// Iterators -*- C++ -*- // Copyright (C) 2001, 2002, 2004 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) 1996-1998 * 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_iterator.h * This is an internal header file, included by other library headers. * You should not attempt to use it directly. * * This file implements reverse_iterator, back_insert_iterator, * front_insert_iterator, insert_iterator, __normal_iterator, and their * supporting functions and overloaded operators. */ #ifndef _ITERATOR_H #define _ITERATOR_H 1 namespace std { // 24.4.1 Reverse iterators /** * "Bidirectional and random access iterators have corresponding reverse * %iterator adaptors that iterate through the data structure in the * opposite direction. They have the same signatures as the corresponding * iterators. The fundamental relation between a reverse %iterator and its * corresponding %iterator @c i is established by the identity: * @code * &*(reverse_iterator(i)) == &*(i - 1) * @endcode * * This mapping is dictated by the fact that while there is always a * pointer past the end of an array, there might not be a valid pointer * before the beginning of an array." [24.4.1]/1,2 * * Reverse iterators can be tricky and surprising at first. Their * semantics make sense, however, and the trickiness is a side effect of * the requirement that the iterators must be safe. */ template<typename _Iterator> class reverse_iterator : public iterator<typename iterator_traits<_Iterator>::iterator_category, typename iterator_traits<_Iterator>::value_type, typename iterator_traits<_Iterator>::difference_type, typename iterator_traits<_Iterator>::pointer, typename iterator_traits<_Iterator>::reference> { protected: _Iterator current; public: typedef _Iterator iterator_type; typedef typename iterator_traits<_Iterator>::difference_type difference_type; typedef typename iterator_traits<_Iterator>::reference reference; typedef typename iterator_traits<_Iterator>::pointer pointer; public: /** * The default constructor default-initializes member @p current. * If it is a pointer, that means it is zero-initialized. */ // _GLIBCXX_RESOLVE_LIB_DEFECTS // 235 No specification of default ctor for reverse_iterator reverse_iterator() : current() { } /** * This %iterator will move in the opposite direction that @p x does. */ explicit reverse_iterator(iterator_type __x) : current(__x) { } /** * The copy constructor is normal. */ reverse_iterator(const reverse_iterator& __x) : current(__x.current) { } /** * A reverse_iterator across other types can be copied in the normal * fashion. */ template<typename _Iter> reverse_iterator(const reverse_iterator<_Iter>& __x) : current(__x.base()) { } /** * @return @c current, the %iterator used for underlying work. */ iterator_type base() const { return current; } /** * @return TODO * * @doctodo */ reference operator*() const { _Iterator __tmp = current; return *--__tmp; } /** * @return TODO * * @doctodo */ pointer operator->() const { return &(operator*()); } /** * @return TODO * * @doctodo */ reverse_iterator& operator++() { --current; return *this; } /** * @return TODO * * @doctodo */ reverse_iterator operator++(int) { reverse_iterator __tmp = *this; --current; return __tmp; } /** * @return TODO * * @doctodo */ reverse_iterator& operator--() { ++current; return *this; } /** * @return TODO * * @doctodo */ reverse_iterator operator--(int) { reverse_iterator __tmp = *this; ++current; return __tmp; } /** * @return TODO * * @doctodo */ reverse_iterator operator+(difference_type __n) const { return reverse_iterator(current - __n); } /** * @return TODO * * @doctodo */ reverse_iterator& operator+=(difference_type __n) { current -= __n; return *this; } /** * @return TODO * * @doctodo */ reverse_iterator operator-(difference_type __n) const { return reverse_iterator(current + __n); } /** * @return TODO * * @doctodo */ reverse_iterator& operator-=(difference_type __n) { current += __n; return *this; } /** * @return TODO * * @doctodo */ reference operator[](difference_type __n) const { return *(*this + __n); } }; //@{ /** * @param x A %reverse_iterator. * @param y A %reverse_iterator. * @return A simple bool. * * Reverse iterators forward many operations to their underlying base() * iterators. Others are implemented in terms of one another. * */ template<typename _Iterator> inline bool operator==(const reverse_iterator<_Iterator>& __x, const reverse_iterator<_Iterator>& __y) { return __x.base() == __y.base(); } template<typename _Iterator> inline bool operator<(const reverse_iterator<_Iterator>& __x, const reverse_iterator<_Iterator>& __y) { return __y.base() < __x.base(); } template<typename _Iterator> inline bool operator!=(const reverse_iterator<_Iterator>& __x, const reverse_iterator<_Iterator>& __y) { return !