mirror of git://gcc.gnu.org/git/gcc.git
1054 lines
34 KiB
C++
1054 lines
34 KiB
C++
// Allocator traits -*- C++ -*-
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// Copyright (C) 2011-2025 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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// 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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// 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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// 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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/** @file bits/alloc_traits.h
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* This is an internal header file, included by other library headers.
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* Do not attempt to use it directly. @headername{memory}
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*/
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#ifndef _ALLOC_TRAITS_H
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#define _ALLOC_TRAITS_H 1
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#include <bits/stl_construct.h>
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#include <bits/memoryfwd.h>
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#if __cplusplus >= 201103L
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# include <bits/ptr_traits.h>
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# include <ext/numeric_traits.h>
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# if _GLIBCXX_HOSTED
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# include <bits/allocator.h>
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# endif
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# if __cpp_exceptions
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# include <bits/stl_iterator.h> // __make_move_if_noexcept_iterator
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# endif
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#endif
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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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#if __cplusplus >= 201103L
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#pragma GCC diagnostic push
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#pragma GCC diagnostic ignored "-Wc++14-extensions" // for variable templates
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#pragma GCC diagnostic ignored "-Wc++17-extensions" // for if-constexpr
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/// @cond undocumented
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struct __allocator_traits_base
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{
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#if __cpp_concepts
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template<typename _Tp, typename _Up>
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#else
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template<typename _Tp, typename _Up, typename = void>
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#endif
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struct __rebind : __replace_first_arg<_Tp, _Up>
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{
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static_assert(is_same<
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typename __replace_first_arg<_Tp, typename _Tp::value_type>::type,
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_Tp>::value,
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"allocator_traits<A>::rebind_alloc<A::value_type> must be A");
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};
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template<typename _Tp, typename _Up>
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#if __cpp_concepts
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requires requires { typename _Tp::template rebind<_Up>::other; }
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struct __rebind<_Tp, _Up>
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#else
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struct __rebind<_Tp, _Up,
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__void_t<typename _Tp::template rebind<_Up>::other>>
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#endif
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{
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using type = typename _Tp::template rebind<_Up>::other;
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static_assert(is_same<
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typename _Tp::template rebind<typename _Tp::value_type>::other,
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_Tp>::value,
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"allocator_traits<A>::rebind_alloc<A::value_type> must be A");
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};
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protected:
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template<typename _Tp>
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using __pointer = typename _Tp::pointer;
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template<typename _Tp>
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using __c_pointer = typename _Tp::const_pointer;
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template<typename _Tp>
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using __v_pointer = typename _Tp::void_pointer;
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template<typename _Tp>
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using __cv_pointer = typename _Tp::const_void_pointer;
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template<typename _Tp>
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using __pocca = typename _Tp::propagate_on_container_copy_assignment;
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template<typename _Tp>
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using __pocma = typename _Tp::propagate_on_container_move_assignment;
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template<typename _Tp>
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using __pocs = typename _Tp::propagate_on_container_swap;
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template<typename _Tp>
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using __equal = __type_identity<typename _Tp::is_always_equal>;
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// __has_allocate_hint is true if a.allocate(n, hint) is well-formed.
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#if __cpp_concepts
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template<typename _Alloc, typename _Sz, typename _Vp>
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static constexpr bool __has_allocate_hint
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= requires (_Alloc& __a, _Sz __n, _Vp __hint) {
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__a.allocate(__n, __hint);
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};
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#else
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template<typename _Alloc, typename _Sz, typename _Vp>
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using __allocate_hint_t
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= decltype(std::declval<_Alloc&>()
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.allocate(std::declval<_Sz>(), std::declval<_Vp>()));
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template<typename _Alloc, typename _Sz, typename _Vp, typename = void>
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static constexpr bool __has_allocate_hint = false;
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template<typename _Alloc, typename _Sz, typename _Vp>
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static constexpr bool
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__has_allocate_hint<_Alloc, _Sz, _Vp,
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__void_t<__allocate_hint_t<_Alloc, _Sz, _Vp>>>
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= true;
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#endif
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// __has_construct is true if a.construct(p, args...) is well-formed.
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// __can_construct is true if either __has_construct is true, or if
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// a placement new-expression for T(args...) is well-formed. We use this
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// to constrain allocator_traits::construct, as a libstdc++ extension.
