Edit File: safe_iterator.h
// Safe iterator implementation -*- C++ -*- // Copyright (C) 2003-2018 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 // <http://www.gnu.org/licenses/>. /** @file debug/safe_iterator.h * This file is a GNU debug extension to the Standard C++ Library. */ #ifndef _GLIBCXX_DEBUG_SAFE_ITERATOR_H #define _GLIBCXX_DEBUG_SAFE_ITERATOR_H 1 #include <debug/assertions.h> #include <debug/macros.h> #include <debug/functions.h> #include <debug/safe_base.h> #include <bits/stl_pair.h> #include <ext/type_traits.h> namespace __gnu_debug { /** Helper struct to deal with sequence offering a before_begin * iterator. **/ template<typename _Sequence> struct _BeforeBeginHelper { template<typename _Iterator> static bool _S_Is(const _Safe_iterator<_Iterator, _Sequence>&) { return false; } template<typename _Iterator> static bool _S_Is_Beginnest(const _Safe_iterator<_Iterator, _Sequence>& __it) { return __it.base() == __it._M_get_sequence()->_M_base().begin(); } }; /** Sequence traits giving the size of a container if possible. */ template<typename _Sequence> struct _Sequence_traits { typedef _Distance_traits<typename _Sequence::iterator> _DistTraits; static typename _DistTraits::__type _S_size(const _Sequence& __seq) { return std::make_pair(__seq.size(), __dp_exact); } }; /** \brief Safe iterator wrapper. * * The class template %_Safe_iterator is a wrapper around an * iterator that tracks the iterator's movement among sequences and * checks that operations performed on the "safe" iterator are * legal. In additional to the basic iterator operations (which are * validated, and then passed to the underlying iterator), * %_Safe_iterator has member functions for iterator invalidation, * attaching/detaching the iterator from sequences, and querying * the iterator's state. * * Note that _Iterator must be the first base class so that it gets * initialized before the iterator is being attached to the container's list * of iterators and it is being detached before _Iterator get * destroyed. Otherwise it would result in a data race. */ template<typename _Iterator, typename _Sequence> class _Safe_iterator : private _Iterator, public _Safe_iterator_base { typedef _Iterator _Iter_base; typedef _Safe_iterator_base _Safe_base; typedef typename _Sequence::const_iterator _Const_iterator; /// Determine if this is a constant iterator. bool _M_constant() const { return std::__are_same<_Const_iterator, _Safe_iterator>::__value; } typedef std::iterator_traits<_Iterator> _Traits; struct _Attach_single { }; _Safe_iterator(const _Iterator& __i, _Safe_sequence_base* __seq, _Attach_single) _GLIBCXX_NOEXCEPT : _Iter_base(__i) { _M_attach_single(__seq); } public: typedef _Iterator iterator_type; typedef typename _Traits::iterator_category iterator_category; typedef typename _Traits::value_type value_type; typedef typename _Traits::difference_type difference_type; typedef typename _Traits::reference reference; typedef typename _Traits::pointer pointer; /// @post the iterator is singular and unattached _Safe_iterator() _GLIBCXX_NOEXCEPT : _Iter_base() { } /** * @brief Safe iterator construction from an unsafe iterator and * its sequence. * * @pre @p seq is not NULL * @post this is not singular */ _Safe_iterator(const _Iterator& __i, const _Safe_sequence_base* __seq) _GLIBCXX_NOEXCEPT : _Iter_base(__i), _Safe_base(__seq, _M_constant()) { _GLIBCXX_DEBUG_VERIFY(!this->_M_singular(), _M_message(__msg_init_singular) ._M_iterator(*this, "this")); } /** * @brief Copy construction. */ _Safe_iterator(const _Safe_iterator& __x) _GLIBCXX_NOEXCEPT : _Iter_base(__x.base()) { // _GLIBCXX_RESOLVE_LIB_DEFECTS // DR 408. Is vector<reverse_iterator<char*> > forbidden? _GLIBCXX_DEBUG_VERIFY(!__x._M_singular() || __x.base() == _Iterator(), _M_message(__msg_init_copy_singular) ._M_iterator(*this, "this") ._M_iterator(__x, "other")); _M_attach(__x._M_sequence); } #if __cplusplus >= 201103L /** * @brief Move construction. * @post __x is singular and unattached */ _Safe_iterator(_Safe_iterator&& __x) noexcept : _Iter_base() { _GLIBCXX_DEBUG_VERIFY(!