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Diffstat (limited to 'libstdc++-v3/include/bits/allocated_ptr.h')
-rw-r--r-- | libstdc++-v3/include/bits/allocated_ptr.h | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/libstdc++-v3/include/bits/allocated_ptr.h b/libstdc++-v3/include/bits/allocated_ptr.h new file mode 100644 index 0000000..5cdce20 --- /dev/null +++ b/libstdc++-v3/include/bits/allocated_ptr.h @@ -0,0 +1,104 @@ +// Guarded Allocation -*- C++ -*- + +// Copyright (C) 2014 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(&__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(&__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; } + + /// 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 |