| // Uses-allocator Construction -*- C++ -*- |
| |
| // Copyright (C) 2010-2015 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/>. |
| |
| #ifndef _USES_ALLOCATOR_H |
| #define _USES_ALLOCATOR_H 1 |
| |
| #if __cplusplus < 201103L |
| # include <bits/c++0x_warning.h> |
| #else |
| |
| #include <type_traits> |
| |
| namespace std _GLIBCXX_VISIBILITY(default) |
| { |
| _GLIBCXX_BEGIN_NAMESPACE_VERSION |
| |
| /// [allocator.tag] |
| struct allocator_arg_t { }; |
| |
| constexpr allocator_arg_t allocator_arg = allocator_arg_t(); |
| |
| template<typename _Tp, typename _Alloc, typename = __void_t<>> |
| struct __uses_allocator_helper |
| : false_type { }; |
| |
| template<typename _Tp, typename _Alloc> |
| struct __uses_allocator_helper<_Tp, _Alloc, |
| __void_t<typename _Tp::allocator_type>> |
| : is_convertible<_Alloc, typename _Tp::allocator_type>::type |
| { }; |
| |
| /// [allocator.uses.trait] |
| template<typename _Tp, typename _Alloc> |
| struct uses_allocator |
| : __uses_allocator_helper<_Tp, _Alloc>::type |
| { }; |
| |
| struct __uses_alloc_base { }; |
| |
| struct __uses_alloc0 : __uses_alloc_base |
| { |
| struct _Sink { void operator=(const void*) { } } _M_a; |
| }; |
| |
| template<typename _Alloc> |
| struct __uses_alloc1 : __uses_alloc_base { const _Alloc* _M_a; }; |
| |
| template<typename _Alloc> |
| struct __uses_alloc2 : __uses_alloc_base { const _Alloc* _M_a; }; |
| |
| template<bool, typename _Tp, typename _Alloc, typename... _Args> |
| struct __uses_alloc; |
| |
| template<typename _Tp, typename _Alloc, typename... _Args> |
| struct __uses_alloc<true, _Tp, _Alloc, _Args...> |
| : conditional< |
| is_constructible<_Tp, allocator_arg_t, _Alloc, _Args...>::value, |
| __uses_alloc1<_Alloc>, |
| __uses_alloc2<_Alloc>>::type |
| { }; |
| |
| template<typename _Tp, typename _Alloc, typename... _Args> |
| struct __uses_alloc<false, _Tp, _Alloc, _Args...> |
| : __uses_alloc0 { }; |
| |
| template<typename _Tp, typename _Alloc, typename... _Args> |
| using __uses_alloc_t = |
| __uses_alloc<uses_allocator<_Tp, _Alloc>::value, _Tp, _Alloc, _Args...>; |
| |
| template<typename _Tp, typename _Alloc, typename... _Args> |
| inline __uses_alloc_t<_Tp, _Alloc, _Args...> |
| __use_alloc(const _Alloc& __a) |
| { |
| __uses_alloc_t<_Tp, _Alloc, _Args...> __ret; |
| __ret._M_a = &__a; |
| return __ret; |
| } |
| |
| _GLIBCXX_END_NAMESPACE_VERSION |
| } // namespace std |
| |
| #endif |
| #endif |