| // -*- C++ -*- |
| |
| // Copyright (C) 2005, 2006, 2007, 2009 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 3, 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. |
| |
| // Under Section 7 of GPL version 3, you are granted additional |
| // permissions described in the GCC Runtime Library Exception, version |
| // 3.1, as published by the Free Software Foundation. |
| |
| // You should have received a copy of the GNU General Public License and |
| // a copy of the GCC Runtime Library Exception along with this program; |
| // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| // <http://www.gnu.org/licenses/>. |
| |
| /** @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 <bits/c++config.h> |
| #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>; |
| |
| |
| // For use in string and vstring. |
| template<typename _Type> |
| inline bool |
| __is_null_pointer(_Type* __ptr) |
| { return __ptr == 0; } |
| |
| template<typename _Type> |
| inline bool |
| __is_null_pointer(_Type) |
| { return false; } |
| |
| |
| // For complex and cmath |
| template<typename _Tp, bool = std::__is_integer<_Tp>::__value> |
| struct __promote |
| { typedef double __type; }; |
| |
| template<typename _Tp> |
| struct __promote<_Tp, false> |
| { typedef _Tp __type; }; |
| |
| template<typename _Tp, typename _Up> |
| struct __promote_2 |
| { |
| private: |
| typedef typename __promote<_Tp>::__type __type1; |
| typedef typename __promote<_Up>::__type __type2; |
| |
| public: |
| typedef __typeof__(__type1() + __type2()) __type; |
| }; |
| |
| template<typename _Tp, typename _Up, typename _Vp> |
| struct __promote_3 |
| { |
| private: |
| typedef typename __promote<_Tp>::__type __type1; |
| typedef typename __promote<_Up>::__type __type2; |
| typedef typename __promote<_Vp>::__type __type3; |
| |
| public: |
| typedef __typeof__(__type1() + __type2() + __type3()) __type; |
| }; |
| |
| template<typename _Tp, typename _Up, typename _Vp, typename _Wp> |
| struct __promote_4 |
| { |
| private: |
| typedef typename __promote<_Tp>::__type __type1; |
| typedef typename __promote<_Up>::__type __type2; |
| typedef typename __promote<_Vp>::__type __type3; |
| typedef typename __promote<_Wp>::__type __type4; |
| |
| public: |
| typedef __typeof__(__type1() + __type2() + __type3() + __type4()) __type; |
| }; |
| |
| _GLIBCXX_END_NAMESPACE |
| |
| #endif |