1 // Debugging iterator implementation (out of line) -*- C++ -*- 2 3 // Copyright (C) 2003-2019 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_iterator.tcc 26 * This file is a GNU debug extension to the Standard C++ Library. 27 */ 28 29 #ifndef _GLIBCXX_DEBUG_SAFE_ITERATOR_TCC 30 #define _GLIBCXX_DEBUG_SAFE_ITERATOR_TCC 1 31 32 namespace __gnu_debug 33 { 34 template<typename _Iterator, typename _Sequence, typename _Category> 35 typename _Distance_traits<_Iterator>::__type 36 _Safe_iterator<_Iterator, _Sequence, _Category>:: 37 _M_get_distance_from_begin() const 38 { 39 typedef _Sequence_traits<_Sequence> _SeqTraits; 40 41 // No need to consider before_begin as this function is only used in 42 // _M_can_advance which won't be used for forward_list iterators. 43 if (_M_is_begin()) 44 return std::make_pair(0, __dp_exact); 45 46 if (_M_is_end()) 47 return _SeqTraits::_S_size(*_M_get_sequence()); 48 49 typename _Distance_traits<_Iterator>::__type __res 50 = __get_distance(_M_get_sequence()->_M_base().begin(), base()); 51 52 if (__res.second == __dp_equality) 53 return std::make_pair(1, __dp_sign); 54 55 return __res; 56 } 57 58 template<typename _Iterator, typename _Sequence, typename _Category> 59 typename _Distance_traits<_Iterator>::__type 60 _Safe_iterator<_Iterator, _Sequence, _Category>:: 61 _M_get_distance_to_end() const 62 { 63 typedef _Sequence_traits<_Sequence> _SeqTraits; 64 65 // No need to consider before_begin as this function is only used in 66 // _M_can_advance which won't be used for forward_list iterators. 67 if (_M_is_begin()) 68 return _SeqTraits::_S_size(*_M_get_sequence()); 69 70 if (_M_is_end()) 71 return std::make_pair(0, __dp_exact); 72 73 typename _Distance_traits<_Iterator>::__type __res 74 = __get_distance(base(), _M_get_sequence()->_M_base().end()); 75 76 if (__res.second == __dp_equality) 77 return std::make_pair(1, __dp_sign); 78 79 return __res; 80 } 81 82 template<typename _Iterator, typename _Sequence, typename _Category> 83 bool 84 _Safe_iterator<_Iterator, _Sequence, _Category>:: 85 _M_can_advance(difference_type __n) const 86 { 87 if (this->_M_singular()) 88 return false; 89 90 if (__n == 0) 91 return true; 92 93 if (__n < 0) 94 { 95 std::pair<difference_type, _Distance_precision> __dist = 96 _M_get_distance_from_begin(); 97 bool __ok = ((__dist.second == __dp_exact && __dist.first >= -__n) 98 || (__dist.second != __dp_exact && __dist.first > 0)); 99 return __ok; 100 } 101 else 102 { 103 std::pair<difference_type, _Distance_precision> __dist = 104 _M_get_distance_to_end(); 105 bool __ok = ((__dist.second == __dp_exact && __dist.first >= __n) 106 || (__dist.second != __dp_exact && __dist.first > 0)); 107 return __ok; 108 } 109 } 110 111 template<typename _Iterator, typename _Sequence, typename _Category> 112 typename _Distance_traits<_Iterator>::__type 113 _Safe_iterator<_Iterator, _Sequence, _Category>:: 114 _M_get_distance_to(const _Safe_iterator& __rhs) const 115 { 116 typedef typename _Distance_traits<_Iterator>::__type _Diff; 117 typedef _Sequence_traits<_Sequence> _SeqTraits; 118 119 if (this->base() == __rhs.base()) 120 return std::make_pair(0, __dp_exact); 121 122 if (this->_M_is_before_begin()) 123 { 124 if (__rhs._M_is_begin()) 125 return std::make_pair(1, __dp_exact); 126 127 return std::make_pair(1, __dp_sign); 128 } 129 130 if (this->_M_is_begin()) 131 { 132 if (__rhs._M_is_before_begin()) 133 return std::make_pair(-1, __dp_exact); 134 135 if (__rhs._M_is_end()) 136 return _SeqTraits::_S_size(*this->_M_get_sequence()); 137 138 return std::make_pair(1, __dp_sign); 139 } 140 141 if (this->_M_is_end()) 142 { 143 if (__rhs._M_is_before_begin()) 144 return std::make_pair(-1, __dp_exact); 145 146 if (__rhs._M_is_begin()) 147 { 148 _Diff __diff = _SeqTraits::_S_size(*this->_M_get_sequence()); 149 return std::make_pair(-__diff.first, __diff.second); 150 } 151 152 return std::make_pair(-1, __dp_sign); 153 } 154 155 if (__rhs._M_is_before_begin() || __rhs._M_is_begin()) 156 return std::make_pair(-1, __dp_sign); 157 158 if (__rhs._M_is_end()) 159 return std::make_pair(1, __dp_sign); 160 161 return std::make_pair(1, __dp_equality); 162 } 163 164 template<typename _Iterator, typename _Sequence, typename _Category> 165 bool 166 _Safe_iterator<_Iterator, _Sequence, _Category>:: 167 _M_valid_range(const _Safe_iterator& __rhs, 168 std::pair<difference_type, _Distance_precision>& __dist, 169 bool __check_dereferenceable) const 170 { 171 if (!_M_can_compare(__rhs)) 172 return false; 173 174 /* Determine iterators order */ 175 __dist = _M_get_distance_to(__rhs); 176 switch (__dist.second) 177 { 178 case __dp_equality: 179 if (__dist.first == 0) 180 return true; 181 break; 182 183 case __dp_sign: 184 case __dp_exact: 185 // If range is not empty first iterator must be dereferenceable. 186 if (__dist.first > 0) 187 return !__check_dereferenceable || _M_dereferenceable(); 188 return __dist.first == 0; 189 } 190 191 // Assume that this is a valid range; we can't check anything else. 192 return true; 193 } 194 195 template<typename _Iterator, typename _Sequence> 196 bool 197 _Safe_iterator<_Iterator, _Sequence, std::random_access_iterator_tag>:: 198 _M_valid_range(const _Safe_iterator& __rhs, 199 std::pair<difference_type, 200 _Distance_precision>& __dist) const 201 { 202 if (!this->_M_can_compare(__rhs)) 203 return false; 204 205 /* Determine iterators order */ 206 __dist = std::make_pair(__rhs.base() - this->base(), __dp_exact); 207 208 // If range is not empty first iterator must be dereferenceable. 209 if (__dist.first > 0) 210 return this->_M_dereferenceable(); 211 return __dist.first == 0; 212 } 213 } // namespace __gnu_debug 214 215 #endif 216