libstdc++
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00001 // Uses-allocator Construction -*- C++ -*- 00002 00003 // Copyright (C) 2010-2015 Free Software Foundation, Inc. 00004 // 00005 // This file is part of the GNU ISO C++ Library. This library is free 00006 // software; you can redistribute it and/or modify it under the 00007 // terms of the GNU General Public License as published by the 00008 // Free Software Foundation; either version 3, or (at your option) 00009 // any later version. 00010 00011 // This library is distributed in the hope that it will be useful, 00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00014 // GNU General Public License for more details. 00015 00016 // Under Section 7 of GPL version 3, you are granted additional 00017 // permissions described in the GCC Runtime Library Exception, version 00018 // 3.1, as published by the Free Software Foundation. 00019 00020 // You should have received a copy of the GNU General Public License and 00021 // a copy of the GCC Runtime Library Exception along with this program; 00022 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 00023 // <http://www.gnu.org/licenses/>. 00024 00025 #ifndef _USES_ALLOCATOR_H 00026 #define _USES_ALLOCATOR_H 1 00027 00028 #if __cplusplus < 201103L 00029 # include <bits/c++0x_warning.h> 00030 #else 00031 00032 #include <type_traits> 00033 00034 namespace std _GLIBCXX_VISIBILITY(default) 00035 { 00036 _GLIBCXX_BEGIN_NAMESPACE_VERSION 00037 00038 /// [allocator.tag] 00039 struct allocator_arg_t { }; 00040 00041 constexpr allocator_arg_t allocator_arg = allocator_arg_t(); 00042 00043 template<typename _Tp, typename _Alloc, typename = __void_t<>> 00044 struct __uses_allocator_helper 00045 : false_type { }; 00046 00047 template<typename _Tp, typename _Alloc> 00048 struct __uses_allocator_helper<_Tp, _Alloc, 00049 __void_t<typename _Tp::allocator_type>> 00050 : is_convertible<_Alloc, typename _Tp::allocator_type>::type 00051 { }; 00052 00053 /// [allocator.uses.trait] 00054 template<typename _Tp, typename _Alloc> 00055 struct uses_allocator 00056 : __uses_allocator_helper<_Tp, _Alloc>::type 00057 { }; 00058 00059 struct __uses_alloc_base { }; 00060 00061 struct __uses_alloc0 : __uses_alloc_base 00062 { 00063 struct _Sink { void operator=(const void*) { } } _M_a; 00064 }; 00065 00066 template<typename _Alloc> 00067 struct __uses_alloc1 : __uses_alloc_base { const _Alloc* _M_a; }; 00068 00069 template<typename _Alloc> 00070 struct __uses_alloc2 : __uses_alloc_base { const _Alloc* _M_a; }; 00071 00072 template<bool, typename _Tp, typename _Alloc, typename... _Args> 00073 struct __uses_alloc; 00074 00075 template<typename _Tp, typename _Alloc, typename... _Args> 00076 struct __uses_alloc<true, _Tp, _Alloc, _Args...> 00077 : conditional< 00078 is_constructible<_Tp, allocator_arg_t, _Alloc, _Args...>::value, 00079 __uses_alloc1<_Alloc>, 00080 __uses_alloc2<_Alloc>>::type 00081 { }; 00082 00083 template<typename _Tp, typename _Alloc, typename... _Args> 00084 struct __uses_alloc<false, _Tp, _Alloc, _Args...> 00085 : __uses_alloc0 { }; 00086 00087 template<typename _Tp, typename _Alloc, typename... _Args> 00088 using __uses_alloc_t = 00089 __uses_alloc<uses_allocator<_Tp, _Alloc>::value, _Tp, _Alloc, _Args...>; 00090 00091 template<typename _Tp, typename _Alloc, typename... _Args> 00092 inline __uses_alloc_t<_Tp, _Alloc, _Args...> 00093 __use_alloc(const _Alloc& __a) 00094 { 00095 __uses_alloc_t<_Tp, _Alloc, _Args...> __ret; 00096 __ret._M_a = &__a; 00097 return __ret; 00098 } 00099 00100 _GLIBCXX_END_NAMESPACE_VERSION 00101 } // namespace std 00102 00103 #endif 00104 #endif