mirror of
https://github.com/autc04/Retro68.git
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388 lines
12 KiB
C++
388 lines
12 KiB
C++
// <experimental/memory_resource> -*- C++ -*-
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// Copyright (C) 2015-2016 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 experimental/memory_resource
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* This is a TS C++ Library header.
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*/
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#ifndef _GLIBCXX_EXPERIMENTAL_MEMORY_RESOURCE
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#define _GLIBCXX_EXPERIMENTAL_MEMORY_RESOURCE 1
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#include <memory>
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#include <new>
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#include <atomic>
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#include <cstddef>
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#include <bits/alloc_traits.h>
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#include <experimental/bits/lfts_config.h>
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namespace std {
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namespace experimental {
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inline namespace fundamentals_v2 {
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namespace pmr {
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_GLIBCXX_BEGIN_NAMESPACE_VERSION
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#define __cpp_lib_experimental_memory_resources 201402L
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class memory_resource;
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template <typename _Tp>
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class polymorphic_allocator;
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template <typename _Alloc>
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class __resource_adaptor_imp;
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template <typename _Alloc>
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using resource_adaptor = __resource_adaptor_imp<
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typename allocator_traits<_Alloc>::template rebind_alloc<char>>;
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template <typename _Tp>
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struct __uses_allocator_construction_helper;
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// Global memory resources
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memory_resource* new_delete_resource() noexcept;
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memory_resource* null_memory_resource() noexcept;
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// The default memory resource
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memory_resource* get_default_resource() noexcept;
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memory_resource* set_default_resource(memory_resource* __r) noexcept;
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// Standard memory resources
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// 8.5 Class memory_resource
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class memory_resource
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{
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protected:
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static constexpr size_t _S_max_align = alignof(max_align_t);
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public:
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virtual ~memory_resource() { }
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void*
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allocate(size_t __bytes, size_t __alignment = _S_max_align)
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{ return do_allocate(__bytes, __alignment); }
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void
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deallocate(void* __p, size_t __bytes, size_t __alignment = _S_max_align)
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{ return do_deallocate(__p, __bytes, __alignment); }
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bool
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is_equal(const memory_resource& __other) const noexcept
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{ return do_is_equal(__other); }
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protected:
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virtual void*
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do_allocate(size_t __bytes, size_t __alignment) = 0;
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virtual void
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do_deallocate(void* __p, size_t __bytes, size_t __alignment) = 0;
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virtual bool
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do_is_equal(const memory_resource& __other) const noexcept = 0;
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};
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inline bool
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operator==(const memory_resource& __a,
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const memory_resource& __b) noexcept
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{ return &__a == &__b || __a.is_equal(__b); }
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inline bool
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operator!=(const memory_resource& __a,
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const memory_resource& __b) noexcept
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{ return !(__a == __b); }
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// 8.6 Class template polymorphic_allocator
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template <class _Tp>
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class polymorphic_allocator
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{
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using __uses_alloc1_ = __uses_alloc1<memory_resource*>;
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using __uses_alloc2_ = __uses_alloc2<memory_resource*>;
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template<typename _Tp1, typename... _Args>
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void
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_M_construct(__uses_alloc0, _Tp1* __p, _Args&&... __args)
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{ ::new(__p) _Tp1(std::forward<_Args>(__args)...); }
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template<typename _Tp1, typename... _Args>
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void
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_M_construct(__uses_alloc1_, _Tp1* __p, _Args&&... __args)
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{ ::new(__p) _Tp1(allocator_arg, this->resource(),
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std::forward<_Args>(__args)...); }
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template<typename _Tp1, typename... _Args>
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void
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_M_construct(__uses_alloc2_, _Tp1* __p, _Args&&... __args)
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{ ::new(__p) _Tp1(std::forward<_Args>(__args)...,
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this->resource()); }
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public:
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using value_type = _Tp;
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polymorphic_allocator() noexcept
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: _M_resource(get_default_resource())
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{ }
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polymorphic_allocator(memory_resource* __r)
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: _M_resource(__r)
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{ _GLIBCXX_DEBUG_ASSERT(__r); }
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polymorphic_allocator(const polymorphic_allocator& __other) = default;
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template <typename _Up>
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polymorphic_allocator(const polymorphic_allocator<_Up>&
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__other) noexcept
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: _M_resource(__other.resource())
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{ }
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polymorphic_allocator&
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operator=(const polymorphic_allocator& __rhs) = default;
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_Tp* allocate(size_t __n)