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#if __cpp_concepts
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template<typename _Alloc, typename _Tp, typename... _Args>
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static constexpr bool __has_construct
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= requires (_Alloc& __a, _Tp* __p, _Args&&... __args) {
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__a.construct(__p, std::forward<_Args>(__args)...);
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};
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template<typename _Tp, typename... _Args>
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static constexpr bool __can_construct_at
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= requires (_Tp* __p, _Args&&... __args) {
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#if __cpp_constexpr_dynamic_alloc
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std::construct_at(__p, std::forward<_Args>(__args)...);
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#else
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::new((void*)__p) _Tp(std::forward<_Args>(__args)...);
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#endif
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};
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template<typename _Alloc, typename _Tp, typename... _Args>
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static constexpr bool __can_construct
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= __has_construct<_Alloc, _Tp, _Args...>
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|| __can_construct_at<_Tp, _Args...>;
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#else
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template<typename _Alloc, typename _Tp, typename... _Args>
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using __construct_t
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= decltype(std::declval<_Alloc&>().construct(std::declval<_Tp*>(),
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std::declval<_Args>()...));
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template<typename _Alloc, typename _Tp, typename, typename... _Args>
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static constexpr bool __has_construct_impl = false;
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template<typename _Alloc, typename _Tp, typename... _Args>
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static constexpr bool
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__has_construct_impl<_Alloc, _Tp,
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__void_t<__construct_t<_Alloc, _Tp, _Args...>>,
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_Args...>
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= true;
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template<typename _Alloc, typename _Tp, typename... _Args>
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static constexpr bool __has_construct
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= __has_construct_impl<_Alloc, _Tp, void, _Args...>;
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template<typename _Tp, typename... _Args>
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using __new_expr_t
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= decltype(::new((void*)0) _Tp(std::declval<_Args>()...));
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template<typename _Tp, typename, typename... _Args>
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static constexpr bool __has_new_expr = false;
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template<typename _Tp, typename... _Args>
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static constexpr bool
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__has_new_expr<_Tp, __void_t<__new_expr_t<_Tp, _Args...>>, _Args...>
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= true;
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template<typename _Alloc, typename _Tp, typename... _Args>
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static constexpr bool __can_construct
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= __has_construct<_Alloc, _Tp, _Args...>
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|| __has_new_expr<_Tp, void, _Args...>;
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#endif
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// __has_destroy is true if a.destroy(p) is well-formed.
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#if __cpp_concepts
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template<typename _Alloc, typename _Tp>
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static constexpr bool __has_destroy = requires (_Alloc& __a, _Tp* __p) {
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__a.destroy(__p);
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};
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#else
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template<typename _Alloc, typename _Tp>
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using __destroy_t
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= decltype(std::declval<_Alloc&>().destroy(std::declval<_Tp*>()));
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template<typename _Alloc, typename _Tp, typename = void>
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static constexpr bool __has_destroy = false;
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template<typename _Alloc, typename _Tp>
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static constexpr bool __has_destroy<_Alloc, _Tp,
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__void_t<__destroy_t<_Alloc, _Tp>>>
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= true;
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#endif
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// __has_max_size is true if a.max_size() is well-formed.
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#if __cpp_concepts
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template<typename _Alloc>
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static constexpr bool __has_max_size = requires (const _Alloc& __a) {
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__a.max_size();
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};
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#else
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template<typename _Alloc>
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using __max_size_t = decltype(std::declval<const _Alloc&>().max_size());
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template<typename _Alloc, typename = void>
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static constexpr bool __has_max_size = false;
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template<typename _Alloc>
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static constexpr bool __has_max_size<_Alloc,
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__void_t<__max_size_t<_Alloc>>>
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= true;
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#endif
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// __has_soccc is true if a.select_on_container_copy_construction()
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// is well-formed.
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#if __cpp_concepts
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template<typename _Alloc>
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static constexpr bool __has_soccc = requires (const _Alloc& __a) {
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__a.select_on_container_copy_construction();
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};
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#else
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template<typename _Alloc>
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using __soccc_t
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= decltype(std::declval<const _Alloc&>()
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.select_on_container_copy_construction());
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template<typename _Alloc, typename = void>
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static constexpr bool __has_soccc = false;
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template<typename _Alloc>
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static constexpr bool __has_soccc<_Alloc, __void_t<__soccc_t<_Alloc>>>
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= true;
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#endif
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};
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template<typename _Alloc, typename _Up>
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using __alloc_rebind
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= typename __allocator_traits_base::template __rebind<_Alloc, _Up>::type;
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/// @endcond
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/**
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* @brief Uniform interface to all allocator types.
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* @headerfile memory
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* @ingroup allocators
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* @since C++11
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*/
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template<typename _Alloc>
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struct allocator_traits : __allocator_traits_base
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{
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/// The allocator type
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typedef _Alloc allocator_type;
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/// The allocated type
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typedef typename _Alloc::value_type value_type;
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/**
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* @brief The allocator's pointer type.
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*
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* @c Alloc::pointer if that type exists, otherwise @c value_type*
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*/
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using pointer = __detected_or_t<value_type*, __pointer, _Alloc>;
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private:
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// Select _Func<_Alloc> or pointer_traits<pointer>::rebind<_Tp>
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template<template<typename> class _Func, typename _Tp, typename = void>
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struct _Ptr
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{
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using type = typename pointer_traits<pointer>::template rebind<_Tp>;
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};
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template<template<typename> class _Func, typename _Tp>
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struct _Ptr<_Func, _Tp, __void_t<_Func<_Alloc>>>
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{
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using type = _Func<_Alloc>;
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};
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// Select _A2::difference_type or pointer_traits<_Ptr>::difference_type
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template<typename _A2, typename _PtrT, typename = void>
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struct _Diff
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{ using type = typename pointer_traits<_PtrT>::difference_type; };
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template<typename _A2, typename _PtrT>
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struct _Diff<_A2, _PtrT, __void_t<typename _A2::difference_type>>
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{ using type = typename _A2::difference_type; };
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// Select _A2::size_type or make_unsigned<_DiffT>::type
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template<typename _A2, typename _DiffT, typename = void>
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struct _Size : make_unsigned<_DiffT> { };
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template<typename _A2, typename _DiffT>
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struct _Size<_A2, _DiffT, __void_t<typename _A2::size_type>>
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{ using type = typename _A2::size_type; };
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public:
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/**
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* @brief The allocator's const pointer type.
