| // -*- C++ -*- |
| |
| // Copyright (C) 2005, 2006, 2007 Free Software Foundation, Inc. |
| // |
| // This file is part of the GNU ISO C++ Library. This library is free |
| // software; you can redistribute it and/or modify it under the terms |
| // of the GNU General Public License as published by the Free Software |
| // Foundation; either version 2, or (at your option) any later |
| // version. |
| |
| // This library is distributed in the hope that it will be useful, but |
| // WITHOUT ANY WARRANTY; without even the implied warranty of |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| // General Public License for more details. |
| |
| // You should have received a copy of the GNU General Public License along |
| // with this library; see the file COPYING. If not, write to the Free |
| // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, |
| // USA. |
| |
| // As a special exception, you may use this file as part of a free |
| // software library without restriction. Specifically, if other files |
| // instantiate templates or use macros or inline functions from this |
| // file, or you compile this file and link it with other files to |
| // produce an executable, this file does not by itself cause the |
| // resulting executable to be covered by the GNU General Public |
| // License. This exception does not however invalidate any other |
| // reasons why the executable file might be covered by the GNU General |
| // Public License. |
| |
| /** @file ext/type_traits.h |
| * This file is a GNU extension to the Standard C++ Library. |
| */ |
| |
| #ifndef _EXT_TYPE_TRAITS |
| #define _EXT_TYPE_TRAITS 1 |
| |
| #pragma GCC system_header |
| |
| #include <cstddef> |
| #include <utility> |
| #include <bits/cpp_type_traits.h> |
| |
| _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx) |
| |
| // Define a nested type if some predicate holds. |
| template<bool, typename> |
| struct __enable_if |
| { }; |
| |
| template<typename _Tp> |
| struct __enable_if<true, _Tp> |
| { typedef _Tp __type; }; |
| |
| |
| // Conditional expression for types. If true, first, if false, second. |
| template<bool _Cond, typename _Iftrue, typename _Iffalse> |
| struct __conditional_type |
| { typedef _Iftrue __type; }; |
| |
| template<typename _Iftrue, typename _Iffalse> |
| struct __conditional_type<false, _Iftrue, _Iffalse> |
| { typedef _Iffalse __type; }; |
| |
| |
| // Given an integral builtin type, return the corresponding unsigned type. |
| template<typename _Tp> |
| struct __add_unsigned |
| { |
| private: |
| typedef __enable_if<std::__is_integer<_Tp>::__value, _Tp> __if_type; |
| |
| public: |
| typedef typename __if_type::__type __type; |
| }; |
| |
| template<> |
| struct __add_unsigned<char> |
| { typedef unsigned char __type; }; |
| |
| template<> |
| struct __add_unsigned<signed char> |
| { typedef unsigned char __type; }; |
| |
| template<> |
| struct __add_unsigned<short> |
| { typedef unsigned short __type; }; |
| |
| template<> |
| struct __add_unsigned<int> |
| { typedef unsigned int __type; }; |
| |
| template<> |
| struct __add_unsigned<long> |
| { typedef unsigned long __type; }; |
| |
| template<> |
| struct __add_unsigned<long long> |
| { typedef unsigned long long __type; }; |
| |
| // Declare but don't define. |
| template<> |
| struct __add_unsigned<bool>; |
| |
| template<> |
| struct __add_unsigned<wchar_t>; |
| |
| |
| // Given an integral builtin type, return the corresponding signed type. |
| template<typename _Tp> |
| struct __remove_unsigned |
| { |
| private: |
| typedef __enable_if<std::__is_integer<_Tp>::__value, _Tp> __if_type; |
| |
| public: |
| typedef typename __if_type::__type __type; |
| }; |
| |
| template<> |
| struct __remove_unsigned<char> |
| { typedef signed char __type; }; |
| |
| template<> |
| struct __remove_unsigned<unsigned char> |
| { typedef signed char __type; }; |
| |
| template<> |
| struct __remove_unsigned<unsigned short> |
| { typedef short __type; }; |
| |
| template<> |
| struct __remove_unsigned<unsigned int> |
| { typedef int __type; }; |
| |
| template<> |
| struct __remove_unsigned<unsigned long> |
| { typedef long __type; }; |
| |
| template<> |
| struct __remove_unsigned<unsigned long long> |
| { typedef long long __type; }; |
| |
| // Declare but don't define. |
| template<> |
| struct __remove_unsigned<bool>; |
| |
| template<> |
| struct __remove_unsigned<wchar_t>; |
| |
| _GLIBCXX_END_NAMESPACE |
| |
| #endif |