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{ return static_cast<_Tp*>(_M_resource->allocate(__n * sizeof(_Tp),
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alignof(_Tp))); }
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void deallocate(_Tp* __p, size_t __n)
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{ _M_resource->deallocate(__p, __n * sizeof(_Tp), alignof(_Tp)); }
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template <typename _Tp1, typename... _Args> //used here
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void construct(_Tp1* __p, _Args&&... __args)
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{
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auto __use_tag = __use_alloc<_Tp1, memory_resource*,
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_Args...>(this->resource());
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_M_construct(__use_tag, __p, std::forward<_Args>(__args)...);
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}
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// Specializations for pair using piecewise construction
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template <typename _Tp1, typename _Tp2,
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typename... _Args1, typename... _Args2>
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void construct(pair<_Tp1, _Tp2>* __p, piecewise_construct_t,
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tuple<_Args1...> __x,
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tuple<_Args2...> __y)
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{
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auto __x_use_tag =
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__use_alloc<_Tp1, memory_resource*, _Args1...>(this->resource());
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auto __y_use_tag =
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__use_alloc<_Tp2, memory_resource*, _Args2...>(this->resource());
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::new(__p) std::pair<_Tp1, _Tp2>(piecewise_construct,
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_M_construct_p(__x_use_tag, __x),
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_M_construct_p(__y_use_tag, __y));
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}
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template <typename _Tp1, typename _Tp2>
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void construct(pair<_Tp1,_Tp2>* __p)
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{ this->construct(__p, piecewise_construct, tuple<>(), tuple<>()); }
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template <typename _Tp1, typename _Tp2, typename _Up, typename _Vp>
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void construct(pair<_Tp1,_Tp2>* __p, _Up&& __x, _Vp&& __y)
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{ this->construct(__p, piecewise_construct,
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forward_as_tuple(std::forward<_Up>(__x)),
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forward_as_tuple(std::forward<_Vp>(__y))); }
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template <typename _Tp1, typename _Tp2, typename _Up, typename _Vp>
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void construct(pair<_Tp1,_Tp2>* __p, const std::pair<_Up, _Vp>& __pr)
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{ this->construct(__p, piecewise_construct, forward_as_tuple(__pr.first),
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forward_as_tuple(__pr.second)); }
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template <typename _Tp1, typename _Tp2, typename _Up, typename _Vp>
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void construct(pair<_Tp1,_Tp2>* __p, pair<_Up, _Vp>&& __pr)
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{ this->construct(__p, piecewise_construct,
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forward_as_tuple(std::forward<_Up>(__pr.first)),
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forward_as_tuple(std::forward<_Vp>(__pr.second))); }
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template <typename _Up>
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void destroy(_Up* __p)
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{ __p->~_Up(); }
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// Return a default-constructed allocator (no allocator propagation)
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polymorphic_allocator select_on_container_copy_construction() const
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{ return polymorphic_allocator(); }
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memory_resource* resource() const
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{ return _M_resource; }
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private:
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template<typename _Tuple>
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_Tuple&&
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_M_construct_p(__uses_alloc0, _Tuple& __t)
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{ return std::move(__t); }
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template<typename... _Args>
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decltype(auto)
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_M_construct_p(__uses_alloc1_ __ua, tuple<_Args...>& __t)
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{ return tuple_cat(make_tuple(allocator_arg, *(__ua._M_a)),
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std::move(__t)); }
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template<typename... _Args>
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decltype(auto)
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_M_construct_p(__uses_alloc2_ __ua, tuple<_Args...>& __t)
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{ return tuple_cat(std::move(__t), make_tuple(*(__ua._M_a))); }
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memory_resource* _M_resource;
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};
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template <class _Tp1, class _Tp2>
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bool operator==(const polymorphic_allocator<_Tp1>& __a,
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const polymorphic_allocator<_Tp2>& __b) noexcept
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{ return *__a.resource() == *__b.resource(); }
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template <class _Tp1, class _Tp2>
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bool operator!=(const polymorphic_allocator<_Tp1>& __a,
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const polymorphic_allocator<_Tp2>& __b) noexcept
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{ return !(__a == __b); }
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// 8.7.1 __resource_adaptor_imp
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template <typename _Alloc>
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class __resource_adaptor_imp : public memory_resource
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{
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public:
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using allocator_type = _Alloc;
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__resource_adaptor_imp() = default;
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__resource_adaptor_imp(const __resource_adaptor_imp&) = default;
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__resource_adaptor_imp(__resource_adaptor_imp&&) = default;
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explicit __resource_adaptor_imp(const _Alloc& __a2)
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: _M_alloc(__a2)
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{ }
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explicit __resource_adaptor_imp(_Alloc&& __a2)
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: _M_alloc(std::move(__a2))
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{ }
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__resource_adaptor_imp&
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operator=(const __resource_adaptor_imp&) = default;
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allocator_type get_allocator() const { return _M_alloc; }
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protected:
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virtual void*
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do_allocate(size_t __bytes, size_t __alignment)
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{
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using _Aligned_alloc = std::__alloc_rebind<_Alloc, char>;
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size_t __new_size = _S_aligned_size(__bytes,
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_S_supported(__alignment) ?
