// Deque implementation -*- C++ -*- // Copyright (C) 2001, 2002, 2003, 2004, 2005 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) 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_deque.h * This is an internal header file, included by other library headers. * You should not attempt to use it directly. */ #ifndef _DEQUE_H #define _DEQUE_H 1 #include <bits/concept_check.h> #include <bits/stl_iterator_base_types.h> #include <bits/stl_iterator_base_funcs.h> namespace _GLIBCXX_STD { /** * @if maint * @brief This function controls the size of memory nodes. * @param size The size of an element. * @return The number (not byte size) of elements per node. * * This function started off as a compiler kludge from SGI, but seems to * be a useful wrapper around a repeated constant expression. The '512' is * tuneable (and no other code needs to change), but no investigation has * been done since inheriting the SGI code. * @endif */ inline size_t __deque_buf_size(size_t __size) { return __size < 512 ? size_t(512 / __size) : size_t(1); } /** * @brief A deque::iterator. * * Quite a bit of intelligence here. Much of the functionality of * deque is actually passed off to this class. A deque holds two * of these internally, marking its valid range. Access to * elements is done as offsets of either of those two, relying on * operator overloading in this class. * * @if maint * All the functions are op overloads except for _M_set_node. * @endif */ template<typename _Tp, typename _Ref, typename _Ptr> struct _Deque_iterator { typedef _Deque_iterator<_Tp, _Tp&, _Tp*> iterator; typedef _Deque_iterator<_Tp, const _Tp&, const _Tp*> const_iterator; static size_t _S_buffer_size() { return __deque_buf_size(sizeof(_Tp)); } typedef random_access_iterator_tag iterator_category; typedef _Tp value_type; typedef _Ptr pointer; typedef _Ref reference; typedef size_t size_type; typedef ptrdiff_t difference_type; typedef _Tp** _Map_pointer; typedef _Deque_iterator _Self; _Tp* _M_cur; _Tp* _M_first; _Tp* _M_last; _Map_pointer _M_node; _Deque_iterator(_Tp* __x, _Map_pointer __y) : _M_cur(__x), _M_first(*__y), _M_last(*__y + _S_buffer_size()), _M_node(__y) {} _Deque_iterator() : _M_cur(0), _M_first(0), _M_last(0), _M_node(0) {} _Deque_iterator(const iterator& __x) : _M_cur(__x._M_cur), _M_first(__x._M_first), _M_last(__x._M_last), _M_node(__x._M_node) {} reference operator*() const { return *_M_cur; } pointer operator->() const { return _M_cur; } _Self& operator++() { ++_M_cur; if (_M_cur == _M_last) { _M_set_node(_M_node + 1); _M_cur = _M_first; } return *this; } _Self operator++(int) { _Self __tmp = *this; ++*this; return __tmp; } _Self& operator--() { if (_M_cur == _M_first) { _M_set_node(_M_node - 1); _M_cur = _M_last; } --_M_cur; return *this; } _Self operator--(int) { _Self __tmp = *this; --*this; return __tmp; } _Self& operator+=(difference_type __n) { const difference_type __offset = __n + (_M_cur - _M_first); if (__offset >= 0 && __offset < difference_type(_S_buffer_size())) _M_cur += __n; else { const difference_type __node_offset = __offset > 0 ? __offset / difference_type(_S_buffer_size()) : -difference_type((-__offset - 1) / _S_buffer_size()) - 1; _M_set_node(_M_node + __node_offset); _M_cur = _M_first + (__offset - __node_offset * difference_type(_S_buffer_size())); } return *this; } _Self operator+(difference_type __n) const { _Self __tmp = *this; return __tmp += __n; } _Self& operator-=(difference_type __n) { return *this += -__n; } _Self operator-(difference_type __n) const { _Self __tmp = *this; return __tmp -= __n; } reference operator[](difference_type __n) const { return *(*this + __n); } /** @if maint * Prepares to traverse new_node. Sets everything except * _M_cur, which should therefore be set by the caller * immediately afterwards, based on _M_first and _M_last. * @endif */ void _M_set_node(_Map_pointer __new_node) { _M_node = __new_node; _M_first = *__new_node; _M_last = _M_first + difference_type(_S_buffer_size()); } }; // Note: we also provide overloads whose operands are of the same type in // order to avoid ambiguous