__x._M_singular() || __x.base() == _Iterator(), _M_message(__msg_init_copy_singular) ._M_iterator(*this, "this") ._M_iterator(__x, "other")); _Safe_sequence_base* __seq = __x._M_sequence; __x._M_detach(); std::swap(base(), __x.base()); _M_attach(__seq); } #endif /** * @brief Converting constructor from a mutable iterator to a * constant iterator. */ template<typename _MutableIterator> _Safe_iterator( const _Safe_iterator<_MutableIterator, typename __gnu_cxx::__enable_if<(std::__are_same<_MutableIterator, typename _Sequence::iterator::iterator_type>::__value), _Sequence>::__type>& __x) _GLIBCXX_NOEXCEPT : _Iter_base(__x.base()) { // _GLIBCXX_RESOLVE_LIB_DEFECTS // DR 408. Is vector<reverse_iterator<char*> > forbidden? _GLIBCXX_DEBUG_VERIFY(!__x._M_singular() || __x.base() == _Iterator(), _M_message(__msg_init_const_singular) ._M_iterator(*this, "this") ._M_iterator(__x, "other")); _M_attach(__x._M_sequence); } /** * @brief Copy assignment. */ _Safe_iterator& operator=(const _Safe_iterator& __x) _GLIBCXX_NOEXCEPT { // _GLIBCXX_RESOLVE_LIB_DEFECTS // DR 408. Is vector<reverse_iterator<char*> > forbidden? _GLIBCXX_DEBUG_VERIFY(!__x._M_singular() || __x.base() == _Iterator(), _M_message(__msg_copy_singular) ._M_iterator(*this, "this") ._M_iterator(__x, "other")); if (this->_M_sequence && this->_M_sequence == __x._M_sequence) { __gnu_cxx::__scoped_lock __l(this->_M_get_mutex()); base() = __x.base(); _M_version = __x._M_sequence->_M_version; } else { _M_detach(); base() = __x.base(); _M_attach(__x._M_sequence); } return *this; } #if __cplusplus >= 201103L /** * @brief Move assignment. * @post __x is singular and unattached */ _Safe_iterator& operator=(_Safe_iterator&& __x) noexcept { _GLIBCXX_DEBUG_VERIFY(this != &__x, _M_message(__msg_self_move_assign) ._M_iterator(*this, "this")); _GLIBCXX_DEBUG_VERIFY(!__x._M_singular() || __x.base() == _Iterator(), _M_message(__msg_copy_singular) ._M_iterator(*this, "this") ._M_iterator(__x, "other")); if (this->_M_sequence && this->_M_sequence == __x._M_sequence) { __gnu_cxx::__scoped_lock __l(this->_M_get_mutex()); base() = __x.base(); _M_version = __x._M_sequence->_M_version; } else { _M_detach(); base() = __x.base(); _M_attach(__x._M_sequence); } __x._M_detach(); __x.base() = _Iterator(); return *this; } #endif /** * @brief Iterator dereference. * @pre iterator is dereferenceable */ reference operator*() const _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(this->_M_dereferenceable(), _M_message(__msg_bad_deref) ._M_iterator(*this, "this")); return *base(); } /** * @brief Iterator dereference. * @pre iterator is dereferenceable */ pointer operator->() const _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(this->_M_dereferenceable(), _M_message(__msg_bad_deref) ._M_iterator(*this, "this")); return base().operator->(); } // ------ Input iterator requirements ------ /** * @brief Iterator preincrement * @pre iterator is incrementable */ _Safe_iterator& operator++() _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(this->_M_incrementable(), _M_message(__msg_bad_inc) ._M_iterator(*this, "this")); __gnu_cxx::__scoped_lock __l(this->_M_get_mutex()); ++base(); return *this; } /** * @brief Iterator postincrement * @pre iterator is incrementable */ _Safe_iterator operator++(int) _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(this->_M_incrementable(), _M_message(__msg_bad_inc) ._M_iterator(*this, "this")); __gnu_cxx::__scoped_lock __l(this->_M_get_mutex()); return _Safe_iterator(base()++, this->_M_sequence, _Attach_single()); } // ------ Bidirectional iterator requirements ------ /** * @brief Iterator predecrement * @pre iterator is decrementable */ _Safe_iterator& operator--() _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(this->_M_decrementable(), _M_message(__msg_bad_dec) ._M_iterator(*this, "this")); __gnu_cxx::__scoped_lock __l(this->_M_get_mutex()); --base(); return *this; } /** * @brief Iterator postdecrement * @pre iterator is decrementable */ _Safe_iterator