111 lines
3.4 KiB
C++
111 lines
3.4 KiB
C++
// Guarded Allocation -*- C++ -*-
|
|
|
|
// Copyright (C) 2014-2015 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 _S_raw_ptr(_M_ptr); }
|
|
|
|
private:
|
|
value_type* _S_raw_ptr(value_type* __ptr) { return __ptr; }
|
|
|
|
template<typename _Ptr>
|
|
auto _S_raw_ptr(_Ptr __ptr) -> decltype(_S_raw_ptr(__ptr.operator->()))
|
|
{ return _S_raw_ptr(__ptr.operator->()); }
|
|
|
|
_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
|