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// Uses-allocator Construction -*- C++ -*- |
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// Copyright (C) 2010-2021 Free Software Foundation, Inc. |
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// |
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// This file is part of the GNU ISO C++ Library. This library is free |
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// software; you can redistribute it and/or modify it under the |
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// terms of the GNU General Public License as published by the |
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// Free Software Foundation; either version 3, or (at your option) |
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// any later version. |
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|
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// This library is distributed in the hope that it will be useful, |
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// but WITHOUT ANY WARRANTY; without even the implied warranty of |
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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// GNU General Public License for more details. |
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|
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// Under Section 7 of GPL version 3, you are granted additional |
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// permissions described in the GCC Runtime Library Exception, version |
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// 3.1, as published by the Free Software Foundation. |
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|
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// You should have received a copy of the GNU General Public License and |
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// a copy of the GCC Runtime Library Exception along with this program; |
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// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
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// <http://www.gnu.org/licenses/>. |
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|
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#ifndef _USES_ALLOCATOR_H |
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#define _USES_ALLOCATOR_H 1 |
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|
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#if __cplusplus < 201103L |
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# include <bits/c++0x_warning.h> |
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#else |
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|
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#include <type_traits> |
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#include <bits/move.h> |
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|
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namespace std _GLIBCXX_VISIBILITY(default) |
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{ |
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_GLIBCXX_BEGIN_NAMESPACE_VERSION |
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|
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// This is used for std::experimental::erased_type from Library Fundamentals. |
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struct __erased_type { }; |
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|
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// This also supports the "type-erased allocator" protocol from the |
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// Library Fundamentals TS, where allocator_type is erased_type. |
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// The second condition will always be false for types not using the TS. |
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template<typename _Alloc, typename _Tp> |
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using __is_erased_or_convertible |
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= __or_<is_convertible<_Alloc, _Tp>, is_same<_Tp, __erased_type>>; |
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|
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/// [allocator.tag] |
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struct allocator_arg_t { explicit allocator_arg_t() = default; }; |
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|
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_GLIBCXX17_INLINE constexpr allocator_arg_t allocator_arg = |
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allocator_arg_t(); |
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|
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template<typename _Tp, typename _Alloc, typename = __void_t<>> |
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struct __uses_allocator_helper |
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: false_type { }; |
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|
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template<typename _Tp, typename _Alloc> |
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struct __uses_allocator_helper<_Tp, _Alloc, |
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__void_t<typename _Tp::allocator_type>> |
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: __is_erased_or_convertible<_Alloc, typename _Tp::allocator_type>::type |
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{ }; |
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|
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/// [allocator.uses.trait] |
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template<typename _Tp, typename _Alloc> |
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struct uses_allocator |
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: __uses_allocator_helper<_Tp, _Alloc>::type |
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{ }; |
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|
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struct __uses_alloc_base { }; |
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|
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struct __uses_alloc0 : __uses_alloc_base |
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{ |
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struct _Sink { void _GLIBCXX20_CONSTEXPR operator=(const void*) { } } _M_a; |
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}; |
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|
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template<typename _Alloc> |
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struct __uses_alloc1 : __uses_alloc_base { const _Alloc* _M_a; }; |
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|
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template<typename _Alloc> |
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struct __uses_alloc2 : __uses_alloc_base { const _Alloc* _M_a; }; |
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|
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template<bool, typename _Tp, typename _Alloc, typename... _Args> |
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struct __uses_alloc; |
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|
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template<typename _Tp, typename _Alloc, typename... _Args> |
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struct __uses_alloc<true, _Tp, _Alloc, _Args...> |
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: conditional< |
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is_constructible<_Tp, allocator_arg_t, const _Alloc&, _Args...>::value, |
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__uses_alloc1<_Alloc>, |
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__uses_alloc2<_Alloc>>::type |
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{ |
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// _GLIBCXX_RESOLVE_LIB_DEFECTS |
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// 2586. Wrong value category used in scoped_allocator_adaptor::construct |
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static_assert(__or_< |
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is_constructible<_Tp, allocator_arg_t, const _Alloc&, _Args...>, |