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*
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* @c Alloc::const_pointer if that type exists, otherwise
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* <tt> pointer_traits<pointer>::rebind<const value_type> </tt>
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*/
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using const_pointer = typename _Ptr<__c_pointer, const value_type>::type;
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/**
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* @brief The allocator's void pointer type.
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*
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* @c Alloc::void_pointer if that type exists, otherwise
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* <tt> pointer_traits<pointer>::rebind<void> </tt>
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*/
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using void_pointer = typename _Ptr<__v_pointer, void>::type;
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/**
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* @brief The allocator's const void pointer type.
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*
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* @c Alloc::const_void_pointer if that type exists, otherwise
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* <tt> pointer_traits<pointer>::rebind<const void> </tt>
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*/
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using const_void_pointer = typename _Ptr<__cv_pointer, const void>::type;
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/**
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* @brief The allocator's difference type
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*
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* @c Alloc::difference_type if that type exists, otherwise
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* <tt> pointer_traits<pointer>::difference_type </tt>
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*/
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using difference_type = typename _Diff<_Alloc, pointer>::type;
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/**
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* @brief The allocator's size type
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*
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* @c Alloc::size_type if that type exists, otherwise
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* <tt> make_unsigned<difference_type>::type </tt>
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*/
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using size_type = typename _Size<_Alloc, difference_type>::type;
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/**
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* @brief How the allocator is propagated on copy assignment
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*
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* @c Alloc::propagate_on_container_copy_assignment if that type exists,
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* otherwise @c false_type
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*/
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using propagate_on_container_copy_assignment
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= __detected_or_t<false_type, __pocca, _Alloc>;
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/**
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* @brief How the allocator is propagated on move assignment
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*
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* @c Alloc::propagate_on_container_move_assignment if that type exists,
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* otherwise @c false_type
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*/
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using propagate_on_container_move_assignment
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= __detected_or_t<false_type, __pocma, _Alloc>;
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/**
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* @brief How the allocator is propagated on swap
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*
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* @c Alloc::propagate_on_container_swap if that type exists,
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* otherwise @c false_type
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*/
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using propagate_on_container_swap
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= __detected_or_t<false_type, __pocs, _Alloc>;
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/**
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* @brief Whether all instances of the allocator type compare equal.
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*
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* @c Alloc::is_always_equal if that type exists,
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* otherwise @c is_empty<Alloc>::type
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*/
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using is_always_equal
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= typename __detected_or_t<is_empty<_Alloc>, __equal, _Alloc>::type;
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template<typename _Tp>
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using rebind_alloc = __alloc_rebind<_Alloc, _Tp>;
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template<typename _Tp>
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using rebind_traits = allocator_traits<rebind_alloc<_Tp>>;
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/**
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* @brief Allocate memory.
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* @param __a An allocator.
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* @param __n The number of objects to allocate space for.
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*
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* Calls @c a.allocate(n)
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*/
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_GLIBCXX_NODISCARD static _GLIBCXX20_CONSTEXPR pointer
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allocate(_Alloc& __a, size_type __n)
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{ return __a.allocate(__n); }
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/**
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* @brief Allocate memory.
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* @param __a An allocator.
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* @param __n The number of objects to allocate space for.
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* @param __hint Aid to locality.
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* @return Memory of suitable size and alignment for @a n objects
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* of type @c value_type
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*
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* Returns <tt> a.allocate(n, hint) </tt> if that expression is
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* well-formed, otherwise returns @c a.allocate(n)
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*/
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_GLIBCXX_NODISCARD static _GLIBCXX20_CONSTEXPR pointer
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allocate(_Alloc& __a, size_type __n, const_void_pointer __hint)
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{
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if constexpr (__has_allocate_hint<_Alloc, size_type, const_void_pointer>)
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return __a.allocate(__n, __hint);
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else
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return __a.allocate(__n);
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}
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/**
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* @brief Deallocate memory.
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* @param __a An allocator.
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* @param __p Pointer to the memory to deallocate.
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* @param __n The number of objects space was allocated for.
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*
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* Calls <tt> a.deallocate(p, n) </tt>
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*/
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static _GLIBCXX20_CONSTEXPR void
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deallocate(_Alloc& __a, pointer __p, size_type __n)
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{ __a.deallocate(__p, __n); }
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/**
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* @brief Construct an object of type `_Tp`
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* @param __a An allocator.
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* @param __p Pointer to memory of suitable size and alignment for Tp
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* @param __args Constructor arguments.
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*
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* Calls <tt> __a.construct(__p, std::forward<Args>(__args)...) </tt>
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* if that expression is well-formed, otherwise uses placement-new
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* to construct an object of type @a _Tp at location @a __p from the
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* arguments @a __args...