overload resolution when std::rel_ops operators // are in scope (for additional details, see libstdc++/3628) template<typename _Tp, typename _Ref, typename _Ptr> inline bool operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x, const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) { return __x._M_cur == __y._M_cur; } template<typename _Tp, typename _RefL, typename _PtrL, typename _RefR, typename _PtrR> inline bool operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x, const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) { return __x._M_cur == __y._M_cur; } template<typename _Tp, typename _Ref, typename _Ptr> inline bool operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x, const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) { return !(__x == __y); } template<typename _Tp, typename _RefL, typename _PtrL, typename _RefR, typename _PtrR> inline bool operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x, const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) { return !(__x == __y); } template<typename _Tp, typename _Ref, typename _Ptr> inline bool operator<(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x, const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) { return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur) : (__x._M_node < __y._M_node); } template<typename _Tp, typename _RefL, typename _PtrL, typename _RefR, typename _PtrR> inline bool operator<(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x, const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) { return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur) : (__x._M_node < __y._M_node); } template<typename _Tp, typename _Ref, typename _Ptr> inline bool operator>(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x, const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) { return __y < __x; } template<typename _Tp, typename _RefL, typename _PtrL, typename _RefR, typename _PtrR> inline bool operator>(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x, const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) { return __y < __x; } template<typename _Tp, typename _Ref, typename _Ptr> inline bool operator<=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x, const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) { return !(__y < __x); } template<typename _Tp, typename _RefL, typename _PtrL, typename _RefR, typename _PtrR> inline bool operator<=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x, const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) { return !(__y < __x); } template<typename _Tp, typename _Ref, typename _Ptr> inline bool operator>=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x, const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) { return !(__x < __y); } template<typename _Tp, typename _RefL, typename _PtrL, typename _RefR, typename _PtrR> inline bool operator>=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x, const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) { return !(__x < __y); } // _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 _Tp, typename _RefL, typename _PtrL, typename _RefR, typename _PtrR> inline typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type operator-(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x, const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) { return typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type (_Deque_iterator<_Tp, _RefL, _PtrL>::_S_buffer_size()) * (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first) + (__y._M_last - __y._M_cur); } template<typename _Tp, typename _Ref, typename _Ptr> inline _Deque_iterator<_Tp, _Ref, _Ptr> operator+(ptrdiff_t __n, const _Deque_iterator<_Tp, _Ref, _Ptr>& __x) { return __x + __n; } /** * @if maint * Deque base class. This class provides the unified face for %deque's * allocation. This class's constructor and destructor allocate and * deallocate (but do not initialize) storage. This makes %exception * safety easier. * * Nothing in this class ever constructs or destroys an actual Tp element. * (Deque