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Diffstat (limited to 'libstdc++-v3/include/ext/type_traits.h')
| -rw-r--r-- | libstdc++-v3/include/ext/type_traits.h | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/libstdc++-v3/include/ext/type_traits.h b/libstdc++-v3/include/ext/type_traits.h new file mode 100644 index 000000000..51db03ec7 --- /dev/null +++ b/libstdc++-v3/include/ext/type_traits.h @@ -0,0 +1,214 @@ +// -*- C++ -*- + +// Copyright (C) 2005, 2006, 2007, 2009, 2010, 2011 +// 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> + +namespace __gnu_cxx _GLIBCXX_VISIBILITY(default) +{ +_GLIBCXX_BEGIN_NAMESPACE_VERSION + + // 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; }; + + // No nested __type member for non-integer non-floating point types, + // allows this type to be used for SFINAE to constrain overloads in + // <cmath> and <complex> to only the intended types. + template<typename _Tp> + struct __promote<_Tp, false> + { }; + + template<> + struct __promote<long double> + { typedef long double __type; }; + + template<> + struct __promote<double> + { typedef double __type; }; + + template<> + struct __promote<float> + { typedef float __type; }; + + template<typename _Tp, typename _Up, + typename _Tp2 = typename __promote<_Tp>::__type, + typename _Up2 = typename __promote<_Up>::__type> + struct __promote_2 + { + typedef __typeof__(_Tp2() + _Up2()) __type; + }; + + template<typename _Tp, typename _Up, typename _Vp, + typename _Tp2 = typename __promote<_Tp>::__type, + typename _Up2 = typename __promote<_Up>::__type, + typename _Vp2 = typename __promote<_Vp>::__type> + struct __promote_3 + { + typedef __typeof__(_Tp2() + _Up2() + _Vp2()) __type; + }; + + template<typename _Tp, typename _Up, typename _Vp, typename _Wp, + typename _Tp2 = typename __promote<_Tp>::__type, + typename _Up2 = typename __promote<_Up>::__type, + typename _Vp2 = typename __promote<_Vp>::__type, + typename _Wp2 = typename __promote<_Wp>::__type> + struct __promote_4 + { + typedef __typeof__(_Tp2() + _Up2() + _Vp2() + _Wp2()) __type; + }; + +_GLIBCXX_END_NAMESPACE_VERSION +} // namespace + +#endif |