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*/
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template<typename _Tp, typename... _Args>
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#if __cpp_concepts && __cpp_constexpr_dynamic_alloc
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requires __can_construct<_Alloc, _Tp, _Args...>
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static constexpr void
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#else
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static __enable_if_t<__can_construct<_Alloc, _Tp, _Args...>>
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#endif
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construct(_Alloc& __a, _Tp* __p, _Args&&... __args)
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noexcept(_S_nothrow_construct<_Tp, _Args...>())
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{
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if constexpr (__has_construct<_Alloc, _Tp, _Args...>)
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__a.construct(__p, std::forward<_Args>(__args)...);
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else
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std::_Construct(__p, std::forward<_Args>(__args)...);
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}
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/**
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* @brief Destroy an object of type @a _Tp
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* @param __a An allocator.
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* @param __p Pointer to the object to destroy
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*
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* Calls @c __a.destroy(__p) if that expression is well-formed,
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* otherwise calls @c __p->~_Tp()
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*/
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template<typename _Tp>
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static _GLIBCXX20_CONSTEXPR void
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destroy(_Alloc& __a, _Tp* __p)
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noexcept(_S_nothrow_destroy<_Tp>())
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{
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if constexpr (__has_destroy<_Alloc, _Tp>)
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__a.destroy(__p);
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else
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std::_Destroy(__p);
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}
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/**
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* @brief The maximum supported allocation size
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* @param __a An allocator.
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* @return @c __a.max_size() or @c numeric_limits<size_type>::max()
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*
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* Returns @c __a.max_size() if that expression is well-formed,
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* otherwise returns @c numeric_limits<size_type>::max()
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*/
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static _GLIBCXX20_CONSTEXPR size_type
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max_size(const _Alloc& __a) noexcept
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{
|
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if constexpr (__has_max_size<_Alloc>)
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return __a.max_size();
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else
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// _GLIBCXX_RESOLVE_LIB_DEFECTS
|
|
// 2466. allocator_traits::max_size() default behavior is incorrect
|
|
return __gnu_cxx::__numeric_traits<size_type>::__max
|
|
/ sizeof(value_type);
|
|
}
|
|
|
|
/**
|
|
* @brief Obtain an allocator to use when copying a container.
|
|
* @param __rhs An allocator.
|
|
* @return @c __rhs.select_on_container_copy_construction() or @a __rhs
|
|
*
|
|
* Returns @c __rhs.select_on_container_copy_construction() if that
|
|
* expression is well-formed, otherwise returns @a __rhs
|
|
*/
|
|
static _GLIBCXX20_CONSTEXPR _Alloc
|
|
select_on_container_copy_construction(const _Alloc& __rhs)
|
|
{
|
|
if constexpr (__has_soccc<_Alloc>)
|
|
return __rhs.select_on_container_copy_construction();
|
|
else
|
|
return __rhs;
|
|
}
|
|
|
|
private:
|
|
#if __cpp_constexpr >= 201304 // >= C++14
|
|
template<typename _Tp, typename... _Args>
|
|
static constexpr bool
|
|
_S_nothrow_construct(_Alloc* __a = nullptr, _Tp* __p = nullptr)
|
|
{
|
|
if constexpr (__has_construct<_Alloc, _Tp, _Args...>)
|
|
return noexcept(__a->construct(__p, std::declval<_Args>()...));
|
|
else
|
|
return __is_nothrow_new_constructible<_Tp, _Args...>;
|
|
}
|
|
|
|
template<typename _Tp>
|
|
static constexpr bool
|
|
_S_nothrow_destroy(_Alloc* __a = nullptr, _Tp* __p = nullptr)
|
|
{
|
|
if constexpr (__has_destroy<_Alloc, _Tp>)
|
|
return noexcept(__a->destroy(__p));
|
|
else
|
|
return is_nothrow_destructible<_Tp>::value;
|
|
}
|
|
#else
|
|
template<typename _Tp, typename... _Args>
|
|
static constexpr
|
|
__enable_if_t<__has_construct<_Alloc, _Tp, _Args...>, bool>
|
|
_S_nothrow_construct(_Alloc* __a = nullptr, _Tp* __p = nullptr)
|
|
{ return noexcept(__a->construct(__p, std::declval<_Args>()...)); }
|
|
|
|
template<typename _Tp, typename... _Args>
|
|
static constexpr
|
|
__enable_if_t<!__has_construct<_Alloc, _Tp, _Args...>, bool>
|
|
_S_nothrow_construct(_Alloc* = nullptr, _Tp* __p = nullptr)
|
|
{ return __is_nothrow_new_constructible<_Tp, _Args...>; }
|
|
|
|
template<typename _Tp>
|
|
static constexpr
|
|
__enable_if_t<__has_destroy<_Alloc, _Tp>, bool>
|
|
_S_nothrow_destroy(_Alloc* __a = nullptr, _Tp* __p = nullptr)
|
|
{ return noexcept(__a->destroy(__p)); }
|
|
|
|
template<typename _Tp>
|
|
static constexpr
|
|
__enable_if_t<!__has_destroy<_Alloc, _Tp>, bool>
|
|
_S_nothrow_destroy(_Alloc* = nullptr, _Tp* __p = nullptr)
|
|
{ return is_nothrow_destructible<_Tp>::value; }
|
|
#endif
|
|
};
|
|
#pragma GCC diagnostic pop
|
|
|
|
#if _GLIBCXX_HOSTED
|
|
/**
|
|
* @brief Partial specialization for `std::allocator`
|
|
* @headerfile memory
|
|
* @ingroup allocators
|
|
* @since C++11
|
|
* @see std::allocator_traits
|
|
*/
|
|
template<typename _Tp>
|
|
struct allocator_traits<allocator<_Tp>>
|
|
{
|
|
/// The allocator type
|
|
using allocator_type = allocator<_Tp>;
|
|
|
|
/// The allocated type
|
|
using value_type = _Tp;
|
|
|
|
/// The allocator's pointer type.
