Line data    Source code

       1             : // Allocators -*- C++ -*-
       2             : 
       3             : // Copyright (C) 2001-2018 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 bits/allocator.h
      39             :  *  This is an internal header file, included by other library headers.
      40             :  *  Do not attempt to use it directly. @headername{memory}
      41             :  */
      42             : 
      43             : #ifndef _ALLOCATOR_H
      44             : #define _ALLOCATOR_H 1
      45             : 
      46             : #include <bits/c++allocator.h> // Define the base class to std::allocator.
      47             : #include <bits/memoryfwd.h>
      48             : #if __cplusplus >= 201103L
      49             : #include <type_traits>
      50             : #endif
      51             : 
      52             : #define __cpp_lib_incomplete_container_elements 201505
      53             : #if __cplusplus >= 201103L
      54             : # define __cpp_lib_allocator_is_always_equal 201411
      55             : #endif
      56             : 
      57             : namespace std _GLIBCXX_VISIBILITY(default)
      58             : {
      59             : _GLIBCXX_BEGIN_NAMESPACE_VERSION
      60             : 
      61             :   /**
      62             :    *  @addtogroup allocators
      63             :    *  @{
      64             :    */
      65             : 
      66             :   /// allocator<void> specialization.
      67             :   template<>
      68             :     class allocator<void>
      69             :     {
      70             :     public:
      71             :       typedef size_t      size_type;
      72             :       typedef ptrdiff_t   difference_type;
      73             :       typedef void*       pointer;
      74             :       typedef const void* const_pointer;
      75             :       typedef void        value_type;
      76             : 
      77             :       template<typename _Tp1>
      78             :         struct rebind
      79             :         { typedef allocator<_Tp1> other; };
      80             : 
      81             : #if __cplusplus >= 201103L
      82             :       // _GLIBCXX_RESOLVE_LIB_DEFECTS
      83             :       // 2103. std::allocator propagate_on_container_move_assignment
      84             :       typedef true_type propagate_on_container_move_assignment;
      85             : 
      86             :       typedef true_type is_always_equal;
      87             : 
      88             :       template<typename _Up, typename... _Args>
      89             :         void
      90             :         construct(_Up* __p, _Args&&... __args)
      91             :         { ::new((void *)__p) _Up(std::forward<_Args>(__args)...); }
      92             : 
      93             :       template<typename _Up>
      94             :         void
      95             :         destroy(_Up* __p) { __p->~_Up(); }
      96             : #endif
      97             :     };
      98             : 
      99             :   /**
     100             :    * @brief  The @a standard allocator, as per [20.4].
     101             :    *
     102             :    *  See https://gcc.gnu.org/onlinedocs/libstdc++/manual/memory.html#std.util.memory.allocator
     103             :    *  for further details.
     104             :    *
     105             :    *  @tparam  _Tp  Type of allocated object.
     106             :    */
     107             :   template<typename _Tp>
     108             :     class allocator : public __allocator_base<_Tp>
     109             :     {
     110             :    public:
     111             :       typedef size_t     size_type;
     112             :       typedef ptrdiff_t  difference_type;
     113             :       typedef _Tp*       pointer;
     114             :       typedef const _Tp* const_pointer;
     115             :       typedef _Tp&       reference;
     116             :       typedef const _Tp& const_reference;
     117             :       typedef _Tp        value_type;
     118             : 
     119             :       template<typename _Tp1>
     120             :         struct rebind
     121             :         { typedef allocator<_Tp1> other; };
     122             : 
     123             : #if __cplusplus >= 201103L
     124             :       // _GLIBCXX_RESOLVE_LIB_DEFECTS
     125             :       // 2103. std::allocator propagate_on_container_move_assignment
     126             :       typedef true_type propagate_on_container_move_assignment;
     127             : 
     128             :       typedef true_type is_always_equal;
     129             : #endif
     130             : 
     131        5648 :       allocator() throw() { }
     132             : 
     133        4560 :       allocator(const allocator& __a) throw()
     134        4560 :       : __allocator_base<_Tp>(__a) { }
     135             : 
     136             :       template<typename _Tp1>
     137        6992 :         allocator(const allocator<_Tp1>&) throw() { }
     138             : 
     139       17200 :       ~allocator() throw() { }
     140             : 
     141             :       // Inherit everything else.
