// List implementation -*- C++ -*- // Copyright (C) 2001, 2002 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 2, 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. // You should have received a copy of the GNU General Public License along // with this library; see the file COPYING. If not, write to the Free // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, // USA. // As a special exception, you may use this file as part of a free software // library without restriction. Specifically, if other files instantiate // templates or use macros or inline functions from this file, or you compile // this file and link it with other files to produce an executable, this // file does not by itself cause the resulting executable to be covered by // the GNU General Public License. This exception does not however // invalidate any other reasons why the executable file might be covered by // the GNU General Public License. /* * * Copyright (c) 1994 * Hewlett-Packard Company * * Permission to use, copy, modify, distribute and sell this software * and its documentation for any purpose is hereby granted without fee, * provided that the above copyright notice appear in all copies and * that both that copyright notice and this permission notice appear * in supporting documentation. Hewlett-Packard Company makes no * representations about the suitability of this software for any * purpose. It is provided "as is" without express or implied warranty. * * * Copyright (c) 1996,1997 * Silicon Graphics Computer Systems, Inc. * * Permission to use, copy, modify, distribute and sell this software * and its documentation for any purpose is hereby granted without fee, * provided that the above copyright notice appear in all copies and * that both that copyright notice and this permission notice appear * in supporting documentation. Silicon Graphics makes no * representations about the suitability of this software for any * purpose. It is provided "as is" without express or implied warranty. */ /** @file stl_list.h * This is an internal header file, included by other library headers. * You should not attempt to use it directly. */ #ifndef __GLIBCPP_INTERNAL_LIST_H #define __GLIBCPP_INTERNAL_LIST_H #include namespace std { // Supporting structures are split into common and templated types; the // latter publicly inherits from the former in an effort to reduce code // duplication. This results in some "needless" static_cast'ing later on, // but it's all safe downcasting. /// @if maint Common part of a node in the %list. @endif struct _List_node_base { _List_node_base* _M_next; ///< Self-explanatory _List_node_base* _M_prev; ///< Self-explanatory }; /// @if maint An actual node in the %list. @endif template struct _List_node : public _List_node_base { _Tp _M_data; ///< User's data. }; /** * @if maint * @brief Common part of a list::iterator. * * A simple type to walk a doubly-linked list. All operations here should * be self-explanatory after taking any decent introductory data structures * course. * @endif */ struct _List_iterator_base { typedef size_t size_type; typedef ptrdiff_t difference_type; typedef bidirectional_iterator_tag iterator_category; /// The only member points to the %list element. _List_node_base* _M_node; _List_iterator_base(_List_node_base* __x) : _M_node(__x) { } _List_iterator_base() { } /// Walk the %list forward. void _M_incr() { _M_node = _M_node->_M_next; } /// Walk the %list backward. void _M_decr() { _M_node = _M_node->_M_prev; } bool operator==(const _List_iterator_base& __x) const { return _M_node == __x._M_node; } bool operator!=(const _List_iterator_base& __x) const { return _M_node != __x._M_node; } }; /** * @brief A list::iterator. * * In addition to being used externally, a list holds one of these * internally, pointing to the sequence of data. * * @if maint * All the functions are op overloads. * @endif */ template struct _List_iterator : public _List_iterator_base { typedef _List_iterator<_Tp,_Tp&,_Tp*> iterator; typedef _List_iterator<_Tp,const _Tp&,const _Tp*> const_iterator; typedef _List_iterator<_Tp,_Ref,_Ptr> _Self; typedef _Tp value_type; typedef _Ptr pointer; typedef _Ref reference; typedef _List_node<_Tp> _Node; _List_iterator(_Node* __x) : _List_iterator_base(__x) { } _List_iterator() { } _List_iterator(const