operator--(int) _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(this->_M_decrementable(), _M_message(__msg_bad_dec) ._M_iterator(*this, "this")); __gnu_cxx::__scoped_lock __l(this->_M_get_mutex()); return _Safe_iterator(base()--, this->_M_sequence, _Attach_single()); } // ------ Random access iterator requirements ------ reference operator[](const difference_type& __n) const _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(this->_M_can_advance(__n) && this->_M_can_advance(__n+1), _M_message(__msg_iter_subscript_oob) ._M_iterator(*this)._M_integer(__n)); return base()[__n]; } _Safe_iterator& operator+=(const difference_type& __n) _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(this->_M_can_advance(__n), _M_message(__msg_advance_oob) ._M_iterator(*this)._M_integer(__n)); __gnu_cxx::__scoped_lock __l(this->_M_get_mutex()); base() += __n; return *this; } _Safe_iterator operator+(const difference_type& __n) const _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(this->_M_can_advance(__n), _M_message(__msg_advance_oob) ._M_iterator(*this)._M_integer(__n)); return _Safe_iterator(base() + __n, this->_M_sequence); } _Safe_iterator& operator-=(const difference_type& __n) _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(this->_M_can_advance(-__n), _M_message(__msg_retreat_oob) ._M_iterator(*this)._M_integer(__n)); __gnu_cxx::__scoped_lock __l(this->_M_get_mutex()); base() -= __n; return *this; } _Safe_iterator operator-(const difference_type& __n) const _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(this->_M_can_advance(-__n), _M_message(__msg_retreat_oob) ._M_iterator(*this)._M_integer(__n)); return _Safe_iterator(base() - __n, this->_M_sequence); } // ------ Utilities ------ /** * @brief Return the underlying iterator */ _Iterator& base() _GLIBCXX_NOEXCEPT { return *this; } const _Iterator& base() const _GLIBCXX_NOEXCEPT { return *this; } /** * @brief Conversion to underlying non-debug iterator to allow * better interaction with non-debug containers. */ operator _Iterator() const _GLIBCXX_NOEXCEPT { return *this; } /** Attach iterator to the given sequence. */ void _M_attach(_Safe_sequence_base* __seq) { _Safe_base::_M_attach(__seq, _M_constant()); } /** Likewise, but not thread-safe. */ void _M_attach_single(_Safe_sequence_base* __seq) { _Safe_base::_M_attach_single(__seq, _M_constant()); } /// Is the iterator dereferenceable? bool _M_dereferenceable() const { return !this->_M_singular() && !_M_is_end() && !_M_is_before_begin(); } /// Is the iterator before a dereferenceable one? bool _M_before_dereferenceable() const { if (this->_M_incrementable()) { _Iterator __base = base(); return ++__base != _M_get_sequence()->_M_base().end(); } return false; } /// Is the iterator incrementable? bool _M_incrementable() const { return !this->_M_singular() && !_M_is_end(); } // Is the iterator decrementable? bool _M_decrementable() const { return !_M_singular() && !_M_is_begin(); } // Can we advance the iterator @p __n steps (@p __n may be negative) bool _M_can_advance(const difference_type& __n) const; // Is the iterator range [*this, __rhs) valid? bool _M_valid_range(const _Safe_iterator& __rhs, std::pair<difference_type, _Distance_precision>& __dist, bool __check_dereferenceable = true) const; // The sequence this iterator references. typename __gnu_cxx::__conditional_type<std::__are_same<_Const_iterator, _Safe_iterator>::__value, const _Sequence*, _Sequence*>::__type _M_get_sequence() const { return static_cast<_Sequence*>(_M_sequence); } /// Is this iterator equal to the sequence's begin() iterator? bool _M_is_begin() const { return base() == _M_get_sequence()->_M_base().begin(); } /// Is this iterator equal to the sequence's end() iterator? bool _M_is_end() const { return base() == _M_get_sequence()->_M_base().end(); } /// Is this iterator equal to the sequence's before_begin() iterator if /// any? bool _M_is_before_begin() const { return _BeforeBeginHelper<_Sequence>::_S_Is(*this); } /// Is this iterator equal to the sequence's before_begin() iterator if /// any or begin() otherwise? bool _M_is_beginnest() const { return _BeforeBeginHelper<_Sequence>::_S_Is_Beginnest(*this); } }; template<typename _IteratorL, typename _IteratorR, typename _Sequence> inline bool operator==(const _Safe_iterator<_IteratorL, _Sequence>& __lhs, const _Safe_iterator<_IteratorR, _Sequence>& __rhs) _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(), _M_message(__msg_iter_compare_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs), _M_message(__msg_compare_different) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); return __lhs.base() == __rhs.base(); } template<typename _Iterator, typename _Sequence> inline bool operator==(const _Safe_iterator<_Iterator, _Sequence>& __lhs, const _Safe_iterator<_Iterator, _Sequence>& __rhs) _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(), _M_message(__msg_iter_compare_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs), _M_message(__msg_compare_different) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); return __lhs.base() == __rhs.base(); } template<typename _IteratorL, typename _IteratorR, typename _Sequence> inline bool operator!=(const _Safe_iterator<_IteratorL, _Sequence>& __lhs, const _Safe_iterator<_IteratorR, _Sequence>& __rhs) _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(), _M_message(__msg_iter_compare_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs), _M_message(__msg_compare_different) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); return __lhs.base() != __rhs.base(); } template<typename _Iterator, typename _Sequence> inline bool operator!=(const _Safe_iterator<_Iterator, _Sequence>& __lhs, const _Safe_iterator<_Iterator, _Sequence>& __rhs) _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(), _M_message(__msg_iter_compare_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs), _M_message(__msg_compare_different) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); return __lhs.base() != __rhs.base(); } template<typename _IteratorL, typename _IteratorR, typename _Sequence> inline bool operator<(const _Safe_iterator<_IteratorL, _Sequence>& __lhs, const _Safe_iterator<_IteratorR, _Sequence>& __rhs) _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(), _M_message(__msg_iter_order_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs), _M_message(__msg_order_different) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); return __lhs.base() < __rhs.base(); } template<typename _Iterator, typename _Sequence> inline bool operator<(const _Safe_iterator<_Iterator, _Sequence>& __lhs, const _Safe_iterator<_Iterator, _Sequence>& __rhs) _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(), _M_message(__msg_iter_order_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs), _M_message(__msg_order_different) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); return __lhs.base() < __rhs.base(); } template<typename _IteratorL, typename _IteratorR, typename _Sequence> inline bool operator<=(const _Safe_iterator<_IteratorL, _Sequence>& __lhs, const _Safe_iterator<_IteratorR, _Sequence>& __rhs) _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(), _M_message(__msg_iter_order_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs), _M_message(__msg_order_different) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); return __lhs.base() <= __rhs.base(); } template<typename _Iterator, typename _Sequence> inline bool operator<=(const _Safe_iterator<_Iterator, _Sequence>& __lhs, const _Safe_iterator<_Iterator, _Sequence>& __rhs) _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(), _M_message(__msg_iter_order_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs), _M_message(__msg_order_different) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); return __lhs.base() <= __rhs.base(); } template<typename _IteratorL, typename _IteratorR, typename _Sequence> inline bool operator>(const _Safe_iterator<_IteratorL, _Sequence>& __lhs, const _Safe_iterator<_IteratorR, _Sequence>& __rhs) _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(), _M_message(__msg_iter_order_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs), _M_message(__msg_order_different) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); return __lhs.base() > __rhs.base(); } template<typename _Iterator, typename _Sequence> inline bool operator>(const _Safe_iterator<_Iterator, _Sequence>& __lhs, const _Safe_iterator<_Iterator, _Sequence>& __rhs) _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(), _M_message(__msg_iter_order_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs), _M_message(__msg_order_different) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); return __lhs.base() > __rhs.base(); } template<typename _IteratorL, typename _IteratorR, typename _Sequence> inline bool operator>=(const _Safe_iterator<_IteratorL, _Sequence>& __lhs, const _Safe_iterator<_IteratorR, _Sequence>& __rhs) _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(), _M_message(__msg_iter_order_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs), _M_message(__msg_order_different) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); return __lhs.base() >= __rhs.base(); } template<typename _Iterator, typename _Sequence> inline bool operator>=(const _Safe_iterator<_Iterator, _Sequence>& __lhs, const _Safe_iterator<_Iterator, _Sequence>& __rhs) _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(), _M_message(__msg_iter_order_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs), _M_message(__msg_order_different) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); return __lhs.base() >= __rhs.base(); } // _GLIBCXX_RESOLVE_LIB_DEFECTS // According to the resolution of DR179 not only the various comparison // operators but also operator- must accept mixed iterator/const_iterator // parameters. template<typename _IteratorL, typename _IteratorR, typename _Sequence> inline typename _Safe_iterator<_IteratorL, _Sequence>::difference_type operator-(const _Safe_iterator<_IteratorL, _Sequence>& __lhs, const _Safe_iterator<_IteratorR, _Sequence>& __rhs) _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(), _M_message(__msg_distance_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs), _M_message(__msg_distance_different) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); return __lhs.base() - __rhs.base(); } template<typename _Iterator, typename _Sequence> inline typename _Safe_iterator<_Iterator, _Sequence>::difference_type operator-(const _Safe_iterator<_Iterator, _Sequence>& __lhs, const _Safe_iterator<_Iterator, _Sequence>& __rhs) _GLIBCXX_NOEXCEPT { _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(), _M_message(__msg_distance_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs), _M_message(__msg_distance_different) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); return __lhs.base() - __rhs.base(); } template<typename _Iterator, typename _Sequence> inline _Safe_iterator<_Iterator, _Sequence> operator+(typename _Safe_iterator<_Iterator,_Sequence>::difference_type __n, const _Safe_iterator<_Iterator, _Sequence>& __i) _GLIBCXX_NOEXCEPT { return __i + __n; } /** Safe iterators know if they are dereferenceable. */ template<typename _Iterator, typename _Sequence> inline bool __check_dereferenceable(const _Safe_iterator<_Iterator, _Sequence>& __x) { return __x._M_dereferenceable(); } /** Safe iterators know how to check if they form a valid range. */ template<typename _Iterator, typename _Sequence> inline bool __valid_range(const _Safe_iterator<_Iterator, _Sequence>& __first, const _Safe_iterator<_Iterator, _Sequence>& __last, typename _Distance_traits<_Iterator>::__type& __dist) { return __first._M_valid_range(__last, __dist); } /** Safe iterators can help to get better distance knowledge. */ template<typename _Iterator, typename _Sequence> inline typename _Distance_traits<_Iterator>::__type __get_distance(const _Safe_iterator<_Iterator, _Sequence>& __first, const _Safe_iterator<_Iterator, _Sequence>& __last, std::random_access_iterator_tag) { return std::make_pair(__last.base() - __first.base(), __dp_exact); } template<typename _Iterator, typename _Sequence> inline typename _Distance_traits<_Iterator>::__type __get_distance(const _Safe_iterator<_Iterator, _Sequence>& __first, const _Safe_iterator<_Iterator, _Sequence>& __last, std::input_iterator_tag) { typedef typename _Distance_traits<_Iterator>::__type _Diff; typedef _Sequence_traits<_Sequence> _SeqTraits; if (__first.base() == __last.base()) return std::make_pair(0, __dp_exact); if (__first._M_is_before_begin()) { if (__last._M_is_begin()) return std::make_pair(1, __dp_exact); return std::make_pair(1, __dp_sign); } if (__first._M_is_begin()) { if (__last._M_is_before_begin()) return std::make_pair(-1, __dp_exact); if (__last._M_is_end()) return _SeqTraits::_S_size(*__first._M_get_sequence()); return std::make_pair(1, __dp_sign); } if (__first._M_is_end()) { if (__last._M_is_before_begin()) return std::make_pair(-1, __dp_exact); if (__last._M_is_begin()) { _Diff __diff = _SeqTraits::_S_size(*__first._M_get_sequence()); return std::make_pair(-__diff.first, __diff.second); } return std::make_pair(-1, __dp_sign); } if (__last._M_is_before_begin() || __last._M_is_begin()) return std::make_pair(-1, __dp_sign); if (__last._M_is_end()) return std::make_pair(1, __dp_sign); return std::make_pair(1, __dp_equality); } // Get distance from sequence begin to specified iterator. template<typename _Iterator, typename _Sequence> inline typename _Distance_traits<_Iterator>::__type __get_distance_from_begin(const _Safe_iterator<_Iterator, _Sequence>& __it) { typedef _Sequence_traits<_Sequence> _SeqTraits; // No need to consider before_begin as this function is only used in // _M_can_advance which won't be used for forward_list iterators. if (__it._M_is_begin()) return std::make_pair(0, __dp_exact); if (__it._M_is_end()) return _SeqTraits::_S_size(*__it._M_get_sequence()); typename _Distance_traits<_Iterator>::__type __res = __get_distance(__it._M_get_sequence()->_M_base().begin(), __it.base()); if (__res.second == __dp_equality) return std::make_pair(1, __dp_sign); return __res; } // Get distance from specified iterator to sequence end. template<typename _Iterator, typename _Sequence> inline typename _Distance_traits<_Iterator>::__type __get_distance_to_end(const _Safe_iterator<_Iterator, _Sequence>& __it) { typedef _Sequence_traits<_Sequence> _SeqTraits; // No need to consider before_begin as this function is only used in // _M_can_advance which won't be used for forward_list iterators. if (__it._M_is_begin()) return _SeqTraits::_S_size(*__it._M_get_sequence()); if (__it._M_is_end()) return std::make_pair(0, __dp_exact); typename _Distance_traits<_Iterator>::__type __res = __get_distance(__it.base(), __it._M_get_sequence()->_M_base().end()); if (__res.second == __dp_equality) return std::make_pair(1, __dp_sign); return __res; } #if __cplusplus < 201103L template<typename _Iterator, typename _Sequence> struct __is_safe_random_iterator<_Safe_iterator<_Iterator, _Sequence> > : std::__are_same<std::random_access_iterator_tag, typename std::iterator_traits<_Iterator>:: iterator_category> { }; #else template<typename _Iterator, typename _Sequence> _Iterator __base(const _Safe_iterator<_Iterator, _Sequence>& __it, std::random_access_iterator_tag) { return __it.base(); } template<typename _Iterator, typename _Sequence> const _Safe_iterator<_Iterator, _Sequence>& __base(const _Safe_iterator<_Iterator, _Sequence>& __it, std::input_iterator_tag) { return __it; } template<typename _Iterator, typename _Sequence> auto __base(const _Safe_iterator<_Iterator, _Sequence>& __it) -> decltype(__base(__it, std::__iterator_category(__it))) { return __base(__it, std::__iterator_category(__it)); } #endif #if __cplusplus < 201103L template<typename _Iterator, typename _Sequence> struct _Unsafe_type<_Safe_iterator<_Iterator, _Sequence> > { typedef _Iterator _Type; }; #endif template<typename _Iterator, typename _Sequence> inline _Iterator __unsafe(const _Safe_iterator<_Iterator, _Sequence>& __it) { return __it.base(); } } // namespace __gnu_debug #include <debug/safe_iterator.tcc> #endif
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