allows for an easier migration of
// gurl_base::char16 to char16_t on platforms where WCHAR_T_IS_UTF16, as only a one
// character change to the macro will be necessary.
// TODO(https://crbug.com/911896): Remove this macro once gurl_base::char16 is
// char16_t on all platforms.
#define STRING16_LITERAL(x) L##x

namespace gurl_base {
using char16 = wchar_t;
using string16 = std::wstring;
}  // namespace base

#else

#define STRING16_LITERAL(x) u##x

namespace gurl_base {
using char16 = char16_t;
using string16 = std::u16string;
}  // namespace base

#endif  // WCHAR_T_IS_UTF16

#endif  // BASE_STRINGS_STRING16_H_