iterator& __x) : _List_iterator_base(__x._M_node) { } reference operator*() const { return static_cast<_Node*>(_M_node)->_M_data; } // Must downcast from List_node_base to _List_node to get to _M_data. pointer operator->() const { return &(operator*()); } _Self& operator++() { this->_M_incr(); return *this; } _Self operator++(int) { _Self __tmp = *this; this->_M_incr(); return __tmp; } _Self& operator--() { this->_M_decr(); return *this; } _Self operator--(int) { _Self __tmp = *this; this->_M_decr(); return __tmp; } }; /// @if maint Primary default version. @endif /** * @if maint * See bits/stl_deque.h's _Deque_alloc_base for an explanation. * @endif */ template class _List_alloc_base { public: typedef typename _Alloc_traits<_Tp, _Allocator>::allocator_type allocator_type; allocator_type get_allocator() const { return _M_node_allocator; } _List_alloc_base(const allocator_type& __a) : _M_node_allocator(__a) { } protected: _List_node<_Tp>* _M_get_node() { return _M_node_allocator.allocate(1); } void _M_put_node(_List_node<_Tp>* __p) { _M_node_allocator.deallocate(__p, 1); } // NOTA BENE // The stored instance is not actually of "allocator_type"'s type. Instead // we rebind the type to Allocator>, which according to // [20.1.5]/4 should probably be the same. List_node is not the same // size as Tp (it's two pointers larger), and specializations on Tp may go // unused because List_node is being bound instead. // // We put this to the test in get_allocator above; if the two types are // actually different, there had better be a conversion between them. // // None of the predefined allocators shipped with the library (as of 3.1) // use this instantiation anyhow; they're all instanceless. typename _Alloc_traits<_List_node<_Tp>, _Allocator>::allocator_type _M_node_allocator; _List_node<_Tp>* _M_node; }; /// @if maint Specialization for instanceless allocators. @endif template class _List_alloc_base<_Tp, _Allocator, true> { public: typedef typename _Alloc_traits<_Tp, _Allocator>::allocator_type allocator_type; allocator_type get_allocator() const { return allocator_type(); } _List_alloc_base(const allocator_type&) { } protected: // See comment in primary template class about why this is safe for the // standard predefined classes. typedef typename _Alloc_traits<_List_node<_Tp>, _Allocator>::_Alloc_type _Alloc_type; _List_node<_Tp>* _M_get_node() { return _Alloc_type::allocate(1); } void _M_put_node(_List_node<_Tp>* __p) { _Alloc_type::deallocate(__p, 1); } _List_node<_Tp>* _M_node; }; /** * @if maint * See bits/stl_deque.h's _Deque_base for an explanation. * @endif */ template class _List_base : public _List_alloc_base<_Tp, _Alloc, _Alloc_traits<_Tp, _Alloc>::_S_instanceless> { public: typedef _List_alloc_base<_Tp, _Alloc, _Alloc_traits<_Tp, _Alloc>::_S_instanceless> _Base; typedef typename _Base::allocator_type allocator_type; _List_base(const allocator_type& __a) : _Base(__a) { _M_node = _M_get_node(); _M_node->_M_next = _M_node; _M_node->_M_prev = _M_node; } // This is what actually destroys the list. ~_List_base() { __clear(); _M_put_node(_M_node); } void __clear(); }; /** * @brief A standard container with linear time access to elements, and * fixed time insertion/deletion at any point in the sequence. * * @ingroup Containers * @ingroup Sequences * * Meets the requirements of a container, a * reversible container, and a * sequence, including the * optional sequence requirements with the * %exception of @c at and @c operator[]. * * This is a @e doubly @e linked %list. Traversal up and down the %list * requires linear time, but adding and removing elements (or @e nodes) is * done in constant time, regardless of where the change takes place. * Unlike std::vector and std::deque, random-access iterators are not * provided, so subscripting ( @c [] ) access is not allowed. For algorithms * which only need sequential access, this lack makes no difference. * * Also unlike the other standard containers, std::list provides specialized * algorithms %unique to linked lists, such as splicing, sorting, and * in-place reversal. * * @if maint * A couple points on memory allocation for list: * * First, we never actually allocate a Tp, we allocate List_node's * and trust [20.1.5]/4 to DTRT. This is to ensure that after elements from * %list are spliced into %list, destroying