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       1             : // Allocator that wraps operator new -*- C++ -*-
       2             : 
       3             : // Copyright (C) 2001-2014 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/new_allocator.h
      26             :  *  This file is a GNU extension to the Standard C++ Library.
      27             :  */
      28             : 
      29             : #ifndef _NEW_ALLOCATOR_H
      30             : #define _NEW_ALLOCATOR_H 1
      31             : 
      32             : #include <bits/c++config.h>
      33             : #include <new>
      34             : #include <bits/functexcept.h>
      35             : #include <bits/move.h>
      36             : #if __cplusplus >= 201103L
      37             : #include <type_traits>
      38             : #endif
      39             : 
      40             : namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
      41             : {
      42             : _GLIBCXX_BEGIN_NAMESPACE_VERSION
      43             : 
      44             :   using std::size_t;
      45             :   using std::ptrdiff_t;
      46             : 
      47             :   /**
      48             :    *  @brief  An allocator that uses global new, as per [20.4].
      49             :    *  @ingroup allocators
      50             :    *
      51             :    *  This is precisely the allocator defined in the C++ Standard. 
      52             :    *    - all allocation calls operator new
      53             :    *    - all deallocation calls operator delete
      54             :    *
      55             :    *  @tparam  _Tp  Type of allocated object.
      56             :    */
      57             :   template<typename _Tp>
      58             :     class new_allocator
      59             :     {
      60             :     public:
      61             :       typedef size_t     size_type;
      62             :       typedef ptrdiff_t  difference_type;
      63             :       typedef _Tp*       pointer;
      64             :       typedef const _Tp* const_pointer;
      65             :       typedef _Tp&       reference;
      66             :       typedef const _Tp& const_reference;
      67             :       typedef _Tp        value_type;
      68             : 
      69             :       template<typename _Tp1>
      70             :         struct rebind
      71             :         { typedef new_allocator<_Tp1> other; };
      72             : 
      73             : #if __cplusplus >= 201103L
      74             :       // _GLIBCXX_RESOLVE_LIB_DEFECTS
      75             :       // 2103. propagate_on_container_move_assignment
      76             :       typedef std::true_type propagate_on_container_move_assignment;
      77             : #endif
      78             : 
      79         166 :       new_allocator() _GLIBCXX_USE_NOEXCEPT { }
      80             : 
      81         117 :       new_allocator(const new_allocator&) _GLIBCXX_USE_NOEXCEPT { }
      82             : 
      83             :       template<typename _Tp1>
      84             :         new_allocator(const new_allocator<_Tp1>&) _GLIBCXX_USE_NOEXCEPT { }
      85             : 
      86         283 :       ~new_allocator() _GLIBCXX_USE_NOEXCEPT { }
      87             : 
      88             :       pointer
      89             :       address(reference __x) const _GLIBCXX_NOEXCEPT
      90             :       { return std::__addressof(__x); }
      91             : 
      92             :       const_pointer
      93             :       address(const_reference __x) const _GLIBCXX_NOEXCEPT
      94             :       { return std::__addressof(__x); }
      95             : 
      96             :       // NB: __n is permitted to be 0.  The C++ standard says nothing
      97             :       // about what the return value is when __n == 0.
      98             :       pointer
      99         163 :       allocate(size_type __n, const void* = 0)
     100             :       { 
     101         163 :         if (__n > this->max_size())
     102           0 :           std::__throw_bad_alloc();
     103             : 
     104         163 :         return static_cast<_Tp*>(::operator new(__n * sizeof(_Tp)));
     105             :       }
     106             : 
     107             :       // __p is not permitted to be a null pointer.
     108             :       void
     109         163 :       deallocate(pointer __p, size_type)
     110         163 :       { ::operator delete(__p); }
     111             : 
     112             :       size_type
     113         324 :       max_size() const _GLIBCXX_USE_NOEXCEPT
     114         324 :       { return size_t(-1) / sizeof(_Tp); }
     115             : 
     116             : #if __cplusplus >= 201103L
     117             :       template<typename _Up, typename... _Args>
     118             :         void
     119         120 :         construct(_Up* __p, _Args&&... __args)
     120         120 :         { ::new((void *)__p) _Up(std::forward<_Args>(__args)...); }
     121             : 
     122             :       template<typename _Up>
     123             :         void 
     124          36 :         destroy(_Up* __p) { __p->~_Up(); }
     125             : #else
     126             :       // _GLIBCXX_RESOLVE_LIB_DEFECTS
     127             :       // 402. wrong new expression in [some_] allocator::construct
     128             :       void 
     129             :       construct(pointer __p, const _Tp& __val) 
     130             :       { ::new((void *)__p) _Tp(__val); }
     131             : 
     132             :       void 
     133             :       destroy(pointer __p) { __p->~_Tp(); }
     134             : #endif
     135             :     };
     136             : 
     137             :   template<typename _Tp>
     138             :     inline bool
     139             :     operator==(const new_allocator<_Tp>&, const new_allocator<_Tp>&)
     140             :     { return true; }
     141             :   
     142             :   template<typename _Tp>
     143             :     inline bool
     144             :     operator!=(const new_allocator<_Tp>&, const new_allocator<_Tp>&)
     145             :     { return false; }
     146             : 
     147             : _GLIBCXX_END_NAMESPACE_VERSION
     148             : } // namespace
     149             : 
     150             : #endif