mirror of git://gcc.gnu.org/git/gcc.git
629 lines
20 KiB
C++
629 lines
20 KiB
C++
// Allocator traits -*- C++ -*-
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// Copyright (C) 2011-2019 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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#if __cplusplus >= 201103L
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#include <bits/memoryfwd.h>
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#include <bits/ptr_traits.h>
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#include <ext/numeric_traits.h>
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#define __cpp_lib_allocator_traits_is_always_equal 201411
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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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struct __allocator_traits_base
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{
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template<typename _Tp, typename _Up, typename = void>
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struct __rebind : __replace_first_arg<_Tp, _Up> { };
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template<typename _Tp, typename _Up>
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struct __rebind<_Tp, _Up,
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__void_t<typename _Tp::template rebind<_Up>::other>>
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{ using type = typename _Tp::template rebind<_Up>::other; };
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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 = typename _Tp::is_always_equal;
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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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/**
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* @brief Uniform interface to all allocator types.
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* @ingroup allocators
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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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= __detected_or_t<typename is_empty<_Alloc>::type, __equal, _Alloc>;
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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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private:
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template<typename _Alloc2>
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static auto
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_S_allocate(_Alloc2& __a, size_type __n, const_void_pointer __hint, int)
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-> decltype(__a.allocate(__n, __hint))
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{ return __a.allocate(__n, __hint); }
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template<typename _Alloc2>
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static pointer
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_S_allocate(_Alloc2& __a, size_type __n, const_void_pointer, ...)
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{ return __a.allocate(__n); }
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template<typename _Tp, typename... _Args>
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struct __construct_helper
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{
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template<typename _Alloc2,
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typename = decltype(std::declval<_Alloc2*>()->construct(
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std::declval<_Tp*>(), std::declval<_Args>()...))>
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static true_type __test(int);
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template<typename>
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static false_type __test(...);
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using type = decltype(__test<_Alloc>(0));
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};
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template<typename _Tp, typename... _Args>
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using __has_construct
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= typename __construct_helper<_Tp, _Args...>::type;
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template<typename _Tp, typename... _Args>
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static _Require<__has_construct<_Tp, _Args...>>
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_S_construct(_Alloc& __a, _Tp* __p, _Args&&... __args)
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noexcept(noexcept(__a.construct(__p, std::forward<_Args>(__args)...)))
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{ __a.construct(__p, std::forward<_Args>(__args)...); }
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template<typename _Tp, typename... _Args>
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static
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_Require<__and_<__not_<__has_construct<_Tp, _Args...>>,
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is_constructible<_Tp, _Args...>>>
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_S_construct(_Alloc&, _Tp* __p, _Args&&... __args)
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noexcept(noexcept(::new((void*)__p)
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_Tp(std::forward<_Args>(__args)...)))
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{ ::new((void*)__p) _Tp(std::forward<_Args>(__args)...); }
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template<typename _Alloc2, typename _Tp>
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static auto
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_S_destroy(_Alloc2& __a, _Tp* __p, int)
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noexcept(noexcept(__a.destroy(__p)))
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-> decltype(__a.destroy(__p))
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{ __a.destroy(__p); }
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template<typename _Alloc2, typename _Tp>
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static void
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_S_destroy(_Alloc2&, _Tp* __p, ...)
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noexcept(noexcept(__p->~_Tp()))
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{ __p->~_Tp(); }
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template<typename _Alloc2>
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static auto
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_S_max_size(_Alloc2& __a, int)
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-> decltype(__a.max_size())
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{ return __a.max_size(); }
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template<typename _Alloc2>
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static size_type
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_S_max_size(_Alloc2&, ...)
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{
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// _GLIBCXX_RESOLVE_LIB_DEFECTS
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// 2466. allocator_traits::max_size() default behavior is incorrect
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return __gnu_cxx::__numeric_traits<size_type>::__max
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/ sizeof(value_type);
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}
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template<typename _Alloc2>
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static auto
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_S_select(_Alloc2& __a, int)
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-> decltype(__a.select_on_container_copy_construction())
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{ return __a.select_on_container_copy_construction(); }
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template<typename _Alloc2>
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static _Alloc2
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_S_select(_Alloc2& __a, ...)
