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       1             : // Aligned memory buffer -*- C++ -*-
       2             : 
       3             : // Copyright (C) 2013-2014 Free Software Foundation, Inc.
       4             : //
       5             : // This file is part of the GNU ISO C++ Library.  This library is free
       6             : // software; you can redistribute it and/or modify it under the
       7             : // terms of the GNU General Public License as published by the
       8             : // Free Software Foundation; either version 3, or (at your option)
       9             : // any later version.
      10             : 
      11             : // This library is distributed in the hope that it will be useful,
      12             : // but WITHOUT ANY WARRANTY; without even the implied warranty of
      13             : // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      14             : // GNU General Public License for more details.
      15             : 
      16             : // Under Section 7 of GPL version 3, you are granted additional
      17             : // permissions described in the GCC Runtime Library Exception, version
      18             : // 3.1, as published by the Free Software Foundation.
      19             : 
      20             : // You should have received a copy of the GNU General Public License and
      21             : // a copy of the GCC Runtime Library Exception along with this program;
      22             : // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
      23             : // <http://www.gnu.org/licenses/>.
      24             : 
      25             : /** @file ext/aligned_buffer.h
      26             :  *  This file is a GNU extension to the Standard C++ Library.
      27             :  */
      28             : 
      29             : #ifndef _ALIGNED_BUFFER_H
      30             : #define _ALIGNED_BUFFER_H 1
      31             : 
      32             : #pragma GCC system_header
      33             : 
      34             : #if __cplusplus >= 201103L
      35             : # include <type_traits>
      36             : #else
      37             : # include <bits/c++0x_warning.h>
      38             : #endif
      39             : 
      40             : namespace __gnu_cxx
      41             : {
      42             :   template<typename _Tp>
      43             :     struct __aligned_buffer
      44             :     : std::aligned_storage<sizeof(_Tp), std::alignment_of<_Tp>::value>
      45             :     {
      46             :       typename
      47             :         std::aligned_storage<sizeof(_Tp), std::alignment_of<_Tp>::value>::type
      48             :         _M_storage;
      49             : 
      50             :       void*
      51           0 :       _M_addr() noexcept
      52             :       {
      53           0 :         return static_cast<void*>(&_M_storage);
      54             :       }
      55             : 
      56             :       const void*
      57           0 :       _M_addr() const noexcept
      58             :       {
      59           0 :         return static_cast<const void*>(&_M_storage);
      60             :       }
      61             : 
      62             :       _Tp*
      63           0 :       _M_ptr() noexcept
      64           0 :       { return static_cast<_Tp*>(_M_addr()); }
      65             : 
      66             :       const _Tp*
      67           0 :       _M_ptr() const noexcept
      68           0 :       { return static_cast<const _Tp*>(_M_addr()); }
      69             :     };
      70             : 
      71             : } // namespace
      72             : 
      73             : #endif /* _ALIGNED_BUFFER_H */