|
|
using pointer = _Tp*;
|
|
|
|
/// The allocator's const pointer type.
|
|
using const_pointer = const _Tp*;
|
|
|
|
/// The allocator's void pointer type.
|
|
using void_pointer = void*;
|
|
|
|
/// The allocator's const void pointer type.
|
|
using const_void_pointer = const void*;
|
|
|
|
/// The allocator's difference type
|
|
using difference_type = std::ptrdiff_t;
|
|
|
|
/// The allocator's size type
|
|
using size_type = std::size_t;
|
|
|
|
/// How the allocator is propagated on copy assignment
|
|
using propagate_on_container_copy_assignment = false_type;
|
|
|
|
/// How the allocator is propagated on move assignment
|
|
using propagate_on_container_move_assignment = true_type;
|
|
|
|
/// How the allocator is propagated on swap
|
|
using propagate_on_container_swap = false_type;
|
|
|
|
/// Whether all instances of the allocator type compare equal.
|
|
using is_always_equal = true_type;
|
|
|
|
template<typename _Up>
|
|
using rebind_alloc = allocator<_Up>;
|
|
|
|
template<typename _Up>
|
|
using rebind_traits = allocator_traits<allocator<_Up>>;
|
|
|
|
/**
|
|
* @brief Allocate memory.
|
|
* @param __a An allocator.
|
|
* @param __n The number of objects to allocate space for.
|
|
*
|
|
* Calls @c a.allocate(n)
|
|
*/
|
|
[[__nodiscard__,__gnu__::__always_inline__]]
|
|
static _GLIBCXX20_CONSTEXPR pointer
|
|
allocate(allocator_type& __a, size_type __n)
|
|
{ return __a.allocate(__n); }
|
|
|
|
/**
|
|
* @brief Allocate memory.
|
|
* @param __a An allocator.
|
|
* @param __n The number of objects to allocate space for.
|
|
* @param __hint Aid to locality.
|
|
* @return Memory of suitable size and alignment for @a n objects
|
|
* of type @c value_type
|
|
*
|
|
* Returns <tt> a.allocate(n, hint) </tt>
|
|
*/
|
|
[[__nodiscard__,__gnu__::__always_inline__]]
|
|
static _GLIBCXX20_CONSTEXPR pointer
|
|
allocate(allocator_type& __a, size_type __n,
|
|
[[maybe_unused]] const_void_pointer __hint)
|
|
{
|
|
#if __cplusplus <= 201703L
|
|
return __a.allocate(__n, __hint);
|
|
#else
|
|
return __a.allocate(__n);
|
|
#endif
|
|
}
|
|
|
|
/**
|
|
* @brief Deallocate memory.
|
|
* @param __a An allocator.
|
|
* @param __p Pointer to the memory to deallocate.
|
|
* @param __n The number of objects space was allocated for.
|
|
*
|
|
* Calls <tt> a.deallocate(p, n) </tt>
|
|
*/
|
|
[[__gnu__::__always_inline__]]
|
|
static _GLIBCXX20_CONSTEXPR void
|
|
deallocate(allocator_type& __a, pointer __p, size_type __n)
|
|
{ __a.deallocate(__p, __n); }
|
|
|
|
/**
|
|
* @brief Construct an object of type `_Up`
|
|
* @param __a An allocator.
|
|
* @param __p Pointer to memory of suitable size and alignment for
|
|
* an object of type `_Up`.
|
|
* @param __args Constructor arguments.
|
|
*
|
|
* Calls `__a.construct(__p, std::forward<_Args>(__args)...)`
|
|
* in C++11, C++14 and C++17. Changed in C++20 to call
|
|
* `std::construct_at(__p, std::forward<_Args>(__args)...)` instead.
|
|
*/
|
|
template<typename _Up, typename... _Args>
|
|
[[__gnu__::__always_inline__]]
|
|
static _GLIBCXX20_CONSTEXPR void
|
|
construct(allocator_type& __a __attribute__((__unused__)),
|
|
_Up* __p, _Args&&... __args)
|
|
#if __cplusplus <= 201703L
|
|
noexcept(noexcept(__a.construct(__p, std::forward<_Args>(__args)...)))