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{ return __a; }
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public:
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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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static 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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static pointer
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allocate(_Alloc& __a, size_type __n, const_void_pointer __hint)
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{ return _S_allocate(__a, __n, __hint, 0); }
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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 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 @a _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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static auto construct(_Alloc& __a, _Tp* __p, _Args&&... __args)
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noexcept(noexcept(_S_construct(__a, __p,
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std::forward<_Args>(__args)...)))
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-> decltype(_S_construct(__a, __p, std::forward<_Args>(__args)...))
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{ _S_construct(__a, __p, std::forward<_Args>(__args)...); }
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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 void destroy(_Alloc& __a, _Tp* __p)
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noexcept(noexcept(_S_destroy(__a, __p, 0)))
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{ _S_destroy(__a, __p, 0); }
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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 size_type max_size(const _Alloc& __a) noexcept
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{ return _S_max_size(__a, 0); }
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/**
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* @brief Obtain an allocator to use when copying a container.
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* @param __rhs An allocator.
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* @return @c __rhs.select_on_container_copy_construction() or @a __rhs
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*
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* Returns @c __rhs.select_on_container_copy_construction() if that
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* expression is well-formed, otherwise returns @a __rhs
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*/
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static _Alloc
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select_on_container_copy_construction(const _Alloc& __rhs)
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{ return _S_select(__rhs, 0); }
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};
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/// Partial specialization for std::allocator.
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template<typename _Tp>
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struct allocator_traits<allocator<_Tp>>
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{
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/// The allocator type
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using allocator_type = allocator<_Tp>;
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/// The allocated type
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using value_type = _Tp;
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/// The allocator's pointer type.
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using pointer = _Tp*;
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/// The allocator's const pointer type.
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using const_pointer = const _Tp*;
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/// The allocator's void pointer type.
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using void_pointer = void*;
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/// The allocator's const void pointer type.
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using const_void_pointer = const void*;
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/// The allocator's difference type
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using difference_type = std::ptrdiff_t;
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/// The allocator's size type
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using size_type = std::size_t;
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/// How the allocator is propagated on copy assignment
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using propagate_on_container_copy_assignment = false_type;
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/// How the allocator is propagated on move assignment
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using propagate_on_container_move_assignment = true_type;
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/// How the allocator is propagated on swap
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using propagate_on_container_swap = false_type;
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/// Whether all instances of the allocator type compare equal.
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using is_always_equal = true_type;
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template<typename _Up>
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using rebind_alloc = allocator<_Up>;
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template<typename _Up>
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using rebind_traits = allocator_traits<allocator<_Up>>;
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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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static pointer
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allocate(allocator_type& __a, size_type __n)
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{ return __a.allocate(__n); }
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|
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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>
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*/
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static pointer
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allocate(allocator_type& __a, size_type __n, const_void_pointer __hint)
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{ return __a.allocate(__n, __hint); }
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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 void
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deallocate(allocator_type& __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 @a _Up
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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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*/
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template<typename _Up, typename... _Args>
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static void
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construct(allocator_type& __a, _Up* __p, _Args&&... __args)
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noexcept(noexcept(__a.construct(__p, std::forward<_Args>(__args)...)))
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{ __a.construct(__p, std::forward<_Args>(__args)...); }
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/**
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* @brief Destroy an object of type @a _Up
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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).