the memory of * the second %list is a valid operation, i.e., Alloc1 giveth and Alloc2 * taketh away. * * Second, a %list conceptually represented as * @code * A <---> B <---> C <---> D * @endcode * is actually circular; a link exists between A and D. The %list class * holds (as its only data member) a private list::iterator pointing to * @e D, not to @e A! To get to the head of the %list, we start at the tail * and move forward by one. When this member iterator's next/previous * pointers refer to itself, the %list is %empty. * @endif */ template > class list : protected _List_base<_Tp, _Alloc> { // concept requirements __glibcpp_class_requires(_Tp, _SGIAssignableConcept) typedef _List_base<_Tp, _Alloc> _Base; public: typedef _Tp value_type; typedef value_type* pointer; typedef const value_type* const_pointer; typedef _List_iterator<_Tp,_Tp&,_Tp*> iterator; typedef _List_iterator<_Tp,const _Tp&,const _Tp*> const_iterator; typedef std::reverse_iterator const_reverse_iterator; typedef std::reverse_iterator reverse_iterator; typedef value_type& reference; typedef const value_type& const_reference; typedef size_t size_type; typedef ptrdiff_t difference_type; typedef typename _Base::allocator_type allocator_type; protected: // Note that pointers-to-_Node's can be ctor-converted to iterator types. typedef _List_node<_Tp> _Node; /** @if maint * One data member plus two memory-handling functions. If the _Alloc * type requires separate instances, then one of those will also be * included, accumulated from the topmost parent. * @endif */ using _Base::_M_node; using _Base::_M_put_node; using _Base::_M_get_node; /** * @if maint * @param x An instance of user data. * * Allocates space for a new node and constructs a copy of @a x in it. * @endif */ _Node* _M_create_node(const value_type& __x) { _Node* __p = _M_get_node(); try { _Construct(&__p->_M_data, __x); } catch(...) { _M_put_node(__p); __throw_exception_again; } return __p; } /** * @if maint * Allocates space for a new node and default-constructs a new instance * of @c value_type in it. * @endif */ _Node* _M_create_node() { _Node* __p = _M_get_node(); try { _Construct(&__p->_M_data); } catch(...) { _M_put_node(__p); __throw_exception_again; } return __p; } public: // [23.2.2.1] construct/copy/destroy // (assign() and get_allocator() are also listed in this section) /** * @brief Default constructor creates no elements. */ explicit list(const allocator_type& __a = allocator_type()) : _Base(__a) { } /** * @brief Create a %list with copies of an exemplar element. * @param n The number of elements to initially create. * @param value An element to copy. * * This constructor fills the %list with @a n copies of @a value. */ list(size_type __n, const value_type& __value, const allocator_type& __a = allocator_type()) : _Base(__a) { this->insert(begin(), __n, __value); } /** * @brief Create a %list with default elements. * @param n The number of elements to initially create. * * This constructor fills the %list with @a n copies of a * default-constructed element. */ explicit list(size_type __n) : _Base(allocator_type()) { this->insert(begin(), __n, value_type()); } /** * @brief %List copy constructor. * @param x A %list of identical element and allocator types. * * The newly-created %list uses a copy of the allocation object used * by @a x. */ list(const list& __x) : _Base(__x.get_allocator()) { this->insert(begin(), __x.begin(), __x.end()); } /** * @brief Builds a %list from a range. * @param first An input iterator. * @param last An input iterator. * * Create a %list consisting of copies of the elements from [first,last). * This is linear in N (where N is distance(first,last)). * * @if maint * We don't need any dispatching tricks here, because insert does all of * that anyway. * @endif */ template list(_InputIterator __first, _InputIterator __last, const allocator_type& __a = allocator_type()) : _Base(__a) { this->insert(begin(), __first, __last); } /** * The dtor only erases the elements, and note that if the elements * themselves are pointers, the pointed-to memory is not touched in any * way. Managing the pointer is the user's responsibilty. */ ~list() { } /** * @brief %List assignment operator. * @param x A %list of identical element and allocator types. * * All the elements of @a x are copied, but unlike the