|
|
#else
|
|
noexcept(__is_nothrow_new_constructible<_Up, _Args...>)
|
|
#endif
|
|
{
|
|
#if __cplusplus <= 201703L
|
|
__a.construct(__p, std::forward<_Args>(__args)...);
|
|
#elif __cpp_constexpr_dynamic_alloc // >= C++20
|
|
std::construct_at(__p, std::forward<_Args>(__args)...);
|
|
#else
|
|
std::_Construct(__p, std::forward<_Args>(__args)...);
|
|
#endif
|
|
}
|
|
|
|
/**
|
|
* @brief Destroy an object of type @a _Up
|
|
* @param __a An allocator.
|
|
* @param __p Pointer to the object to destroy
|
|
*
|
|
* Calls @c __a.destroy(__p).
|
|
*/
|
|
template<typename _Up>
|
|
[[__gnu__::__always_inline__]]
|
|
static _GLIBCXX20_CONSTEXPR void
|
|
destroy(allocator_type& __a __attribute__((__unused__)), _Up* __p)
|
|
noexcept(is_nothrow_destructible<_Up>::value)
|
|
{
|
|
#if __cplusplus <= 201703L
|
|
__a.destroy(__p);
|
|
#else
|
|
std::destroy_at(__p);
|
|
#endif
|
|
}
|
|
|
|
/**
|
|
* @brief The maximum supported allocation size
|
|
* @param __a An allocator.
|
|
* @return @c __a.max_size()
|
|
*/
|
|
[[__gnu__::__always_inline__]]
|
|
static _GLIBCXX20_CONSTEXPR size_type
|
|
max_size(const allocator_type& __a __attribute__((__unused__))) noexcept
|
|
{
|
|
#if __cplusplus <= 201703L
|
|
return __a.max_size();
|
|
#else
|
|
return size_t(-1) / sizeof(value_type);
|
|
#endif
|
|
}
|
|
|
|
/**
|
|
* @brief Obtain an allocator to use when copying a container.
|
|
* @param __rhs An allocator.
|
|
* @return @c __rhs
|
|
*/
|
|
[[__gnu__::__always_inline__]]
|
|
static _GLIBCXX20_CONSTEXPR allocator_type
|
|
select_on_container_copy_construction(const allocator_type& __rhs)
|
|
{ return __rhs; }
|
|
};
|
|
|
|
/**
|
|
* @brief Explicit specialization for `std::allocator<void>`
|
|
* @headerfile memory
|
|
* @ingroup allocators
|
|
* @since C++11
|
|
* @see std::allocator_traits
|
|
*/
|
|
template<>
|
|
struct allocator_traits<allocator<void>>
|
|
{
|
|
/// The allocator type
|
|
using allocator_type = allocator<void>;
|
|
|
|
/// The allocated type
|
|
using value_type = void;
|
|
|
|
/// The allocator's pointer type.
|
|
using pointer = void*;
|
|
|
|
/// The allocator's const pointer type.
|
|
using const_pointer = const void*;
|
|
|
|
/// The allocator's void pointer type.
|
|
using void_pointer = void*;
|
|
|
|
/// The allocator's const void pointer type.
|
|
using const_void_pointer = const void*;
|
|
|
|
/// The allocator's difference type
|
|
using difference_type = std::ptrdiff_t;
|
|
|
|
/// The allocator's size type
|
|
using size_type = std::size_t;
|
|
|
|
/// How the allocator is propagated on copy assignment
|
|
using propagate_on_container_copy_assignment = false_type;
|
|
|
|
/// How the allocator is propagated on move assignment
|
|
using propagate_on_container_move_assignment = true_type;
|
|
|
|
/// How the allocator is propagated on swap
|
|
using propagate_on_container_swap = false_type;
|
|
|
|
/// Whether all instances of the allocator type compare equal.
|
|
using is_always_equal = true_type;
|
|
|
|
template<typename _Up>
|
|
using rebind_alloc = allocator<_Up>;
|
|
|
|
template<typename _Up>
|
|
using rebind_traits = allocator_traits<allocator<_Up>>;
|
|
|
|
/// allocate is ill-formed for allocator<void>
|
|
static void*
|
|
allocate(allocator_type&, size_type, const void* = nullptr) = delete;
|
|
|
|
/// deallocate is ill-formed for allocator<void>
|
|
static void
|
|
deallocate(allocator_type&, void*, size_type) = delete;
|
|
|
|
/**
|
|
* @brief Construct an object of type `_Up`
|
|
* @param __a An allocator.
|
|
* @param __p Pointer to memory of suitable size and alignment for
|
|
* an object of type `_Up`.
|
|
* @param __args Constructor arguments.
|
|
*
|
|
* Calls `__a.construct(__p, std::forward<_Args>(__args)...)`
|
|
* in C++11, C++14 and C++17. Changed in C++20 to call
|
|
* `std::construct_at(__p, std::forward<_Args>(__args)...)` instead.
|
|
*/
|
|
template<typename _Up, typename... _Args>
|
|
[[__gnu__::__always_inline__]]
|
|
static _GLIBCXX20_CONSTEXPR void
|
|
construct(allocator_type&, _Up* __p, _Args&&... __args)
|
|
noexcept(__is_nothrow_new_constructible<_Up, _Args...>)
|
|
{ std::_Construct(__p, std::forward<_Args>(__args)...); }
|
|
|
|
/**
|
|
* @brief Destroy an object of type `_Up`
|
|
* @param __a An allocator.