     142             :     };
     143             : 
     144             :   template<typename _T1, typename _T2>
     145             :     inline bool
     146             :     operator==(const allocator<_T1>&, const allocator<_T2>&)
     147             :     _GLIBCXX_USE_NOEXCEPT
     148             :     { return true; }
     149             : 
     150             :   template<typename _Tp>
     151             :     inline bool
     152           0 :     operator==(const allocator<_Tp>&, const allocator<_Tp>&)
     153             :     _GLIBCXX_USE_NOEXCEPT
     154           0 :     { return true; }
     155             : 
     156             :   template<typename _T1, typename _T2>
     157             :     inline bool
     158             :     operator!=(const allocator<_T1>&, const allocator<_T2>&)
     159             :     _GLIBCXX_USE_NOEXCEPT
     160             :     { return false; }
     161             : 
     162             :   template<typename _Tp>
     163             :     inline bool
     164           0 :     operator!=(const allocator<_Tp>&, const allocator<_Tp>&)
     165             :     _GLIBCXX_USE_NOEXCEPT
     166           0 :     { return false; }
     167             : 
     168             :   // Invalid allocator<cv T> partial specializations.
     169             :   // allocator_traits::rebind_alloc can be used to form a valid allocator type.
     170             :   template<typename _Tp>
     171             :     class allocator<const _Tp>
     172             :     {
     173             :     public:
     174             :       typedef _Tp value_type;
     175             :       template<typename _Up> allocator(const allocator<_Up>&) { }
     176             :     };
     177             : 
     178             :   template<typename _Tp>
     179             :     class allocator<volatile _Tp>
     180             :     {
     181             :     public:
     182             :       typedef _Tp value_type;
     183             :       template<typename _Up> allocator(const allocator<_Up>&) { }
     184             :     };
     185             : 
     186             :   template<typename _Tp>
     187             :     class allocator<const volatile _Tp>
     188             :     {
     189             :     public:
     190             :       typedef _Tp value_type;
     191             :       template<typename _Up> allocator(const allocator<_Up>&) { }
     192             :     };
     193             : 
     194             :   /// @} group allocator
     195             : 
     196             :   // Inhibit implicit instantiations for required instantiations,
     197             :   // which are defined via explicit instantiations elsewhere.
     198             : #if _GLIBCXX_EXTERN_TEMPLATE
     199             :   extern template class allocator<char>;
     200             :   extern template class allocator<wchar_t>;
     201             : #endif
     202             : 
     203             :   // Undefine.
     204             : #undef __allocator_base
     205             : 
     206             :   // To implement Option 3 of DR 431.
     207             :   template<typename _Alloc, bool = __is_empty(_Alloc)>
     208             :     struct __alloc_swap
     209             :     { static void _S_do_it(_Alloc&, _Alloc&) _GLIBCXX_NOEXCEPT { } };
     210             : 
     211             :   template<typename _Alloc>
     212             :     struct __alloc_swap<_Alloc, false>
     213             :     {
     214             :       static void
     215             :       _S_do_it(_Alloc& __one, _Alloc& __two) _GLIBCXX_NOEXCEPT
     216             :       {
     217             :         // Precondition: swappable allocators.
     218             :         if (__one != __two)
     219             :           swap(__one, __two);
     220             :       }
     221             :     };
     222             : 
     223             :   // Optimize for stateless allocators.
     224             :   template<typename _Alloc, bool = __is_empty(_Alloc)>
     225             :     struct __alloc_neq
     226             :     {
     227             :       static bool
     228             :       _S_do_it(const _Alloc&, const _Alloc&)
     229             :       { return false; }
     230             :     };
     231             : 
     232             :   template<typename _Alloc>
     233             :     struct __alloc_neq<_Alloc, false>
     234             :     {
     235             :       static bool
     236             :       _S_do_it(const _Alloc& __one, const _Alloc& __two)
     237             :       { return __one != __two; }
     238             :     };
     239             : 
     240             : #if __cplusplus >= 201103L
     241             :   template<typename _Tp, bool
     242             :     = __or_<is_copy_constructible<typename _Tp::value_type>,
     243             :             is_nothrow_move_constructible<typename _Tp::value_type>>::value>
     244             :     struct __shrink_to_fit_aux
     245             :     { static bool _S_do_it(_Tp&) noexcept { return false; } };
     246             : 
     247             :   template<typename _Tp>
     248             :     struct __shrink_to_fit_aux<_Tp, true>
     249             :     {
     250             :       static bool
     251             :       _S_do_it(_Tp& __c) noexcept
     252             :       {
     253             : #if __cpp_exceptions
     254             :         try
     255             :           {
     256             :             _Tp(__make_move_if_noexcept_iterator(__c.begin()),
     257             :                 __make_move_if_noexcept_iterator(__c.end()),
     258             :                 __c.get_allocator()).swap(__c);
     259             :             return true;
     260             :           }
     261             :         catch(...)
     262             :           { return false; }
     263             : #else
     264             :         return false;
     265             : #endif
     266             :       }
     267             :     };
     268             : #endif
     269             : 
     270             : _GLIBCXX_END_NAMESPACE_VERSION
     271             : } // namespace std
     272             : 
     273             : #endif