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*/
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template<typename _Up>
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static void
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destroy(allocator_type& __a, _Up* __p)
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noexcept(noexcept(__a.destroy(__p)))
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{ __a.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()
|
|
*/
|
|
static size_type
|
|
max_size(const allocator_type& __a) noexcept
|
|
{ return __a.max_size(); }
|
|
|
|
/**
|
|
* @brief Obtain an allocator to use when copying a container.
|
|
* @param __rhs An allocator.
|
|
* @return @c __rhs
|
|
*/
|
|
static allocator_type
|
|
select_on_container_copy_construction(const allocator_type& __rhs)
|
|
{ return __rhs; }
|
|
};
|
|
|
|
|
|
template<typename _Alloc>
|
|
inline void
|
|
__do_alloc_on_copy(_Alloc& __one, const _Alloc& __two, true_type)
|
|
{ __one = __two; }
|
|
|
|
template<typename _Alloc>
|
|
inline void
|
|
__do_alloc_on_copy(_Alloc&, const _Alloc&, false_type)
|
|
{ }
|
|
|
|
template<typename _Alloc>
|
|
inline void __alloc_on_copy(_Alloc& __one, const _Alloc& __two)
|
|
{
|
|
typedef allocator_traits<_Alloc> __traits;
|
|
typedef typename __traits::propagate_on_container_copy_assignment __pocca;
|
|
__do_alloc_on_copy(__one, __two, __pocca());
|
|
}
|
|
|
|
template<typename _Alloc>
|
|
inline _Alloc __alloc_on_copy(const _Alloc& __a)
|
|
{
|
|
typedef allocator_traits<_Alloc> __traits;
|
|
return __traits::select_on_container_copy_construction(__a);
|
|
}
|
|
|
|
template<typename _Alloc>
|
|
inline void __do_alloc_on_move(_Alloc& __one, _Alloc& __two, true_type)
|
|
{ __one = std::move(__two); }
|
|
|
|
template<typename _Alloc>
|
|
inline void __do_alloc_on_move(_Alloc&, _Alloc&, false_type)
|
|
{ }
|
|
|
|
template<typename _Alloc>
|
|
inline void __alloc_on_move(_Alloc& __one, _Alloc& __two)
|
|
{
|
|
typedef allocator_traits<_Alloc> __traits;
|
|
typedef typename __traits::propagate_on_container_move_assignment __pocma;
|
|
__do_alloc_on_move(__one, __two, __pocma());
|
|
}
|
|
|
|
template<typename _Alloc>
|
|
inline void __do_alloc_on_swap(_Alloc& __one, _Alloc& __two, true_type)
|
|
{
|
|
using std::swap;
|
|
swap(__one, __two);
|
|
}
|
|
|
|
template<typename _Alloc>
|
|
inline void __do_alloc_on_swap(_Alloc&, _Alloc&, false_type)
|
|
{ }
|
|
|
|
template<typename _Alloc>
|
|
inline void __alloc_on_swap(_Alloc& __one, _Alloc& __two)
|
|
{
|
|
typedef allocator_traits<_Alloc> __traits;
|
|
typedef typename __traits::propagate_on_container_swap __pocs;
|
|
__do_alloc_on_swap(__one, __two, __pocs());
|
|
}
|
|
|
|
template<typename _Alloc>
|
|
class __is_copy_insertable_impl
|
|
{
|
|
typedef allocator_traits<_Alloc> _Traits;
|
|
|
|
template<typename _Up, typename
|
|
= decltype(_Traits::construct(std::declval<_Alloc&>(),
|
|
std::declval<_Up*>(),
|
|
std::declval<const _Up&>()))>
|
|
static true_type
|
|
_M_select(int);
|
|
|
|
template<typename _Up>
|
|
static false_type
|
|
_M_select(...);
|
|
|
|
public:
|
|
typedef decltype(_M_select<typename _Alloc::value_type>(0)) type;
|
|
};
|
|
|
|
// true if _Alloc::value_type is CopyInsertable into containers using _Alloc
|
|
template<typename _Alloc>
|
|
struct __is_copy_insertable
|
|
: __is_copy_insertable_impl<_Alloc>::type
|
|
{ };
|
|
|
|
// std::allocator<_Tp> just requires CopyConstructible
|
|
template<typename _Tp>
|
|
struct __is_copy_insertable<allocator<_Tp>>
|
|
: is_copy_constructible<_Tp>
|
|
{ };
|
|
|
|
// 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;
|
|
|
|
_GLIBCXX_END_NAMESPACE_VERSION
|
|
} // namespace std
|
|
#endif // C++11
|
|
#endif // _ALLOC_TRAITS_H
|