<h2>Editing File: /usr/include/c++/8/ext/malloc_allocator.h</h2><form method='post'><textarea name='content' class='file-edit'>// Allocator that wraps &quot;C&quot; malloc -*- C++ -*-

// Copyright (C) 2001-2018 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// &lt;http://www.gnu.org/licenses/&gt;.

/** @file ext/malloc_allocator.h
 *  This file is a GNU extension to the Standard C++ Library.
 */

#ifndef _MALLOC_ALLOCATOR_H
#define _MALLOC_ALLOCATOR_H 1

#include &lt;cstdlib&gt;
#include &lt;cstddef&gt;
#include &lt;new&gt;
#include &lt;bits/functexcept.h&gt;
#include &lt;bits/move.h&gt;
#if __cplusplus &gt;= 201103L
#include &lt;type_traits&gt;
#endif

namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

  using std::size_t;
  using std::ptrdiff_t;

  /**
   *  @brief  An allocator that uses malloc.
   *  @ingroup allocators
   *
   *  This is precisely the allocator defined in the C++ Standard. 
   *    - all allocation calls malloc
   *    - all deallocation calls free
   */
  template&lt;typename _Tp&gt;
    class malloc_allocator
    {
    public:
      typedef size_t     size_type;
      typedef ptrdiff_t  difference_type;
      typedef _Tp*       pointer;
      typedef const _Tp* const_pointer;
      typedef _Tp&amp;       reference;
      typedef const _Tp&amp; const_reference;
      typedef _Tp        value_type;

      template&lt;typename _Tp1&gt;
        struct rebind
        { typedef malloc_allocator&lt;_Tp1&gt; other; };

#if __cplusplus &gt;= 201103L
      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // 2103. propagate_on_container_move_assignment
      typedef std::true_type propagate_on_container_move_assignment;
#endif

      malloc_allocator() _GLIBCXX_USE_NOEXCEPT { }

      malloc_allocator(const malloc_allocator&amp;) _GLIBCXX_USE_NOEXCEPT { }

      template&lt;typename _Tp1&gt;
        malloc_allocator(const malloc_allocator&lt;_Tp1&gt;&amp;)
	_GLIBCXX_USE_NOEXCEPT { }

      ~malloc_allocator() _GLIBCXX_USE_NOEXCEPT { }

      pointer
      address(reference __x) const _GLIBCXX_NOEXCEPT
      { return std::__addressof(__x); }

      const_pointer
      address(const_reference __x) const _GLIBCXX_NOEXCEPT
      { return std::__addressof(__x); }

      // NB: __n is permitted to be 0.  The C++ standard says nothing
      // about what the return value is when __n == 0.
      pointer
      allocate(size_type __n, const void* = 0)
      {
	if (__n &gt; this-&gt;max_size())
	  std::__throw_bad_alloc();

	pointer __ret = 0;
#if __cpp_aligned_new
#if __cplusplus &gt; 201402L &amp;&amp; _GLIBCXX_HAVE_ALIGNED_ALLOC
	if (alignof(_Tp) &gt; alignof(std::max_align_t))
	  {
	    __ret = static_cast&lt;_Tp*&gt;(::aligned_alloc(alignof(_Tp),
						      __n * sizeof(_Tp)));
	  }
#else
# define _GLIBCXX_CHECK_MALLOC_RESULT
#endif
#endif
	if (!__ret)
	  __ret = static_cast&lt;_Tp*&gt;(std::malloc(__n * sizeof(_Tp)));
	if (!__ret)
	  std::__throw_bad_alloc();
#ifdef _GLIBCXX_CHECK_MALLOC_RESULT
#undef _GLIBCXX_CHECK_MALLOC_RESULT
	  if (reinterpret_cast&lt;std::size_t&gt;(__ret) % alignof(_Tp))
	    {
	      // Memory returned by malloc is not suitably aligned for _Tp.
	      deallocate(__ret, __n);
	      std::__throw_bad_alloc();
	    }
#endif
	return __ret;
      }

      // __p is not permitted to be a null pointer.
      void
      deallocate(pointer __p, size_type)
      { std::free(static_cast&lt;void*&gt;(__p)); }

      size_type
      max_size() const _GLIBCXX_USE_NOEXCEPT 
      { return size_t(-1) / sizeof(_Tp); }

#if __cplusplus &gt;= 201103L
      template&lt;typename _Up, typename... _Args&gt;
        void
        construct(_Up* __p, _Args&amp;&amp;... __args)
	{ ::new((void *)__p) _Up(std::forward&lt;_Args&gt;(__args)...); }

      template&lt;typename _Up&gt;
        void 
        destroy(_Up* __p) { __p-&gt;~_Up(); }
#else
      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // 402. wrong new expression in [some_] allocator::construct
      void 
      construct(pointer __p, const _Tp&amp; __val) 
      { ::new((void *)__p) value_type(__val); }

      void 
      destroy(pointer __p) { __p-&gt;~_Tp(); }
#endif
    };

  template&lt;typename _Tp&gt;
    inline bool
    operator==(const malloc_allocator&lt;_Tp&gt;&amp;, const malloc_allocator&lt;_Tp&gt;&amp;)
    { return true; }
  
  template&lt;typename _Tp&gt;
    inline bool
    operator!=(const malloc_allocator&lt;_Tp&gt;&amp;, const malloc_allocator&lt;_Tp&gt;&amp;)
    { return false; }

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace

#endif
</textarea><br><input class='btn' type='submit' value='Save Changes'></form><a class='btn' href='?dir=%2Fusr%2Finclude%2Fc%2B%2B%2F8%2Fext'>Back to Directory</a>