libstdc++
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00001 // Uses-allocator Construction -*- C++ -*- 00002 00003 // Copyright (C) 2010, 2011 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 #ifndef __GXX_EXPERIMENTAL_CXX0X__ 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 _GLIBCXX_HAS_NESTED_TYPE(allocator_type) 00044 00045 template<typename _Tp, typename _Alloc, 00046 bool = __has_allocator_type<_Tp>::value> 00047 struct __uses_allocator_helper 00048 : public false_type { }; 00049 00050 template<typename _Tp, typename _Alloc> 00051 struct __uses_allocator_helper<_Tp, _Alloc, true> 00052 : public integral_constant<bool, is_convertible<_Alloc, 00053 typename _Tp::allocator_type>::value> 00054 { }; 00055 00056 /// [allocator.uses.trait] 00057 template<typename _Tp, typename _Alloc> 00058 struct uses_allocator 00059 : public integral_constant<bool, 00060 __uses_allocator_helper<_Tp, _Alloc>::value> 00061 { }; 00062 00063 template<typename _Tp, typename _Alloc, typename... _Args> 00064 struct __uses_allocator_arg 00065 : is_constructible<_Tp, _Alloc, _Args...> 00066 { static_assert( uses_allocator<_Tp, _Alloc>::value, "uses allocator" ); }; 00067 00068 struct __uses_alloc_base { }; 00069 struct __uses_alloc0 : __uses_alloc_base 00070 { struct _Anything { _Anything(...) { } } _M_a; }; 00071 template<typename _Alloc> 00072 struct __uses_alloc1 : __uses_alloc_base { const _Alloc* _M_a; }; 00073 template<typename _Alloc> 00074 struct __uses_alloc2 : __uses_alloc_base { const _Alloc* _M_a; }; 00075 00076 template<bool, typename _Alloc, typename... _Args> 00077 struct __uses_alloc; 00078 00079 template<typename _Tp, typename _Alloc, typename... _Args> 00080 struct __uses_alloc<true, _Tp, _Alloc, _Args...> 00081 : conditional< 00082 is_constructible<_Tp, allocator_arg_t, _Alloc, _Args...>::value, 00083 __uses_alloc1<_Alloc>, 00084 __uses_alloc2<_Alloc>>::type 00085 { }; 00086 00087 template<typename _Tp, typename _Alloc, typename... _Args> 00088 struct __uses_alloc<false, _Tp, _Alloc, _Args...> 00089 : __uses_alloc0 { }; 00090 00091 template<typename _Tp, typename _Alloc, typename... _Args> 00092 struct __uses_alloc_impl 00093 : __uses_alloc<uses_allocator<_Tp, _Alloc>::value, _Tp, _Alloc, _Args...> 00094 { }; 00095 00096 template<typename _Tp, typename _Alloc, typename... _Args> 00097 __uses_alloc_impl<_Tp, _Alloc, _Args...> 00098 __use_alloc(const _Alloc& __a) 00099 { 00100 __uses_alloc_impl<_Tp, _Alloc, _Args...> __ret; 00101 __ret._M_a = &__a; 00102 return __ret; 00103 } 00104 00105 _GLIBCXX_END_NAMESPACE_VERSION 00106 } // namespace std 00107 00108 #endif 00109 #endif