uses_allocator.h
// Uses-allocator Construction -*- C++ -*-
// Copyright (C) 2010-2013 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();
_GLIBCXX_HAS_NESTED_TYPE(allocator_type)
template<typename _Tp, typename _Alloc,
bool = __has_allocator_type<_Tp>::value>
struct __uses_allocator_helper
: public false_type { };
template<typename _Tp, typename _Alloc>
struct __uses_allocator_helper<_Tp, _Alloc, true>
: public integral_constant<bool, is_convertible<_Alloc,
typename _Tp::allocator_type>::value>
{ };
/// [allocator.uses.trait]
template<typename _Tp, typename _Alloc>
struct uses_allocator
: public integral_constant<bool,
__uses_allocator_helper<_Tp, _Alloc>::value>
{ };
template<typename _Tp, typename _Alloc, typename... _Args>
struct __uses_allocator_arg
: is_constructible<_Tp, _Alloc, _Args...>
{ static_assert( uses_allocator<_Tp, _Alloc>::value, "uses allocator" ); };
struct __uses_alloc_base { };
struct __uses_alloc0 : __uses_alloc_base
{ struct _Anything { _Anything(...) { } } _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 _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>
struct __uses_alloc_impl
: __uses_alloc<uses_allocator<_Tp, _Alloc>::value, _Tp, _Alloc, _Args...>
{ };
template<typename _Tp, typename _Alloc, typename... _Args>
__uses_alloc_impl<_Tp, _Alloc, _Args...>
__use_alloc(const _Alloc& __a)
{
__uses_alloc_impl<_Tp, _Alloc, _Args...> __ret;
__ret._M_a = &__a;
return __ret;
}
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
#endif
#endif