|
|
* @param __p Pointer to the object to destroy
|
|
*
|
|
* Invokes the destructor for `*__p`.
|
|
*/
|
|
template<typename _Up>
|
|
[[__gnu__::__always_inline__]]
|
|
static _GLIBCXX20_CONSTEXPR void
|
|
destroy(allocator_type&, _Up* __p)
|
|
noexcept(is_nothrow_destructible<_Up>::value)
|
|
{ std::_Destroy(__p); }
|
|
|
|
/// max_size is ill-formed for allocator<void>
|
|
static size_type
|
|
max_size(const allocator_type&) = delete;
|
|
|
|
/**
|
|
* @brief Obtain an allocator to use when copying a container.
|
|
* @param __rhs An allocator.
|
|
* @return `__rhs`
|
|
*/
|
|
[[__gnu__::__always_inline__]]
|
|
static _GLIBCXX20_CONSTEXPR allocator_type
|
|
select_on_container_copy_construction(const allocator_type& __rhs)
|
|
{ return __rhs; }
|
|
};
|
|
#endif
|
|
|
|
/// @cond undocumented
|
|
#pragma GCC diagnostic push
|
|
#pragma GCC diagnostic ignored "-Wc++17-extensions" // if constexpr
|
|
template<typename _Alloc>
|
|
[[__gnu__::__always_inline__]]
|
|
_GLIBCXX14_CONSTEXPR inline void
|
|
__alloc_on_copy(_Alloc& __one, const _Alloc& __two)
|
|
{
|
|
using __traits = allocator_traits<_Alloc>;
|
|
using __pocca =
|
|
typename __traits::propagate_on_container_copy_assignment::type;
|
|
if constexpr (__pocca::value)
|
|
__one = __two;
|
|
}
|
|
|
|
template<typename _Alloc>
|
|
[[__gnu__::__always_inline__]]
|
|
constexpr _Alloc
|
|
__alloc_on_copy(const _Alloc& __a)
|
|
{
|
|
typedef allocator_traits<_Alloc> __traits;
|
|
return __traits::select_on_container_copy_construction(__a);
|
|
}
|
|
|
|
template<typename _Alloc>
|
|
[[__gnu__::__always_inline__]]
|
|
_GLIBCXX14_CONSTEXPR inline void
|
|
__alloc_on_move(_Alloc& __one, _Alloc& __two)
|
|
{
|
|
using __traits = allocator_traits<_Alloc>;
|
|
using __pocma
|
|
= typename __traits::propagate_on_container_move_assignment::type;
|
|
if constexpr (__pocma::value)
|
|
__one = std::move(__two);
|
|
}
|
|
|
|
template<typename _Alloc>
|
|
[[__gnu__::__always_inline__]]
|
|
_GLIBCXX14_CONSTEXPR inline void
|
|
__alloc_on_swap(_Alloc& __one, _Alloc& __two)
|
|
{
|
|
using __traits = allocator_traits<_Alloc>;
|
|
using __pocs = typename __traits::propagate_on_container_swap::type;
|
|
if constexpr (__pocs::value)
|
|
{
|
|
using std::swap;
|
|
swap(__one, __two);
|
|
}
|
|
}
|
|
#pragma GCC diagnostic pop
|
|
|
|
template<typename _Alloc, typename _Tp,
|
|
typename _ValueT = __remove_cvref_t<typename _Alloc::value_type>,
|
|
typename = void>
|
|
struct __is_alloc_insertable_impl
|
|
: false_type
|
|
{ };
|
|
|
|
template<typename _Alloc, typename _Tp, typename _ValueT>
|
|
struct __is_alloc_insertable_impl<_Alloc, _Tp, _ValueT,
|
|
__void_t<decltype(allocator_traits<_Alloc>::construct(
|
|
std::declval<_Alloc&>(), std::declval<_ValueT*>(),
|
|
std::declval<_Tp>()))>>
|
|
: true_type
|
|
{ };
|
|
|
|
// true if _Alloc::value_type is CopyInsertable into containers using _Alloc
|
|
// (might be wrong if _Alloc::construct exists but is not constrained,
|
|
// i.e. actually trying to use it would still be invalid. Use with caution.)
|
|
template<typename _Alloc>
|
|
struct __is_copy_insertable
|
|
: __is_alloc_insertable_impl<_Alloc,
|
|
typename _Alloc::value_type const&>::type
|
|
{ };
|
|
|
|
#if _GLIBCXX_HOSTED
|
|
// std::allocator<_Tp> just requires CopyConstructible
|
|
template<typename _Tp>
|
|
struct __is_copy_insertable<allocator<_Tp>>
|
|
: is_copy_constructible<_Tp>
|
|
{ };
|
|
#endif
|
|
|
|
// true if _Alloc::value_type is MoveInsertable into containers using _Alloc
|
|
// (might be wrong if _Alloc::construct exists but is not constrained,
|
|
// i.e. actually trying to use it would still be invalid. Use with caution.)
