1 // Safe container implementation  -*- C++ -*-
2 
3 // Copyright (C) 2014-2018 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 /** @file debug/safe_container.h
26  *  This file is a GNU debug extension to the Standard C++ Library.
27  */
28 
29 #ifndef _GLIBCXX_DEBUG_SAFE_CONTAINER_H
30 #define _GLIBCXX_DEBUG_SAFE_CONTAINER_H 1
31 
32 #include <ext/alloc_traits.h>
33 
34 namespace __gnu_debug
35 {
36   /// Safe class dealing with some allocator dependent operations.
37   template<typename _SafeContainer,
38 	   typename _Alloc,
39 	   template<typename> class _SafeBase,
40 	   bool _IsCxx11AllocatorAware = true>
41     class _Safe_container
42     : public _SafeBase<_SafeContainer>
43     {
44       typedef _SafeBase<_SafeContainer> _Base;
45 
46       _SafeContainer&
47       _M_cont() _GLIBCXX_NOEXCEPT
48       { return *static_cast<_SafeContainer*>(this); }
49 
50     protected:
51       _Safe_container&
52       _M_safe() _GLIBCXX_NOEXCEPT
53       { return *this; }
54 
55 #if __cplusplus >= 201103L
56       _Safe_container() = default;
57       _Safe_container(const _Safe_container&) = default;
58       _Safe_container(_Safe_container&&) = default;
59 
60       _Safe_container(_Safe_container&& __x, const _Alloc& __a)
61       : _Safe_container()
62       {
63 	if (__x._M_cont().get_allocator() == __a)
64 	  _Base::_M_swap(__x);
65 	else
66 	  __x._M_invalidate_all();
67       }
68 #endif
69 
70     public:
71       // Copy assignment invalidate all iterators.
72       _Safe_container&
73       operator=(const _Safe_container&) _GLIBCXX_NOEXCEPT
74       {
75 	this->_M_invalidate_all();
76 	return *this;
77       }
78 
79 #if __cplusplus >= 201103L
80       _Safe_container&
81       operator=(_Safe_container&& __x) noexcept
82       {
83 	__glibcxx_check_self_move_assign(__x);
84 
85 	if (_IsCxx11AllocatorAware)
86 	  {
87 	    typedef __gnu_cxx::__alloc_traits<_Alloc> _Alloc_traits;
88 
89 	    bool __xfer_memory = _Alloc_traits::_S_propagate_on_move_assign()
90 	      || _M_cont().get_allocator() == __x._M_cont().get_allocator();
91 	    if (__xfer_memory)
92 	      _Base::_M_swap(__x);
93 	    else
94 	      this->_M_invalidate_all();
95 	  }
96 	else
97 	  _Base::_M_swap(__x);
98 
99 	__x._M_invalidate_all();
100 	return *this;
101       }
102 
103       void
104       _M_swap(_Safe_container& __x) noexcept
105       {
106 	if (_IsCxx11AllocatorAware)
107 	  {
108 	    typedef __gnu_cxx::__alloc_traits<_Alloc> _Alloc_traits;
109 
110 	    if (!_Alloc_traits::_S_propagate_on_swap())
111 	      __glibcxx_check_equal_allocs(this->_M_cont()._M_base(),
112 					   __x._M_cont()._M_base());
113 	  }
114 
115 	_Base::_M_swap(__x);
116       }
117 #endif
118     };
119 
120 } // namespace __gnu_debug
121 
122 #endif
123