gecko-dev/mfbt/TextUtils.h

57 строки
1.2 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* Character/text operations. */
#ifndef mozilla_TextUtils_h
#define mozilla_TextUtils_h
#include "mozilla/TypeTraits.h"
namespace mozilla {
namespace detail {
template<typename Char>
class MakeUnsignedChar
: public MakeUnsigned<Char>
{};
template<>
class MakeUnsignedChar<char16_t>
{
public:
using Type = char16_t;
};
template<>
class MakeUnsignedChar<char32_t>
{
public:
using Type = char32_t;
};
} // namespace detail
/**
* Returns true iff |aChar| matches [a-zA-Z].
*
* This function is basically what you thought isalpha was, except its behavior
* doesn't depend on the user's current locale.
*/
template<typename Char>
constexpr bool
IsAsciiAlpha(Char aChar)
{
using UnsignedChar = typename detail::MakeUnsignedChar<Char>::Type;
auto uc = static_cast<UnsignedChar>(aChar);
return ('a' <= uc && uc <= 'z') || ('A' <= uc && uc <= 'Z');
}
} // namespace mozilla
#endif /* mozilla_TextUtils_h */