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__alignment : _S_max_align);
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return _Aligned_alloc(_M_alloc).allocate(__new_size);
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}
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virtual void
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do_deallocate(void* __p, size_t __bytes, size_t __alignment)
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{
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using _Aligned_alloc = std::__alloc_rebind<_Alloc, char>;
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size_t __new_size = _S_aligned_size(__bytes,
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_S_supported(__alignment) ?
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__alignment : _S_max_align);
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using _Ptr = typename allocator_traits<_Aligned_alloc>::pointer;
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_Aligned_alloc(_M_alloc).deallocate(static_cast<_Ptr>(__p),
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__new_size);
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}
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virtual bool
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do_is_equal(const memory_resource& __other) const noexcept
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{
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auto __p = dynamic_cast<const __resource_adaptor_imp*>(&__other);
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return __p ? (_M_alloc == __p->_M_alloc) : false;
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}
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private:
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// Calculate Aligned Size
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// Returns a size that is larger than or equal to __size and divisible
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// by __alignment, where __alignment is required to be the power of 2.
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static size_t
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_S_aligned_size(size_t __size, size_t __alignment)
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{ return ((__size - 1)|(__alignment - 1)) + 1; }
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// Determine whether alignment meets one of those preconditions:
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// 1. Equals to Zero
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// 2. Is power of two
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static bool
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_S_supported (size_t __x)
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{ return ((__x != 0) && !(__x & (__x - 1))); }
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_Alloc _M_alloc;
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};
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// Global memory resources
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inline std::atomic<memory_resource*>&
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__get_default_resource()
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{
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static atomic<memory_resource*> _S_default_resource(new_delete_resource());
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return _S_default_resource;
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}
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inline memory_resource*
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new_delete_resource() noexcept
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{
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static resource_adaptor<std::allocator<char>> __r;
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return static_cast<memory_resource*>(&__r);
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}
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template <typename _Alloc>
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class __null_memory_resource : private memory_resource
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{
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protected:
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void*
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do_allocate(size_t, size_t)
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{ std::__throw_bad_alloc(); }
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void
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do_deallocate(void*, size_t, size_t) noexcept
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{ }
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bool
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do_is_equal(const memory_resource& __other) const noexcept
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{ return this == &__other; }
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friend memory_resource* null_memory_resource() noexcept;
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};
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inline memory_resource*
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null_memory_resource() noexcept
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{
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static __null_memory_resource<void> __r;
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return static_cast<memory_resource*>(&__r);
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}
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// The default memory resource
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inline memory_resource*
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get_default_resource() noexcept
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{ return __get_default_resource().load(); }
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inline memory_resource*
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set_default_resource(memory_resource* __r) noexcept
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{
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if (__r == nullptr)
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__r = new_delete_resource();
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return __get_default_resource().exchange(__r);
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}
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_GLIBCXX_END_NAMESPACE_VERSION
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} // namespace pmr
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} // namespace fundamentals_v2
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} // namespace experimental
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} // namespace std
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#endif
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