(__x == __y); } template<typename _Iterator> inline bool operator>(const reverse_iterator<_Iterator>& __x, const reverse_iterator<_Iterator>& __y) { return __y < __x; } template<typename _Iterator> inline bool operator<=(const reverse_iterator<_Iterator>& __x, const reverse_iterator<_Iterator>& __y) { return !(__y < __x); } template<typename _Iterator> inline bool operator>=(const reverse_iterator<_Iterator>& __x, const reverse_iterator<_Iterator>& __y) { return !(__x < __y); } template<typename _Iterator> inline typename reverse_iterator<_Iterator>::difference_type operator-(const reverse_iterator<_Iterator>& __x, const reverse_iterator<_Iterator>& __y) { return __y.base() - __x.base(); } template<typename _Iterator> inline reverse_iterator<_Iterator> operator+(typename reverse_iterator<_Iterator>::difference_type __n, const reverse_iterator<_Iterator>& __x) { return reverse_iterator<_Iterator>(__x.base() - __n); } //@} // 24.4.2.2.1 back_insert_iterator /** * @brief Turns assignment into insertion. * * These are output iterators, constructed from a container-of-T. * Assigning a T to the iterator appends it to the container using * push_back. * * Tip: Using the back_inserter function to create these iterators can * save typing. */ template<typename _Container> class back_insert_iterator : public iterator<output_iterator_tag, void, void, void, void> { protected: _Container* container; public: /// A nested typedef for the type of whatever container you used. typedef _Container container_type; /// The only way to create this %iterator is with a container. explicit back_insert_iterator(_Container& __x) : container(&__x) { } /** * @param value An instance of whatever type * container_type::const_reference is; presumably a * reference-to-const T for container<T>. * @return This %iterator, for chained operations. * * This kind of %iterator doesn't really have a "position" in the * container (you can think of the position as being permanently at * the end, if you like). Assigning a value to the %iterator will * always append the value to the end of the container. */ back_insert_iterator& operator=(typename _Container::const_reference __value) { container->push_back(__value); return *this; } /// Simply returns *this. back_insert_iterator& operator*() { return *this; } /// Simply returns *this. (This %iterator does not "move".) back_insert_iterator& operator++() { return *this; } /// Simply returns *this. (This %iterator does not "move".) back_insert_iterator operator++(int) { return *this; } }; /** * @param x A container of arbitrary type. * @return An instance of back_insert_iterator working on @p x. * * This wrapper function helps in creating back_insert_iterator instances. * Typing the name of the %iterator requires knowing the precise full * type of the container, which can be tedious and impedes generic * programming. Using this function lets you take advantage of automatic * template parameter deduction, making the compiler match the correct * types for you. */ template<typename _Container> inline back_insert_iterator<_Container> back_inserter(_Container& __x) { return back_insert_iterator<_Container>(__x); } /** * @brief Turns assignment into insertion. * * These are output iterators, constructed from a container-of-T. * Assigning a T to the iterator prepends it to the container using * push_front. * * Tip: Using the front_inserter function to create these iterators can * save typing. */ template<typename _Container> class front_insert_iterator : public iterator<output_iterator_tag, void, void, void, void> { protected: _Container* container; public: /// A nested typedef for the type of whatever container you used. typedef _Container container_type; /// The only way to create this %iterator is with a container. explicit front_insert_iterator(_Container& __x) : container(&__x) { } /** * @param value An instance of whatever type * container_type::const_reference is; presumably a * reference-to-const T for container<T>. * @return This %iterator, for chained operations. * * This kind of %iterator doesn't really have a "position" in the * container (you can think of the position as being permanently at * the front, if you like). Assigning a value to the %iterator will * always prepend the value to the front of the container. */ front_insert_iterator& operator=(typename _Container::const_reference __value) { container->push_front(__value); return *this; } /// Simply returns *this. front_insert_iterator& operator*() { return *this; } /// Simply returns *this. (This %iterator does not "move".) front_insert_iterator& operator++() { return *this; } /// Simply returns *this. (This %iterator does not "move".) front_insert_iterator operator++(int) { return *this; } }; /** * @param x A container of arbitrary type. * @return An instance of front_insert_iterator working on @p