contrib/gcc-4.4/libstdc++-v3/include/ext/new_allocator.h

   1 // Allocator that wraps operator new -*- C++ -*-
   2
   3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2009
   4 // Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 3, or (at your option)
  10 // any later version.
  11
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16
  17 // Under Section 7 of GPL version 3, you are granted additional
  18 // permissions described in the GCC Runtime Library Exception, version
  19 // 3.1, as published by the Free Software Foundation.
  20
  21 // You should have received a copy of the GNU General Public License and
  22 // a copy of the GCC Runtime Library Exception along with this program;
  23 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 // <http://www.gnu.org/licenses/>.
  25
  26 /** @file ext/new_allocator.h
  27  *  This file is a GNU extension to the Standard C++ Library.
  28  */
  29
  30 #ifndef _NEW_ALLOCATOR_H
  31 #define _NEW_ALLOCATOR_H 1
  32
  33 #include <new>
  34 #include <bits/functexcept.h>
  35 #include <bits/move.h>
  36
  37 _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
  38
  39   using std::size_t;
  40   using std::ptrdiff_t;
  41
  42   /**
  43    *  @brief  An allocator that uses global new, as per [20.4].
  44    *  @ingroup allocators
  45    *
  46    *  This is precisely the allocator defined in the C++ Standard.
  47    *    - all allocation calls operator new
  48    *    - all deallocation calls operator delete
  49    */
  50   template<typename _Tp>
  51     class new_allocator
  52     {
  53     public:
  54       typedef size_t     size_type;
  55       typedef ptrdiff_t  difference_type;
  56       typedef _Tp*       pointer;
  57       typedef const _Tp* const_pointer;
  58       typedef _Tp&       reference;
  59       typedef const _Tp& const_reference;
  60       typedef _Tp        value_type;
  61
  62       template<typename _Tp1>
  63         struct rebind
  64         { typedef new_allocator<_Tp1> other; };
  65
  66       new_allocator() throw() { }
  67
  68       new_allocator(const new_allocator&) throw() { }
  69
  70       template<typename _Tp1>
  71         new_allocator(const new_allocator<_Tp1>&) throw() { }
  72
  73       ~new_allocator() throw() { }
  74
  75       pointer
  76       address(reference __x) const { return &__x; }
  77
  78       const_pointer
  79       address(const_reference __x) const { return &__x; }
  80
  81       // NB: __n is permitted to be 0.  The C++ standard says nothing
  82       // about what the return value is when __n == 0.
  83       pointer
  84       allocate(size_type __n, const void* = 0)
  85       {
  86         if (__builtin_expect(__n > this->max_size(), false))
  87           std::__throw_bad_alloc();
  88
  89         return static_cast<_Tp*>(::operator new(__n * sizeof(_Tp)));
  90       }
  91
  92       // __p is not permitted to be a null pointer.
  93       void
  94       deallocate(pointer __p, size_type)
  95       { ::operator delete(__p); }
  96
  97       size_type
  98       max_size() const throw()
  99       { return size_t(-1) / sizeof(_Tp); }
 100
 101       // _GLIBCXX_RESOLVE_LIB_DEFECTS
 102       // 402. wrong new expression in [some_] allocator::construct
 103       void
 104       construct(pointer __p, const _Tp& __val)
 105       { ::new((void *)__p) _Tp(__val); }
 106
 107 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 108       template<typename... _Args>
 109         void
 110         construct(pointer __p, _Args&&... __args)
 111         { ::new((void *)__p) _Tp(std::forward<_Args>(__args)...); }
 112 #endif
 113
 114       void
 115       destroy(pointer __p) { __p->~_Tp(); }
 116     };
 117
 118   template<typename _Tp>
 119     inline bool
 120     operator==(const new_allocator<_Tp>&, const new_allocator<_Tp>&)
 121     { return true; }
 122
 123   template<typename _Tp>
 124     inline bool
 125     operator!=(const new_allocator<_Tp>&, const new_allocator<_Tp>&)
 126     { return false; }
 127
 128 _GLIBCXX_END_NAMESPACE
 129
 130 #endif