release/src-rt-6.x.4708/toolchains/hndtools-arm-linux-2.6.36-uclibc-4.5.3/arm-brcm-linux-uclibcgnueabi/include/c++/4.5.3/bits/stl_tempbuf.h

   1 // Temporary buffer implementation -*- C++ -*-
   2
   3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
   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 /*
  27  *
  28  * Copyright (c) 1994
  29  * Hewlett-Packard Company
  30  *
  31  * Permission to use, copy, modify, distribute and sell this software
  32  * and its documentation for any purpose is hereby granted without fee,
  33  * provided that the above copyright notice appear in all copies and
  34  * that both that copyright notice and this permission notice appear
  35  * in supporting documentation.  Hewlett-Packard Company makes no
  36  * representations about the suitability of this software for any
  37  * purpose.  It is provided "as is" without express or implied warranty.
  38  *
  39  *
  40  * Copyright (c) 1996,1997
  41  * Silicon Graphics Computer Systems, Inc.
  42  *
  43  * Permission to use, copy, modify, distribute and sell this software
  44  * and its documentation for any purpose is hereby granted without fee,
  45  * provided that the above copyright notice appear in all copies and
  46  * that both that copyright notice and this permission notice appear
  47  * in supporting documentation.  Silicon Graphics makes no
  48  * representations about the suitability of this software for any
  49  * purpose.  It is provided "as is" without express or implied warranty.
  50  */
  51
  52 /** @file stl_tempbuf.h
  53  *  This is an internal header file, included by other library headers.
  54  *  You should not attempt to use it directly.
  55  */
  56
  57 #ifndef _STL_TEMPBUF_H
  58 #define _STL_TEMPBUF_H 1
  59
  60 #include <bits/stl_algobase.h>
  61 #include <bits/stl_construct.h>
  62 #include <bits/stl_uninitialized.h>
  63
  64 _GLIBCXX_BEGIN_NAMESPACE(std)
  65
  66   /**
  67    *  @brief Allocates a temporary buffer.
  68    *  @param  len  The number of objects of type Tp.
  69    *  @return See full description.
  70    *
  71    *  Reinventing the wheel, but this time with prettier spokes!
  72    *
  73    *  This function tries to obtain storage for @c len adjacent Tp
  74    *  objects.  The objects themselves are not constructed, of course.
  75    *  A pair<> is returned containing <em>the buffer s address and
  76    *  capacity (in the units of sizeof(Tp)), or a pair of 0 values if
  77    *  no storage can be obtained.</em>  Note that the capacity obtained
  78    *  may be less than that requested if the memory is unavailable;
  79    *  you should compare len with the .second return value.
  80    *
  81    * Provides the nothrow exception guarantee.
  82    */
  83   template<typename _Tp>
  84     pair<_Tp*, ptrdiff_t>
  85     get_temporary_buffer(ptrdiff_t __len)
  86     {
  87       const ptrdiff_t __max =
  88         __gnu_cxx::__numeric_traits<ptrdiff_t>::__max / sizeof(_Tp);
  89       if (__len > __max)
  90         __len = __max;
  91
  92       while (__len > 0)
  93         {
  94           _Tp* __tmp = static_cast<_Tp*>(::operator new(__len * sizeof(_Tp),
  95                                                         std::nothrow));
  96           if (__tmp != 0)
  97             return std::pair<_Tp*, ptrdiff_t>(__tmp, __len);
  98           __len /= 2;
  99         }
 100       return std::pair<_Tp*, ptrdiff_t>(static_cast<_Tp*>(0), 0);
 101     }
 102
 103   /**
 104    *  @brief The companion to get_temporary_buffer().
 105    *  @param  p  A buffer previously allocated by get_temporary_buffer.
 106    *  @return   None.
 107    *
 108    *  Frees the memory pointed to by p.
 109    */
 110   template<typename _Tp>
 111     inline void
 112     return_temporary_buffer(_Tp* __p)
 113     { ::operator delete(__p, std::nothrow); }
 114
 115
 116   /**
 117    *  This class is used in two places: stl_algo.h and ext/memory,
 118    *  where it is wrapped as the temporary_buffer class.  See
 119    *  temporary_buffer docs for more notes.
 120    */
 121   template<typename _ForwardIterator, typename _Tp>
 122     class _Temporary_buffer
 123     {
 124       // concept requirements
 125       __glibcxx_class_requires(_ForwardIterator, _ForwardIteratorConcept)
 126
 127     public:
 128       typedef _Tp         value_type;
 129       typedef value_type* pointer;
 130       typedef pointer     iterator;
 131       typedef ptrdiff_t   size_type;
 132
 133     protected:
 134       size_type  _M_original_len;
 135       size_type  _M_len;
 136       pointer    _M_buffer;
 137
 138     public:
 139       /// As per Table mumble.
 140       size_type
 141       size() const
 142       { return _M_len; }
 143
 144       /// Returns the size requested by the constructor; may be >size().
 145       size_type
 146       requested_size() const
 147       { return _M_original_len; }
 148
 149       /// As per Table mumble.
 150       iterator
 151       begin()
 152       { return _M_buffer; }
 153
 154       /// As per Table mumble.
 155       iterator
 156       end()
 157       { return _M_buffer + _M_len; }
 158
 159       /**
 160        * Constructs a temporary buffer of a size somewhere between
 161        * zero and the size of the given range.
 162        */
 163       _Temporary_buffer(_ForwardIterator __first, _ForwardIterator __last);
 164
 165       ~_Temporary_buffer()
 166       {
 167         std::_Destroy(_M_buffer, _M_buffer + _M_len);
 168         std::return_temporary_buffer(_M_buffer);
 169       }
 170
 171     private:
 172       // Disable copy constructor and assignment operator.
 173       _Temporary_buffer(const _Temporary_buffer&);
 174
 175       void
 176       operator=(const _Temporary_buffer&);
 177     };
 178
 179   template<typename _ForwardIterator, typename _Tp>
 180     _Temporary_buffer<_ForwardIterator, _Tp>::
 181     _Temporary_buffer(_ForwardIterator __first, _ForwardIterator __last)
 182     : _M_original_len(std::distance(__first, __last)),
 183       _M_len(0), _M_buffer(0)
 184     {
 185       __try
 186         {
 187           std::pair<pointer, size_type> __p(std::get_temporary_buffer<
 188                                             value_type>(_M_original_len));
 189           _M_buffer = __p.first;
 190           _M_len = __p.second;
 191           if(_M_buffer)
 192             std::__uninitialized_construct_range(_M_buffer, _M_buffer + _M_len,
 193                                                  *__first);
 194         }
 195       __catch(...)
 196         {
 197           std::return_temporary_buffer(_M_buffer);
 198           _M_buffer = 0;
 199           _M_len = 0;
 200           __throw_exception_again;
 201         }
 202     }
 203
 204 _GLIBCXX_END_NAMESPACE
 205
 206 #endif /* _STL_TEMPBUF_H */
 207