copy constructor, * the allocator object is not copied. */ list& operator=(const list& __x); /** * @brief Assigns a given value to a %list. * @param n Number of elements to be assigned. * @param val Value to be assigned. * * This function fills a %list with @a n copies of the given value. * Note that the assignment completely changes the %list and that the * resulting %list's size is the same as the number of elements assigned. * Old data may be lost. */ void assign(size_type __n, const value_type& __val) { _M_fill_assign(__n, __val); } /** * @brief Assigns a range to a %list. * @param first An input iterator. * @param last An input iterator. * * This function fills a %list with copies of the elements in the * range [first,last). * * Note that the assignment completely changes the %list and that the * resulting %list's size is the same as the number of elements assigned. * Old data may be lost. */ template void assign(_InputIterator __first, _InputIterator __last) { // Check whether it's an integral type. If so, it's not an iterator. typedef typename _Is_integer<_InputIterator>::_Integral _Integral; _M_assign_dispatch(__first, __last, _Integral()); } /// Get a copy of the memory allocation object. allocator_type get_allocator() const { return _Base::get_allocator(); } // iterators /** * Returns a read/write iterator that points to the first element in the * %list. Iteration is done in ordinary element order. */ iterator begin() { return static_cast<_Node*>(_M_node->_M_next); } /** * Returns a read-only (constant) iterator that points to the first element * in the %list. Iteration is done in ordinary element order. */ const_iterator begin() const { return static_cast<_Node*>(_M_node->_M_next); } /** * Returns a read/write iterator that points one past the last element in * the %list. Iteration is done in ordinary element order. */ iterator end() { return _M_node; } /** * Returns a read-only (constant) iterator that points one past the last * element in the %list. Iteration is done in ordinary element order. */ const_iterator end() const { return _M_node; } /** * Returns a read/write reverse iterator that points to the last element in * the %list. Iteration is done in reverse element order. */ reverse_iterator rbegin() { return reverse_iterator(end()); } /** * Returns a read-only (constant) reverse iterator that points to the last * element in the %list. Iteration is done in reverse element order. */ const_reverse_iterator rbegin() const { return const_reverse_iterator(end()); } /** * Returns a read/write reverse iterator that points to one before the * first element in the %list. Iteration is done in reverse element * order. */ reverse_iterator rend() { return reverse_iterator(begin()); } /** * Returns a read-only (constant) reverse iterator that points to one * before the first element in the %list. Iteration is done in reverse * element order. */ const_reverse_iterator rend() const { return const_reverse_iterator(begin()); } // [23.2.2.2] capacity /** * Returns true if the %list is empty. (Thus begin() would equal end().) */ bool empty() const { return _M_node->_M_next == _M_node; } /** Returns the number of elements in the %list. */ size_type size() const { return distance(begin(), end()); } /** Returns the size() of the largest possible %list. */ size_type max_size() const { return size_type(-1); } /** * @brief Resizes the %list to the specified number of elements. * @param new_size Number of elements the %list should contain. * @param x Data with which new elements should be populated. * * This function will %resize the %list to the specified number of * elements. If the number is smaller than the %list's current size the * %list is truncated, otherwise the %list is extended and new elements * are populated with given data. */ void resize(size_type __new_size, const value_type& __x); /** * @brief Resizes the %list to the specified number of elements. * @param new_size Number of elements the %list should contain. * * This function will resize the %list to the specified number of * elements. If the number is smaller than the %list's current size the * %list is truncated, otherwise the %list is extended and new elements * are default-constructed. */ void resize(size_type __new_size) { this->resize(__new_size, value_type()); } // element access /** * Returns a read/write reference to the data at the first element of the * %list. */ reference front() { return *begin(); } /** * Returns a read-only (constant) reference to the data at the first * element of the %list. */ const_reference front() const { return *begin(); } /** * Returns a read/write reference to the data at the last element of the * %list. */ reference back() { return *(--end()); } /** * Returns a read-only (constant) reference to the data at the last * element of the %list. */ const_reference back() const { return *(--end()); } // [23.2.2.3] modifiers /** * @brief Add data to the front of the %list. * @param x Data to be added. * * This is a typical stack operation. The function creates an element at * the front of the %list and assigns the given data to it. Due to the * nature of a %list this operation can be done in constant time, and * does not invalidate iterators and references. */ void push_front(const value_type& __x) { this->insert(begin(), __x); } #ifdef _GLIBCPP_DEPRECATED /** * @brief Add data to the front of the %list. * * This is a typical stack operation. The function creates a * default-constructed element at the front of the %list. Due to the * nature of a %list this operation can be done in constant time. You * should consider using push_front(value_type()) instead. * * @note This was deprecated in 3.2 and will be removed in 3.4. You must * define @c _GLIBCPP_DEPRECATED to make this visible in 3.2; see * c++config.h. */ void push_front() { this->insert(begin(), value_type()); } #endif /** * @brief Removes first element. * * This is a typical stack operation. It shrinks the %list by one. * Due to the nature of a %list this operation can be done in constant * time, and only invalidates iterators/references to the element being * removed. * * Note that no data is returned, and if the first element's data is * needed, it should be retrieved before pop_front() is called. */ void pop_front() { this->erase(begin()); } /** * @brief Add data to the end of the %list. * @param x Data to be added. * * This is a typical stack operation. The function creates an element at * the end of the %list and assigns the given data to it. Due to the * nature of a %list this operation can be done in constant time, and * does not invalidate iterators and references. */ void push_back(const value_type& __x) { this->insert(end(), __x); } #ifdef _GLIBCPP_DEPRECATED /** * @brief Add data to the end of the %list. * * This is a typical stack operation. The function creates a * default-constructed element at the end of the %list. Due to the nature * of a %list this operation can be done in constant time. You should * consider using push_back(value_type()) instead. * * @note This was deprecated in 3.2 and will be removed in 3.4. You must * define @c _GLIBCPP_DEPRECATED to make this visible in 3.2; see * c++config.h. */ void push_back() { this->insert(end(), value_type()); } #endif /** * @brief Removes last element. * * This is a typical stack operation. It shrinks the %list by one. * Due to the nature of a %list this operation can be done in constant * time, and only invalidates iterators/references to the element being * removed. * * Note that no data is returned, and if the last element's data is * needed, it should be retrieved before pop_back() is called. */ void pop_back() { iterator __tmp = end(); this->erase(--__tmp); } /** * @brief Inserts given value into %list before specified iterator. * @param position An iterator into the %list. * @param x Data to be inserted. * @return An iterator that points to the inserted data. * * This function will insert a copy of the given value before the specified * location. * Due to the nature of a %list this operation can be done in constant * time, and does not invalidate iterators and references. */ iterator insert(iterator __position, const value_type& __x); #ifdef _GLIBCPP_DEPRECATED /** * @brief Inserts an element into the %list. * @param position An iterator into the %list. * @return An iterator that points to the inserted element. * * This function will insert a default-constructed element before the * specified location. You should consider using * insert(position,value_type()) instead. * Due to the nature of a %list this operation can be done in constant * time, and does not invalidate iterators