x. * * This wrapper function helps in creating front_insert_iterator instances. * Typing the name of the %iterator requires knowing the precise full * type of the container, which can be tedious and impedes generic * programming. Using this function lets you take advantage of automatic * template parameter deduction, making the compiler match the correct * types for you. */ template<typename _Container> inline front_insert_iterator<_Container> front_inserter(_Container& __x) { return front_insert_iterator<_Container>(__x); } /** * @brief Turns assignment into insertion. * * These are output iterators, constructed from a container-of-T. * Assigning a T to the iterator inserts it in the container at the * %iterator's position, rather than overwriting the value at that * position. * * (Sequences will actually insert a @e copy of the value before the * %iterator's position.) * * Tip: Using the inserter function to create these iterators can * save typing. */ template<typename _Container> class insert_iterator : public iterator<output_iterator_tag, void, void, void, void> { protected: _Container* container; typename _Container::iterator iter; public: /// A nested typedef for the type of whatever container you used. typedef _Container container_type; /** * The only way to create this %iterator is with a container and an * initial position (a normal %iterator into the container). */ insert_iterator(_Container& __x, typename _Container::iterator __i) : container(&__x), iter(__i) {} /** * @param value An instance of whatever type * container_type::const_reference is; presumably a * reference-to-const T for container<T>. * @return This %iterator, for chained operations. * * This kind of %iterator maintains its own position in the * container. Assigning a value to the %iterator will insert the * value into the container at the place before the %iterator. * * The position is maintained such that subsequent assignments will * insert values immediately after one another. For example, * @code * // vector v contains A and Z * * insert_iterator i (v, ++v.begin()); * i = 1; * i = 2; * i = 3; * * // vector v contains A, 1, 2, 3, and Z * @endcode */ insert_iterator& operator=(const typename _Container::const_reference __value) { iter = container->insert(iter, __value); ++iter; return *this; } /// Simply returns *this. insert_iterator& operator*() { return *this; } /// Simply returns *this. (This %iterator does not "move".) insert_iterator& operator++() { return *this; } /// Simply returns *this. (This %iterator does not "move".) insert_iterator& operator++(int) { return *this; } }; /** * @param x A container of arbitrary type. * @return An instance of insert_iterator working on @p x. * * This wrapper function helps in creating insert_iterator instances. * Typing the name of the %iterator requires knowing the precise full * type of the container, which can be tedious and impedes generic * programming. Using this function lets you take advantage of automatic * template parameter deduction, making the compiler match the correct * types for you. */ template<typename _Container, typename _Iterator> inline insert_iterator<_Container> inserter(_Container& __x, _Iterator __i) { return insert_iterator<_Container>(__x, typename _Container::iterator(__i)); } } // namespace std namespace __gnu_cxx { // This iterator adapter is 'normal' in the sense that it does not // change the semantics of any of the operators of its iterator // parameter. Its primary purpose is to convert an iterator that is // not a class, e.g. a pointer, into an iterator that is a class. // The _Container parameter exists solely so that different containers // using this template can instantiate different types, even if the // _Iterator parameter is the same. using std::iterator_traits; using std::iterator; template<typename _Iterator, typename _Container> class __normal_iterator { protected: _Iterator _M_current; public: typedef typename iterator_traits<_Iterator>::iterator_category iterator_category; typedef typename iterator_traits<_Iterator>::value_type value_type; typedef typename iterator_traits<_Iterator>::difference_type difference_type; typedef typename iterator_traits<_Iterator>::reference reference; typedef typename iterator_traits<_Iterator>::pointer pointer; __normal_iterator() : _M_current(_Iterator()) { } explicit __normal_iterator(const _Iterator& __i) : _M_current(__i) { } // Allow iterator to const_iterator conversion template<typename _Iter> inline __normal_iterator(const __normal_iterator<_Iter, _Container>& __i) : _M_current(__i.base()) { } // Forward iterator requirements reference operator*() const { return *_M_current; } pointer operator->() const { return _M_current; } __normal_iterator& operator++() { ++_M_current; return *this; } __normal_iterator operator++(int) { return __normal_iterator(_M_current++); } // Bidirectional iterator requirements __normal_iterator& operator--() { --_M_current; return *this; } __normal_iterator operator--(int) { return __normal_iterator(_M_current--); } // Random access iterator requirements reference operator[](const difference_type& __n) const { return _M_current[__n]; } __normal_iterator& operator+=(const difference_type& __n) { _M_current += __n; return *this; } __normal_iterator operator+(const difference_type& __n) const { return __normal_iterator(_M_current + __n); } __normal_iterator& operator-=(const difference_type& __n) { _M_current -= __n; return *this; } __normal_iterator operator-(const difference_type& __n) const { return __normal_iterator(_M_current - __n); } const _Iterator& base() const { return _M_current; } }; // Note: In what follows, the left- and right-hand-side iterators are // allowed to vary in types (conceptually in cv-qualification) so that // comparaison between cv-qualified and non-cv-qualified iterators be // valid. However, the greedy and unfriendly operators in std::rel_ops // will make overload resolution ambiguous (when in scope) if we don't // provide overloads whose operands are of the same type. Can someone // remind me what generic programming is about? -- Gaby // Forward iterator requirements template<typename _IteratorL, typename _IteratorR, typename _Container> inline bool operator==(const __normal_iterator<_IteratorL, _Container>& __lhs, const __normal_iterator<_IteratorR, _Container>& __rhs) { return __lhs.base() == __rhs.base(); } template<typename _Iterator, typename _Container> inline bool operator==(const __normal_iterator<_Iterator, _Container>& __lhs, const __normal_iterator<_Iterator, _Container>& __rhs) { return __lhs.base() == __rhs.base(); } template<typename _IteratorL, typename _IteratorR, typename _Container> inline bool operator!=(const __normal_iterator<_IteratorL, _Container>& __lhs, const __normal_iterator<_IteratorR, _Container>& __rhs) { return __lhs.base() != __rhs.base(); } template<typename _Iterator, typename _Container> inline bool operator!=(const __normal_iterator<_Iterator, _Container>& __lhs, const __normal_iterator<_Iterator, _Container>& __rhs) { return __lhs.base() != __rhs.base(); } // Random access iterator requirements template<typename _IteratorL, typename _IteratorR, typename _Container> inline bool operator<(const __normal_iterator<_IteratorL, _Container>& __lhs, const __normal_iterator<_IteratorR, _Container>& __rhs) { return __lhs.base() < __rhs.base(); } template<typename _Iterator, typename _Container> inline bool operator<(const __normal_iterator<_Iterator, _Container>& __lhs, const __normal_iterator<_Iterator, _Container>& __rhs) { return __lhs.base() < __rhs.base(); } template<typename _IteratorL, typename _IteratorR, typename _Container> inline bool operator>(const __normal_iterator<_IteratorL, _Container>& __lhs, const __normal_iterator<_IteratorR, _Container>& __rhs) { return __lhs.base() > __rhs.base(); } template<typename _Iterator, typename _Container> inline bool operator>(const __normal_iterator<_Iterator, _Container>& __lhs, const __normal_iterator<_Iterator, _Container>& __rhs) { return __lhs.base() > __rhs.base(); } template<typename _IteratorL, typename _IteratorR, typename _Container> inline bool operator<=(const __normal_iterator<_IteratorL, _Container>& __lhs, const __normal_iterator<_IteratorR, _Container>& __rhs) { return __lhs.base() <= __rhs.base(); } template<typename _Iterator, typename _Container> inline bool operator<=(const __normal_iterator<_Iterator, _Container>& __lhs, const __normal_iterator<_Iterator, _Container>& __rhs) { return __lhs.base() <= __rhs.base(); } template<typename _IteratorL, typename _IteratorR, typename _Container> inline bool operator>=(const __normal_iterator<_IteratorL, _Container>& __lhs, const __normal_iterator<_IteratorR, _Container>& __rhs) { return __lhs.base() >= __rhs.base(); } template<typename _Iterator, typename _Container> inline bool operator>=(const __normal_iterator<_Iterator, _Container>& __lhs, const __normal_iterator<_Iterator, _Container>& __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 _Container> inline typename __normal_iterator<_IteratorL, _Container>::difference_type operator-(const __normal_iterator<_IteratorL, _Container>& __lhs, const __normal_iterator<_IteratorR, _Container>& __rhs) { return __lhs.base() - __rhs.base(); } template<typename _Iterator, typename _Container> inline __normal_iterator<_Iterator, _Container> operator+(typename __normal_iterator<_Iterator, _Container>::difference_type __n, const __normal_iterator<_Iterator, _Container>& __i) { return __normal_iterator<_Iterator, _Container>(__i.base() + __n); } } // namespace __gnu_cxx #endif // Local Variables: // mode:C++ // End: