# new_allocator.h

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    00001 // Allocator that wraps operator new -*- C++ -*-
    00002
    00003 // Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
    00004 //
    00005 // This file is part of the GNU ISO C++ Library.  This library is free
    00006 // software; you can redistribute it and/or modify it under the
    00007 // terms of the GNU General Public License as published by the
    00008 // Free Software Foundation; either version 2, or (at your option)
    00009 // any later version.
    00010
    00011 // This library is distributed in the hope that it will be useful,
    00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of
    00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00014 // GNU General Public License for more details.
    00015
    00016 // You should have received a copy of the GNU General Public License along
    00017 // with this library; see the file COPYING.  If not, write to the Free
    00018 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
    00019 // USA.
    00020
    00021 // As a special exception, you may use this file as part of a free software
    00022 // library without restriction.  Specifically, if other files instantiate
    00023 // templates or use macros or inline functions from this file, or you compile
    00024 // this file and link it with other files to produce an executable, this
    00025 // file does not by itself cause the resulting executable to be covered by
    00026 // the GNU General Public License.  This exception does not however
    00027 // invalidate any other reasons why the executable file might be covered by
    00028 // the GNU General Public License.
    00029
    00030 /** @file ext/new_allocator.h
    00031  *  This file is a GNU extension to the Standard C++ Library.
    00032  */
    00033
    00034 #ifndef _NEW_ALLOCATOR_H
    00035 #define _NEW_ALLOCATOR_H 1
    00036
    00037 #include <new>
    00038 #include <bits/functexcept.h>
    00039
    00040 _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
    00041
    00042   using std::size_t;
    00043   using std::ptrdiff_t;
    00044
    00045   /**
    00046    *  @brief  An allocator that uses global new, as per [20.4].
    00047    *
    00048    *  This is precisely the allocator defined in the C++ Standard.
    00049    *    - all allocation calls operator new
    00050    *    - all deallocation calls operator delete
    00051    */
    00052   template<typename _Tp>
    00053     class new_allocator
    00054     {
    00055     public:
    00056       typedef size_t     size_type;
    00057       typedef ptrdiff_t  difference_type;
    00058       typedef _Tp*       pointer;
    00059       typedef const _Tp* const_pointer;
    00060       typedef _Tp&       reference;
    00061       typedef const _Tp& const_reference;
    00062       typedef _Tp        value_type;
    00063
    00064       template<typename _Tp1>
    00065         struct rebind
    00066         { typedef new_allocator<_Tp1> other; };
    00067
    00068       new_allocator() throw() { }
    00069
    00070       new_allocator(const new_allocator&) throw() { }
    00071
    00072       template<typename _Tp1>
    00073         new_allocator(const new_allocator<_Tp1>&) throw() { }
    00074
    00075       ~new_allocator() throw() { }
    00076
    00077       pointer
    00078       address(reference __x) const { return &__x; }
    00079
    00080       const_pointer
    00081       address(const_reference __x) const { return &__x; }
    00082
    00083       // NB: __n is permitted to be 0.  The C++ standard says nothing
    00084       // about what the return value is when __n == 0.
    00085       pointer
    00086       allocate(size_type __n, const void* = 0)
    00087       {
    00088     if (__builtin_expect(__n > this->max_size(), false))
    00089       std::__throw_bad_alloc();
    00090
    00091     return static_cast<_Tp*>(::operator new(__n * sizeof(_Tp)));
    00092       }
    00093
    00094       // __p is not permitted to be a null pointer.
    00095       void
    00096       deallocate(pointer __p, size_type)
    00097       { ::operator delete(__p); }
    00098
    00099       size_type
    00100       max_size() const throw()
    00101       { return size_t(-1) / sizeof(_Tp); }
    00102
    00103       // _GLIBCXX_RESOLVE_LIB_DEFECTS
    00104       // 402. wrong new expression in [some_] allocator::construct
    00105       void
    00106       construct(pointer __p, const _Tp& __val)
    00107       { ::new(__p) _Tp(__val); }
    00108
    00109       void
    00110       destroy(pointer __p) { __p->~_Tp(); }
    00111     };
    00112
    00113   template<typename _Tp>
    00114     inline bool
    00115     operator==(const new_allocator<_Tp>&, const new_allocator<_Tp>&)
    00116     { return true; }
    00117
    00118   template<typename _Tp>
    00119     inline bool
    00120     operator!=(const new_allocator<_Tp>&, const new_allocator<_Tp>&)
    00121     { return false; }
    00122
    00123 _GLIBCXX_END_NAMESPACE
    00124
    00125 #endif