and references. * * @note This was deprecated in 3.2 and will be removed in 3.4. You must * define @c _GLIBCPP_DEPRECATED to make this visible in 3.2; see * c++config.h. */ iterator insert(iterator __position) { return insert(__position, value_type()); } #endif /** * @brief Inserts a number of copies of given data into the %list. * @param position An iterator into the %list. * @param n Number of elements to be inserted. * @param x Data to be inserted. * * This function will insert a specified number of copies of the given data * before the location specified by @a position. * * Due to the nature of a %list this operation can be done in constant * time, and does not invalidate iterators and references. */ void insert(iterator __pos, size_type __n, const value_type& __x) { _M_fill_insert(__pos, __n, __x); } /** * @brief Inserts a range into the %list. * @param pos An iterator into the %list. * @param first An input iterator. * @param last An input iterator. * * This function will insert copies of the data in the range [first,last) * into the %list before the location specified by @a pos. * * Due to the nature of a %list this operation can be done in constant * time, and does not invalidate iterators and references. */ template void insert(iterator __pos, _InputIterator __first, _InputIterator __last) { // Check whether it's an integral type. If so, it's not an iterator. typedef typename _Is_integer<_InputIterator>::_Integral _Integral; _M_insert_dispatch(__pos, __first, __last, _Integral()); } /** * @brief Remove element at given position. * @param position Iterator pointing to element to be erased. * @return An iterator pointing to the next element (or end()). * * This function will erase the element at the given position and thus * shorten the %list by one. * * Due to the nature of a %list this operation can be done in constant * time, and only invalidates iterators/references to the element being * removed. * The user is also cautioned that * this function only erases the element, and that if the element is itself * a pointer, the pointed-to memory is not touched in any way. Managing * the pointer is the user's responsibilty. */ iterator erase(iterator __position); /** * @brief Remove a range of elements. * @param first Iterator pointing to the first element to be erased. * @param last Iterator pointing to one past the last element to be * erased. * @return An iterator pointing to the element pointed to by @a last * prior to erasing (or end()). * * This function will erase the elements in the range [first,last) and * shorten the %list accordingly. * * Due to the nature of a %list this operation can be done in constant * time, and only invalidates iterators/references to the element being * removed. * The user is also cautioned that * this function only erases the elements, and that if the elements * themselves are pointers, the pointed-to memory is not touched in any * way. Managing the pointer is the user's responsibilty. */ iterator erase(iterator __first, iterator __last) { while (__first != __last) erase(__first++); return __last; } /** * @brief Swaps data with another %list. * @param x A %list of the same element and allocator types. * * This exchanges the elements between two lists in constant time. * (It is only swapping a single pointer, so it should be quite fast.) * Note that the global std::swap() function is specialized such that * std::swap(l1,l2) will feed to this function. */ void swap(list& __x) { std::swap(_M_node, __x._M_node); } /** * Erases all the elements. Note that this function only erases the * elements, and that if the elements themselves are pointers, the * pointed-to memory is not touched in any way. Managing the pointer is * the user's responsibilty. */ void clear() { _Base::__clear(); } // [23.2.2.4] list operations /** * @doctodo */ void splice(iterator __position, list& __x) { if (!