|
|
template<typename _Alloc>
|
|
struct __is_move_insertable
|
|
: __is_alloc_insertable_impl<_Alloc, typename _Alloc::value_type>::type
|
|
{ };
|
|
|
|
#if _GLIBCXX_HOSTED
|
|
// std::allocator<_Tp> just requires MoveConstructible
|
|
template<typename _Tp>
|
|
struct __is_move_insertable<allocator<_Tp>>
|
|
: is_move_constructible<_Tp>
|
|
{ };
|
|
#endif
|
|
|
|
// Trait to detect Allocator-like types.
|
|
template<typename _Alloc, typename = void>
|
|
struct __is_allocator : false_type { };
|
|
|
|
template<typename _Alloc>
|
|
struct __is_allocator<_Alloc,
|
|
__void_t<typename _Alloc::value_type,
|
|
decltype(std::declval<_Alloc&>().allocate(size_t{}))>>
|
|
: true_type { };
|
|
|
|
template<typename _Alloc>
|
|
using _RequireAllocator
|
|
= typename enable_if<__is_allocator<_Alloc>::value, _Alloc>::type;
|
|
|
|
template<typename _Alloc>
|
|
using _RequireNotAllocator
|
|
= typename enable_if<!__is_allocator<_Alloc>::value, _Alloc>::type;
|
|
|
|
#if __cpp_concepts >= 201907L
|
|
template<typename _Alloc>
|
|
concept __allocator_like = requires (_Alloc& __a) {
|
|
typename _Alloc::value_type;
|
|
__a.deallocate(__a.allocate(1u), 1u);
|
|
};
|
|
|
|
template<typename _Alloc>
|
|
concept __not_allocator_like = !__allocator_like<_Alloc>;
|
|
#endif
|
|
/// @endcond
|
|
#endif // C++11
|
|
|
|
/// @cond undocumented
|
|
|
|
// To implement Option 3 of DR 431.
|
|
template<typename _Alloc, bool = __is_empty(_Alloc)>
|
|
struct __alloc_swap
|
|
{ static void _S_do_it(_Alloc&, _Alloc&) _GLIBCXX_NOEXCEPT { } };
|
|
|
|
template<typename _Alloc>
|
|
struct __alloc_swap<_Alloc, false>
|
|
{
|
|
static void
|
|
_S_do_it(_Alloc& __one, _Alloc& __two) _GLIBCXX_NOEXCEPT
|
|
{
|
|
// Precondition: swappable allocators.
|
|
if (__one != __two)
|
|
swap(__one, __two);
|
|
}
|
|
};
|
|
|
|
#if __cplusplus >= 201103L
|
|
template<typename _Tp, bool
|
|
= __or_<is_copy_constructible<typename _Tp::value_type>,
|
|
is_nothrow_move_constructible<typename _Tp::value_type>>::value>
|
|
struct __shrink_to_fit_aux
|
|
{ static bool _S_do_it(_Tp&) noexcept { return false; } };
|
|
|
|
template<typename _Tp>
|
|
struct __shrink_to_fit_aux<_Tp, true>
|
|
{
|
|
_GLIBCXX20_CONSTEXPR
|
|
static bool
|
|
_S_do_it(_Tp& __c) noexcept
|
|
{
|
|
#if __cpp_exceptions
|
|
try
|
|
{
|
|
_Tp(__make_move_if_noexcept_iterator(__c.begin()),
|
|
__make_move_if_noexcept_iterator(__c.end()),
|
|
__c.get_allocator()).swap(__c);
|
|
return true;
|
|
}
|
|
catch(...)
|
|
{ return false; }
|
|
#else
|
|
return false;
|
|
#endif
|
|
}
|
|
};
|
|
#endif
|
|
|
|
/**
|
|
* Destroy a range of objects using the supplied allocator. For
|
|
* non-default allocators we do not optimize away invocation of
|
|
* destroy() even if _Tp has a trivial destructor.
|
|
*/
|
|
|
|
template<typename _ForwardIterator, typename _Allocator>
|
|
_GLIBCXX20_CONSTEXPR
|
|
void
|
|
_Destroy(_ForwardIterator __first, _ForwardIterator __last,
|
|
_Allocator& __alloc)
|
|
{
|
|
for (; __first != __last; ++__first)
|
|
#if __cplusplus < 201103L
|
|
__alloc.destroy(std::__addressof(*__first));
|
|
#else
|
|
allocator_traits<_Allocator>::destroy(__alloc,
|
|
std::__addressof(*__first));
|
|
#endif
|
|
}
|
|
|
|
#if _GLIBCXX_HOSTED
|
|
template<typename _ForwardIterator, typename _Tp>
|
|
__attribute__((__always_inline__)) _GLIBCXX20_CONSTEXPR
|
|
inline void
|
|
_Destroy(_ForwardIterator __first, _ForwardIterator __last,
|
|
allocator<_Tp>&)
|
|
{
|
|
std::_Destroy(__first, __last);
|
|
}
|
|
#endif
|
|
|
|
/// @endcond
|
|
|
|
_GLIBCXX_END_NAMESPACE_VERSION
|
|
} // namespace std
|
|
#endif // _ALLOC_TRAITS_H
|