src/base/strings/string_util.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.
//
// This file defines utility functions for working with strings.

#ifndef BASE_STRINGS_STRING_UTIL_H_
#define BASE_STRINGS_STRING_UTIL_H_

#include <ctype.h>
#include <stdarg.h>   // va_list
#include <stddef.h>
#include <stdint.h>

#include <string>
#include <vector>

#include "base/strings/string16.h"
#include "base/strings/string_piece.h"  // For implicit conversions.
#include "build/build_config.h"

#define BASE_EXPORT

namespace url {
namespace base {

// ASCII-specific tolower.  The standard library's tolower is locale sensitive,
// so we don't want to use it here.
inline char ToLowerASCII(char c) {
  return (c >= 'A' && c <= 'Z') ? (c + ('a' - 'A')) : c;
}
inline char16 ToLowerASCII(char16 c) {
  return (c >= 'A' && c <= 'Z') ? (c + ('a' - 'A')) : c;
}

// Converts the given string to it's ASCII-lowercase equivalent.
BASE_EXPORT std::string ToLowerASCII(StringPiece str);
BASE_EXPORT string16 ToLowerASCII(StringPiece16 str);

BASE_EXPORT bool IsStringASCII(const StringPiece& str);
BASE_EXPORT bool IsStringASCII(const StringPiece16& str);
BASE_EXPORT bool IsStringASCII(const string16& str);
#if defined(WCHAR_T_IS_UTF32)
BASE_EXPORT bool IsStringASCII(const std::wstring& str);
#endif

// Compare the lower-case form of the given string against the given
// previously-lower-cased ASCII string (typically a constant).
BASE_EXPORT bool LowerCaseEqualsASCII(StringPiece str,
                                      StringPiece lowecase_ascii);
BASE_EXPORT bool LowerCaseEqualsASCII(StringPiece16 str,
                                      StringPiece lowecase_ascii);

template <typename Char>
inline bool IsAsciiAlpha(Char c) {
  return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
}
template <typename Char>
inline bool IsAsciiLower(Char c) {
  return c >= 'a' && c <= 'z';
}

}  // namespace base
}  // namespace url

#endif  // BASE_STRINGS_STRING_UTIL_H_