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The C and C++ Include Header Files

/usr/include/c++/11/ext/debug_allocator.h


$ cat -n /usr/include/c++/11/ext/debug_allocator.h

     1	// Allocators -*- C++ -*-
     2	
     3	// Copyright (C) 2001-2021 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	/*
    26	 * Copyright (c) 1996-1997
    27	 * Silicon Graphics Computer Systems, Inc.
    28	 *
    29	 * Permission to use, copy, modify, distribute and sell this software
    30	 * and its documentation for any purpose is hereby granted without fee,
    31	 * provided that the above copyright notice appear in all copies and
    32	 * that both that copyright notice and this permission notice appear
    33	 * in supporting documentation.  Silicon Graphics makes no
    34	 * representations about the suitability of this software for any
    35	 * purpose.  It is provided "as is" without express or implied warranty.
    36	 */
    37	
    38	/** @file ext/debug_allocator.h
    39	 *  This file is a GNU extension to the Standard C++ Library.
    40	 */
    41	
    42	#ifndef _DEBUG_ALLOCATOR_H
    43	#define _DEBUG_ALLOCATOR_H 1
    44	
    45	#include <stdexcept>
    46	#include <bits/functexcept.h>
    47	#include <ext/alloc_traits.h>
    48	
    49	namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
    50	{
    51	_GLIBCXX_BEGIN_NAMESPACE_VERSION
    52	
    53	  /**
    54	   *  @brief  A meta-allocator with debugging bits.
    55	   *  @ingroup allocators
    56	   *
    57	   *  This is precisely the allocator defined in the C++03 Standard.
    58	   */
    59	  template<typename _Alloc>
    60	    class debug_allocator
    61	    {
    62	      template<typename> friend class debug_allocator;
    63	
    64	      typedef __alloc_traits<_Alloc> _Traits;
    65	
    66	    public:
    67	      typedef typename _Traits::size_type       	size_type;
    68	      typedef typename _Traits::difference_type	difference_type;
    69	      typedef typename _Traits::pointer       	pointer;
    70	      typedef typename _Traits::const_pointer    const_pointer;
    71	      typedef typename _Traits::reference       	reference;
    72	      typedef typename _Traits::const_reference  const_reference;
    73	      typedef typename _Traits::value_type       value_type;
    74	
    75	      template<typename _Up>
    76		class rebind
    77		{
    78		  typedef typename _Traits::template rebind<_Up>::other __other;
    79	
    80		public:
    81		  typedef debug_allocator<__other> other;
    82		};
    83	
    84	    private:
    85	      // _M_extra is the number of objects that correspond to the
    86	      // extra space where debug information is stored.
    87	      size_type 		_M_extra;
    88	      
    89	      _Alloc			_M_allocator;
    90	
    91	      template<typename _Alloc2,
    92		       typename = typename __alloc_traits<_Alloc2>::template
    93				   rebind<value_type>::other>
    94		struct __convertible
    95		{ };
    96	
    97	      template<typename _Alloc2>
    98		struct __convertible<_Alloc2, _Alloc>
    99		{
   100		  typedef void* __type;
   101		};
   102	
   103	      size_type _S_extra()
   104	      {
   105		const std::size_t __obj_size = sizeof(value_type);
   106		return (sizeof(size_type) + __obj_size - 1) / __obj_size; 
   107	      }
   108	
   109	    public:
   110	      debug_allocator() : _M_extra(_S_extra()) { }
   111	
   112	      template<typename _Alloc2>
   113		debug_allocator(const debug_allocator<_Alloc2>& __a2,
   114				typename __convertible<_Alloc2>::__type = 0)
   115		: _M_extra(_S_extra()), _M_allocator(__a2._M_allocator)  { }
   116	
   117	      debug_allocator(const _Alloc& __a)
   118	      : _M_extra(_S_extra()), _M_allocator(__a)  { }
   119	
   120	      _GLIBCXX_NODISCARD pointer
   121	      allocate(size_type __n)
   122	      {
   123	        pointer __res = _M_allocator.allocate(__n + _M_extra);      
   124		size_type* __ps = reinterpret_cast<size_type*>(__res);
   125		*__ps = __n;
   126	        return __res + _M_extra;
   127	      }
   128	
   129	      _GLIBCXX_NODISCARD pointer
   130	      allocate(size_type __n, const void* __hint)
   131	      {
   132	        pointer __res = _M_allocator.allocate(__n + _M_extra, __hint);
   133		size_type* __ps = reinterpret_cast<size_type*>(__res);
   134		*__ps = __n;
   135	        return __res + _M_extra;
   136	      }
   137	
   138	      void
   139	      deallocate(pointer __p, size_type __n)
   140	      {
   141		using std::__throw_runtime_error;
   142		if (__p)
   143		  {
   144		    pointer __real_p = __p - _M_extra;
   145		    if (*reinterpret_cast<size_type*>(__real_p) != __n)
   146		      __throw_runtime_error("debug_allocator::deallocate wrong size");
   147		    _M_allocator.deallocate(__real_p, __n + _M_extra);
   148		  }
   149		else
   150		  __throw_runtime_error("debug_allocator::deallocate null pointer");
   151	      }
   152	
   153	      void
   154	      construct(pointer __p, const value_type& __val)
   155	      { _Traits::construct(_M_allocator, __p, __val); }
   156	
   157	#if __cplusplus >= 201103L
   158	      template<typename _Tp, typename... _Args>
   159		void
   160		construct(_Tp* __p, _Args&&... __args)
   161		{
   162		  _Traits::construct(_M_allocator, __p,
   163				     std::forward<_Args>(__args)...);
   164		}
   165	#endif
   166	
   167	      template<typename _Tp>
   168		void
   169		destroy(_Tp* __p)
   170		{ _Traits::destroy(_M_allocator, __p); }
   171	
   172	      size_type
   173	      max_size() const throw()
   174	      { return _Traits::max_size(_M_allocator) - _M_extra; }
   175	
   176	      template<typename _Alloc2>
   177		friend bool
   178		operator==(const debug_allocator& __lhs,
   179			   const debug_allocator<_Alloc2>& __rhs) _GLIBCXX_NOTHROW
   180		{ return __lhs._M_allocator == debug_allocator(__rhs)._M_allocator; }
   181	
   182	#if __cpp_impl_three_way_comparison < 201907L
   183	      template<typename _Alloc2>
   184		friend bool
   185		operator!=(const debug_allocator& __lhs,
   186			   const debug_allocator<_Alloc2>& __rhs) _GLIBCXX_NOTHROW
   187		{ return !(__lhs == __rhs); }
   188	#endif
   189	    };
   190	
   191	_GLIBCXX_END_NAMESPACE_VERSION
   192	} // namespace
   193	
   194	#endif