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is_constructible<_Tp, _Args..., const _Alloc&>>::value, |
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"construction with an allocator must be possible" |
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" if uses_allocator is true"); |
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}; |
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|
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template<typename _Tp, typename _Alloc, typename... _Args> |
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struct __uses_alloc<false, _Tp, _Alloc, _Args...> |
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: __uses_alloc0 { }; |
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|
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template<typename _Tp, typename _Alloc, typename... _Args> |
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using __uses_alloc_t = |
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__uses_alloc<uses_allocator<_Tp, _Alloc>::value, _Tp, _Alloc, _Args...>; |
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|
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template<typename _Tp, typename _Alloc, typename... _Args> |
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_GLIBCXX20_CONSTEXPR |
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inline __uses_alloc_t<_Tp, _Alloc, _Args...> |
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__use_alloc(const _Alloc& __a) |
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{ |
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__uses_alloc_t<_Tp, _Alloc, _Args...> __ret; |
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__ret._M_a = std::__addressof(__a); |
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return __ret; |
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} |
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|
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template<typename _Tp, typename _Alloc, typename... _Args> |
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void |
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__use_alloc(const _Alloc&&) = delete; |
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|
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#if __cplusplus > 201402L |
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template <typename _Tp, typename _Alloc> |
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inline constexpr bool uses_allocator_v = |
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uses_allocator<_Tp, _Alloc>::value; |
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#endif // C++17 |
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|
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template<template<typename...> class _Predicate, |
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typename _Tp, typename _Alloc, typename... _Args> |
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struct __is_uses_allocator_predicate |
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: conditional<uses_allocator<_Tp, _Alloc>::value, |
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__or_<_Predicate<_Tp, allocator_arg_t, _Alloc, _Args...>, |
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_Predicate<_Tp, _Args..., _Alloc>>, |
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_Predicate<_Tp, _Args...>>::type { }; |
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|
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template<typename _Tp, typename _Alloc, typename... _Args> |
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struct __is_uses_allocator_constructible |
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: __is_uses_allocator_predicate<is_constructible, _Tp, _Alloc, _Args...> |
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{ }; |
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|
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#if __cplusplus >= 201402L |
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template<typename _Tp, typename _Alloc, typename... _Args> |
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_GLIBCXX17_INLINE constexpr bool __is_uses_allocator_constructible_v = |
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__is_uses_allocator_constructible<_Tp, _Alloc, _Args...>::value; |
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#endif // C++14 |
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|
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template<typename _Tp, typename _Alloc, typename... _Args> |
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struct __is_nothrow_uses_allocator_constructible |
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: __is_uses_allocator_predicate<is_nothrow_constructible, |
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_Tp, _Alloc, _Args...> |
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{ }; |
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|
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|
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#if __cplusplus >= 201402L |
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template<typename _Tp, typename _Alloc, typename... _Args> |
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_GLIBCXX17_INLINE constexpr bool |
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__is_nothrow_uses_allocator_constructible_v = |
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__is_nothrow_uses_allocator_constructible<_Tp, _Alloc, _Args...>::value; |
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#endif // C++14 |
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|
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template<typename _Tp, typename... _Args> |
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void __uses_allocator_construct_impl(__uses_alloc0 __a, _Tp* __ptr, |
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_Args&&... __args) |
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{ ::new ((void*)__ptr) _Tp(std::forward<_Args>(__args)...); } |
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|
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template<typename _Tp, typename _Alloc, typename... _Args> |
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void __uses_allocator_construct_impl(__uses_alloc1<_Alloc> __a, _Tp* __ptr, |
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_Args&&... __args) |
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{ |
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::new ((void*)__ptr) _Tp(allocator_arg, *__a._M_a, |
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std::forward<_Args>(__args)...); |
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} |
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|
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template<typename _Tp, typename _Alloc, typename... _Args> |
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void __uses_allocator_construct_impl(__uses_alloc2<_Alloc> __a, _Tp* __ptr, |
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_Args&&... __args) |
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{ ::new ((void*)__ptr) _Tp(std::forward<_Args>(__args)..., *__a._M_a); } |
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|
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template<typename _Tp, typename _Alloc, typename... _Args> |
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void __uses_allocator_construct(const _Alloc& __a, _Tp* __ptr, |
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_Args&&... __args) |
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{ |
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std::__uses_allocator_construct_impl( |
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std::__use_alloc<_Tp, _Alloc, _Args...>(__a), __ptr, |
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std::forward<_Args>(__args)...); |
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} |
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|
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_GLIBCXX_END_NAMESPACE_VERSION |
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} // namespace std |
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|
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#endif |
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#endif |
