1 // Safe sequence implementation -*- C++ -*- 2 3 // Copyright (C) 2003-2018 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_sequence.h 26 * This file is a GNU debug extension to the Standard C++ Library. 27 */ 28 29 #ifndef _GLIBCXX_DEBUG_SAFE_SEQUENCE_H 30 #define _GLIBCXX_DEBUG_SAFE_SEQUENCE_H 1 31 32 #include <debug/assertions.h> 33 #include <debug/macros.h> 34 #include <debug/functions.h> 35 #include <debug/safe_base.h> 36 37 namespace __gnu_debug 38 { 39 /** A simple function object that returns true if the passed-in 40 * value is not equal to the stored value. It saves typing over 41 * using both bind1st and not_equal. 42 */ 43 template<typename _Type> 44 class _Not_equal_to 45 { 46 _Type __value; 47 48 public: 49 explicit _Not_equal_to(const _Type& __v) : __value(__v) { } 50 51 bool 52 operator()(const _Type& __x) const 53 { return __value != __x; } 54 }; 55 56 /** A simple function object that returns true if the passed-in 57 * value is equal to the stored value. */ 58 template <typename _Type> 59 class _Equal_to 60 { 61 _Type __value; 62 63 public: 64 explicit _Equal_to(const _Type& __v) : __value(__v) { } 65 66 bool 67 operator()(const _Type& __x) const 68 { return __value == __x; } 69 }; 70 71 /** A function object that returns true when the given random access 72 iterator is at least @c n steps away from the given iterator. */ 73 template<typename _Iterator> 74 class _After_nth_from 75 { 76 typedef typename std::iterator_traits<_Iterator>::difference_type 77 difference_type; 78 79 _Iterator _M_base; 80 difference_type _M_n; 81 82 public: 83 _After_nth_from(const difference_type& __n, const _Iterator& __base) 84 : _M_base(__base), _M_n(__n) { } 85 86 bool 87 operator()(const _Iterator& __x) const 88 { return __x - _M_base >= _M_n; } 89 }; 90 91 /** 92 * @brief Base class for constructing a @a safe sequence type that 93 * tracks iterators that reference it. 94 * 95 * The class template %_Safe_sequence simplifies the construction of 96 * @a safe sequences that track the iterators that reference the 97 * sequence, so that the iterators are notified of changes in the 98 * sequence that may affect their operation, e.g., if the container 99 * invalidates its iterators or is destructed. This class template 100 * may only be used by deriving from it and passing the name of the 101 * derived class as its template parameter via the curiously 102 * recurring template pattern. The derived class must have @c 103 * iterator and @c const_iterator types that are instantiations of 104 * class template _Safe_iterator for this sequence. Iterators will 105 * then be tracked automatically. 106 */ 107 template<typename _Sequence> 108 class _Safe_sequence : public _Safe_sequence_base 109 { 110 public: 111 /** Invalidates all iterators @c x that reference this sequence, 112 are not singular, and for which @c __pred(x) returns @c 113 true. @c __pred will be invoked with the normal iterators nested 114 in the safe ones. */ 115 template<typename _Predicate> 116 void 117 _M_invalidate_if(_Predicate __pred); 118 119 /** Transfers all iterators @c x that reference @c from sequence, 120 are not singular, and for which @c __pred(x) returns @c 121 true. @c __pred will be invoked with the normal iterators nested 122 in the safe ones. */ 123 template<typename _Predicate> 124 void 125 _M_transfer_from_if(_Safe_sequence& __from, _Predicate __pred); 126 }; 127 128 /// Like _Safe_sequence but with a special _M_invalidate_all implementation 129 /// not invalidating past-the-end iterators. Used by node based sequence. 130 template<typename _Sequence> 131 class _Safe_node_sequence 132 : public _Safe_sequence<_Sequence> 133 { 134 protected: 135 void 136 _M_invalidate_all() 137 { 138 typedef typename _Sequence::const_iterator _Const_iterator; 139 typedef typename _Const_iterator::iterator_type _Base_const_iterator; 140 typedef __gnu_debug::_Not_equal_to<_Base_const_iterator> _Not_equal; 141 const _Sequence& __seq = *static_cast<_Sequence*>(this); 142 this->_M_invalidate_if(_Not_equal(__seq._M_base().end())); 143 } 144 }; 145 146 } // namespace __gnu_debug 147 148 #include <debug/safe_sequence.tcc> 149 150 #endif 151