base/utf_string_conversions.h

// Copyright (c) 2009 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_UTF_STRING_CONVERSIONS_H_
#define BASE_UTF_STRING_CONVERSIONS_H_
#pragma once

#include <string>

#include "base/string16.h"

namespace base {
class StringPiece;
}

// These convert between UTF-8, -16, and -32 strings. They are potentially slow,
// so avoid unnecessary conversions. The low-level versions return a boolean
// indicating whether the conversion was 100% valid. In this case, it will still
// do the best it can and put the result in the output buffer. The versions that
// return strings ignore this error and just return the best conversion
// possible.
bool WideToUTF8(const wchar_t* src, size_t src_len, std::string* output);
std::string WideToUTF8(const std::wstring& wide);
bool UTF8ToWide(const char* src, size_t src_len, std::wstring* output);
std::wstring UTF8ToWide(const base::StringPiece& utf8);

bool WideToUTF16(const wchar_t* src, size_t src_len, string16* output);
string16 WideToUTF16(const std::wstring& wide);
bool UTF16ToWide(const char16* src, size_t src_len, std::wstring* output);
std::wstring UTF16ToWide(const string16& utf16);

bool UTF8ToUTF16(const char* src, size_t src_len, string16* output);
string16 UTF8ToUTF16(const std::string& utf8);
bool UTF16ToUTF8(const char16* src, size_t src_len, std::string* output);
std::string UTF16ToUTF8(const string16& utf16);

// We are trying to get rid of wstring as much as possible, but it's too big
// a mess to do it all at once.  These conversions should be used when we
// really should just be passing a string16 around, but we haven't finished
// porting whatever module uses wstring and the conversion is being used as a
// stopcock.  This makes it easy to grep for the ones that should be removed.
#if defined(OS_WIN)
# define WideToUTF16Hack
# define UTF16ToWideHack
#else
# define WideToUTF16Hack WideToUTF16
# define UTF16ToWideHack UTF16ToWide
#endif

// These convert an ASCII string, typically a hardcoded constant, to a
// UTF16/Wide string.
//
// Note that this doesn't use StringPiece because it's very common to need
// ASCIIToUTF16("foo"), and either we have to include it in this file, or
// forward declare it and force all callers to include string_piece.h. Given
// that string_piece brings in complicated stuff like <algorithm>, it's
// easier to just duplicate these very simple definitions for the two calling
// cases we actually use.
std::wstring ASCIIToWide(const char* ascii);
std::wstring ASCIIToWide(const std::string& ascii);
string16 ASCIIToUTF16(const char* ascii);
string16 ASCIIToUTF16(const std::string& ascii);

#endif  // BASE_UTF_STRING_CONVERSIONS_H_