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// Guarded Allocation -*- C++ -*- |
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|
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// Copyright (C) 2014-2021 Free Software Foundation, Inc. |
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// |
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// This file is part of the GNU ISO C++ Library. This library is free |
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// software; you can redistribute it and/or modify it under the |
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// terms of the GNU General Public License as published by the |
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// Free Software Foundation; either version 3, or (at your option) |
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// any later version. |
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|
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// This library is distributed in the hope that it will be useful, |
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// but WITHOUT ANY WARRANTY; without even the implied warranty of |
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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// GNU General Public License for more details. |
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|
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// Under Section 7 of GPL version 3, you are granted additional |
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// permissions described in the GCC Runtime Library Exception, version |
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// 3.1, as published by the Free Software Foundation. |
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|
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// You should have received a copy of the GNU General Public License and |
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// a copy of the GCC Runtime Library Exception along with this program; |
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// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
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// <http://www.gnu.org/licenses/>. |
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|
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/** @file bits/allocated_ptr.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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|
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#ifndef _ALLOCATED_PTR_H |
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#define _ALLOCATED_PTR_H 1 |
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|
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#if __cplusplus < 201103L |
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# include <bits/c++0xwarning.h> |
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#else |
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# include <type_traits> |
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# include <bits/ptr_traits.h> |
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# include <bits/alloc_traits.h> |
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|
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namespace std _GLIBCXX_VISIBILITY(default) |
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{ |
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_GLIBCXX_BEGIN_NAMESPACE_VERSION |
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|
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/// Non-standard RAII type for managing pointers obtained from allocators. |
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template<typename _Alloc> |
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struct __allocated_ptr |
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{ |
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using pointer = typename allocator_traits<_Alloc>::pointer; |
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using value_type = typename allocator_traits<_Alloc>::value_type; |
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|
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/// Take ownership of __ptr |
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__allocated_ptr(_Alloc& __a, pointer __ptr) noexcept |
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: _M_alloc(std::__addressof(__a)), _M_ptr(__ptr) |
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{ } |
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|
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/// Convert __ptr to allocator's pointer type and take ownership of it |
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template<typename _Ptr, |
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typename _Req = _Require<is_same<_Ptr, value_type*>>> |
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__allocated_ptr(_Alloc& __a, _Ptr __ptr) |
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: _M_alloc(std::__addressof(__a)), |
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_M_ptr(pointer_traits<pointer>::pointer_to(*__ptr)) |
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{ } |
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|
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/// Transfer ownership of the owned pointer |
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__allocated_ptr(__allocated_ptr&& __gd) noexcept |
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: _M_alloc(__gd._M_alloc), _M_ptr(__gd._M_ptr) |
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{ __gd._M_ptr = nullptr; } |
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|
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/// Deallocate the owned pointer |
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~__allocated_ptr() |
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{ |
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if (_M_ptr != nullptr) |
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std::allocator_traits<_Alloc>::deallocate(*_M_alloc, _M_ptr, 1); |
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} |
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|
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/// Release ownership of the owned pointer |
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__allocated_ptr& |
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operator=(std::nullptr_t) noexcept |
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{ |
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_M_ptr = nullptr; |
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return *this; |
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} |
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|
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/// Get the address that the owned pointer refers to. |
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value_type* get() { return std::__to_address(_M_ptr); } |
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|
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private: |
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_Alloc* _M_alloc; |
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pointer _M_ptr; |
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}; |
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|
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/// Allocate space for a single object using __a |
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template<typename _Alloc> |
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__allocated_ptr<_Alloc> |
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__allocate_guarded(_Alloc& __a) |
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{ |
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return { __a, std::allocator_traits<_Alloc>::allocate(__a, 1) }; |
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} |
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|
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_GLIBCXX_END_NAMESPACE_VERSION |
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} // namespace std |
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|
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#endif |
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#endif |