__x.empty()) this->_M_transfer(__position, __x.begin(), __x.end()); } /** * @doctodo */ void splice(iterator __position, list&, iterator __i) { iterator __j = __i; ++__j; if (__position == __i || __position == __j) return; this->_M_transfer(__position, __i, __j); } /** * @doctodo */ void splice(iterator __position, list&, iterator __first, iterator __last) { if (__first != __last) this->_M_transfer(__position, __first, __last); } /** * @doctodo */ void remove(const _Tp& __value); /** * @doctodo */ template void remove_if(_Predicate); /** * @doctodo */ void unique(); /** * @doctodo */ template void unique(_BinaryPredicate); /** * @doctodo */ void merge(list& __x); /** * @doctodo */ template void merge(list&, _StrictWeakOrdering); /** * @doctodo */ void reverse() { __List_base_reverse(this->_M_node); } /** * @doctodo */ void sort(); /** * @doctodo */ template void sort(_StrictWeakOrdering); protected: // Internal assign functions follow. // called by the range assign to implement [23.1.1]/9 template void _M_assign_dispatch(_Integer __n, _Integer __val, __true_type) { _M_fill_assign(static_cast(__n), static_cast(__val)); } // called by the range assign to implement [23.1.1]/9 template void _M_assign_dispatch(_InputIter __first, _InputIter __last, __false_type); // Called by assign(n,t), and the range assign when it turns out to be the // same thing. void _M_fill_assign(size_type __n, const value_type& __val); // Internal insert functions follow. // called by the range insert to implement [23.1.1]/9 template void _M_insert_dispatch(iterator __pos, _Integer __n, _Integer __x, __true_type) { _M_fill_insert(__pos, static_cast(__n), static_cast(__x)); } // called by the range insert to implement [23.1.1]/9 template void _M_insert_dispatch(iterator __pos, _InputIterator __first, _InputIterator __last, __false_type) { for ( ; __first != __last; ++__first) insert(__pos, *__first); } // Called by insert(p,n,x), and the range insert when it turns out to be // the same thing. void _M_fill_insert(iterator __pos, size_type __n, const value_type& __x) { for ( ; __n > 0; --__n) insert(__pos, __x); } // Moves the elements from [first,last) before position. void _M_transfer(iterator __position, iterator __first, iterator __last) { if (__position != __last) { // Remove [first, last) from its old position. __last._M_node->_M_prev->_M_next = __position._M_node; __first._M_node->_M_prev->_M_next = __last._M_node; __position._M_node->_M_prev->_M_next = __first._M_node; // Splice [first, last) into its new position. _List_node_base* __tmp = __position._M_node->_M_prev; __position._M_node->_M_prev = __last._M_node->_M_prev; __last._M_node->_M_prev = __first._M_node->_M_prev; __first._M_node->_M_prev = __tmp; } } }; /** * @brief List equality comparison. * @param x A %list. * @param y A %list of the same type as @a x. * @return True iff the size and elements of the lists are equal. * * This is an equivalence relation. It is linear in the size of the * lists. Lists are considered equivalent if their sizes are equal, * and if corresponding elements compare equal. */ template inline bool operator==(const list<_Tp,_Alloc>& __x, const list<_Tp,_Alloc>& __y) { typedef typename list<_Tp,_Alloc>::const_iterator const_iterator; const_iterator __end1 = __x.end(); const_iterator __end2 = __y.end(); const_iterator __i1 = __x.begin(); const_iterator __i2 = __y.begin(); while (__i1 != __end1 && __i2 != __end2 && *__i1 == *__i2) { ++__i1; ++__i2; } return __i1 == __end1 && __i2 == __end2; } /** * @brief List ordering relation. * @param x A %list. * @param y A %list of the same type as @a x. * @return True iff @a x is lexographically less than @a y. * * This is a total ordering relation. It is linear in the size of the * lists. The elements must be comparable with @c <. * * See std::lexographical_compare() for how the determination is made. */ template inline bool operator<(const list<_Tp,_Alloc>& __x, const list<_Tp,_Alloc>& __y) { return lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end()); } /// Based on operator== template inline bool operator!=(const list<_Tp,_Alloc>& __x, const list<_Tp,_Alloc>& __y) { return !(__x == __y); } /// Based on operator< template inline bool operator>(const list<_Tp,_Alloc>& __x, const list<_Tp,_Alloc>& __y) { return __y < __x; } /// Based on operator< template inline bool operator<=(const list<_Tp,_Alloc>& __x, const list<_Tp,_Alloc>& __y) { return !(__y < __x); } /// Based on operator< template inline bool operator>=(const list<_Tp,_Alloc>& __x, const list<_Tp,_Alloc>& __y) { return !(__x < __y); } /// See std::list::swap(). template inline void swap(list<_Tp, _Alloc>& __x, list<_Tp, _Alloc>& __y) { __x.swap(__y); } } // namespace std #endif /* __GLIBCPP_INTERNAL_LIST_H */