gcc/libstdc++-v3/include/bits/allocated_ptr.h
Jonathan Wakely 2af96386a6 Define std::__to_address helper
* include/bits/allocated_ptr.h (__allocated_ptr::get): Use
	__to_address.
	(__allocated_ptr::_S_raw_ptr): Remove.
	* include/bits/forward_list.h (_Fwd_list_base::_M_get_node): Use
	__to_address.
	* include/bits/hashtable_policy.h (_Hashtable_alloc): Likewise.
	* include/bits/ptr_traits.h (__to_address): Define new function
	template.
	* include/bits/shared_ptr_base.h (__shared_ptr): Use __to_address.
	(__shared_ptr::_S_raw_ptr): Remove.
	* include/bits/stl_vector.h [__cplusplus >= 201103L]
	(vector::_M_data_ptr): Use __to_address.
	[__cplusplus < 201103L] (vector::_M_data_ptr): Don't dereference
	possibly invalid pointers.
	* include/ext/alloc_traits.h (__alloc_traits::construct)
	(__alloc_traits::destroy): Use __to_address.

From-SVN: r252055
2017-09-13 08:27:40 +01:00

105 lines
3.2 KiB
C++

// Guarded Allocation -*- C++ -*-
// Copyright (C) 2014-2017 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/** @file bits/allocated_ptr.h
* This is an internal header file, included by other library headers.
* Do not attempt to use it directly. @headername{memory}
*/
#ifndef _ALLOCATED_PTR_H
#define _ALLOCATED_PTR_H 1
#if __cplusplus < 201103L
# include <bits/c++0xwarning.h>
#else
# include <type_traits>
# include <bits/ptr_traits.h>
# include <bits/alloc_traits.h>
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/// Non-standard RAII type for managing pointers obtained from allocators.
template<typename _Alloc>
struct __allocated_ptr
{
using pointer = typename allocator_traits<_Alloc>::pointer;
using value_type = typename allocator_traits<_Alloc>::value_type;
/// Take ownership of __ptr
__allocated_ptr(_Alloc& __a, pointer __ptr) noexcept
: _M_alloc(std::__addressof(__a)), _M_ptr(__ptr)
{ }
/// Convert __ptr to allocator's pointer type and take ownership of it
template<typename _Ptr,
typename _Req = _Require<is_same<_Ptr, value_type*>>>
__allocated_ptr(_Alloc& __a, _Ptr __ptr)
: _M_alloc(std::__addressof(__a)),
_M_ptr(pointer_traits<pointer>::pointer_to(*__ptr))
{ }
/// Transfer ownership of the owned pointer
__allocated_ptr(__allocated_ptr&& __gd) noexcept
: _M_alloc(__gd._M_alloc), _M_ptr(__gd._M_ptr)
{ __gd._M_ptr = nullptr; }
/// Deallocate the owned pointer
~__allocated_ptr()
{
if (_M_ptr != nullptr)
std::allocator_traits<_Alloc>::deallocate(*_M_alloc, _M_ptr, 1);
}
/// Release ownership of the owned pointer
__allocated_ptr&
operator=(std::nullptr_t) noexcept
{
_M_ptr = nullptr;
return *this;
}
/// Get the address that the owned pointer refers to.
value_type* get() { return std::__to_address(_M_ptr); }
private:
_Alloc* _M_alloc;
pointer _M_ptr;
};
/// Allocate space for a single object using __a
template<typename _Alloc>
__allocated_ptr<_Alloc>
__allocate_guarded(_Alloc& __a)
{
return { __a, std::allocator_traits<_Alloc>::allocate(__a, 1) };
}
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
#endif
#endif