handles that itself.) Only/All memory management is performed * here. * @endif */ template<typename _Tp, typename _Alloc> class _Deque_base { public: typedef _Alloc allocator_type; allocator_type get_allocator() const { return *static_cast<const _Alloc*>(&this->_M_impl); } typedef _Deque_iterator<_Tp, _Tp&, _Tp*> iterator; typedef _Deque_iterator<_Tp, const _Tp&, const _Tp*> const_iterator; _Deque_base(const allocator_type& __a, size_t __num_elements) : _M_impl(__a) { _M_initialize_map(__num_elements); } _Deque_base(const allocator_type& __a) : _M_impl(__a) { } ~_Deque_base(); protected: //This struct encapsulates the implementation of the std::deque //standard container and at the same time makes use of the EBO //for empty allocators. struct _Deque_impl : public _Alloc { _Tp** _M_map; size_t _M_map_size; iterator _M_start; iterator _M_finish; _Deque_impl(const _Alloc& __a) : _Alloc(__a), _M_map(0), _M_map_size(0), _M_start(), _M_finish() { } }; typedef typename _Alloc::template rebind<_Tp*>::other _Map_alloc_type; _Map_alloc_type _M_get_map_allocator() const { return _Map_alloc_type(this->get_allocator()); } _Tp* _M_allocate_node() { return _M_impl._Alloc::allocate(__deque_buf_size(sizeof(_Tp))); } void _M_deallocate_node(_Tp* __p) { _M_impl._Alloc::deallocate(__p, __deque_buf_size(sizeof(_Tp))); } _Tp** _M_allocate_map(size_t __n) { return _M_get_map_allocator().allocate(__n); } void _M_deallocate_map(_Tp** __p, size_t __n) { _M_get_map_allocator().deallocate(__p, __n); } protected: void _M_initialize_map(size_t); void _M_create_nodes(_Tp** __nstart, _Tp** __nfinish); void _M_destroy_nodes(_Tp** __nstart, _Tp** __nfinish); enum { _S_initial_map_size = 8 }; _Deque_impl _M_impl; }; template<typename _Tp, typename _Alloc> _Deque_base<_Tp, _Alloc>:: ~_Deque_base() { if (this->_M_impl._M_map) { _M_destroy_nodes(this->_M_impl._M_start._M_node, this->_M_impl._M_finish._M_node + 1); _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size); } } /** * @if maint * @brief Layout storage. * @param num_elements The count of T's for which to allocate space * at first. * @return Nothing. * * The initial underlying memory layout is a bit complicated... * @endif */ template<typename _Tp, typename _Alloc> void _Deque_base<_Tp, _Alloc>:: _M_initialize_map(size_t __num_elements) { const size_t __num_nodes = (__num_elements/ __deque_buf_size(sizeof(_Tp)) + 1); this->_M_impl._M_map_size = std::max((size_t) _S_initial_map_size, size_t(__num_nodes + 2)); this->_M_impl._M_map = _M_allocate_map(this->_M_impl._M_map_size); // For "small" maps (needing less than _M_map_size nodes), allocation // starts in the middle elements and grows outwards. So nstart may be // the beginning of _M_map, but for small maps it may be as far in as // _M_map+3. _Tp** __nstart = (this->_M_impl._M_map + (this->_M_impl._M_map_size - __num_nodes) / 2); _Tp** __nfinish = __nstart + __num_nodes; try { _M_create_nodes(__nstart, __nfinish); } catch(...) { _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size); this->_M_impl._M_map = 0; this->_M_impl._M_map_size = 0; __throw_exception_again; } this->_M_impl._M_start._M_set_node(__nstart); this->_M_impl._M_finish._M_set_node(__nfinish - 1); this->_M_impl._M_start._M_cur = _M_impl._M_start._M_first; this->_M_impl._M_finish._M_cur = (this->_M_impl._M_finish._M_first + __num_elements % __deque_buf_size(sizeof(_Tp))); } template<typename _Tp, typename _Alloc> void _Deque_base<_Tp, _Alloc>:: _M_create_nodes(_Tp** __nstart, _Tp** __nfinish) { _Tp** __cur; try { for (__cur = __nstart; __cur < __nfinish; ++__cur) *__cur = this->_M_allocate_node(); } catch(...) { _M_destroy_nodes(__nstart, __cur); __throw_exception_again; } } template<typename _Tp, typename _Alloc> void _Deque_base<_Tp, _Alloc>:: _M_destroy_nodes(_Tp** __nstart, _Tp** __nfinish) { for (_Tp** __n = __nstart; __n < __nfinish; ++__n) _M_deallocate_node(*__n); } /** * @brief A standard container using fixed-size memory allocation and * constant-time manipulation of elements at either end. * * @ingroup Containers * @ingroup Sequences * * Meets the requirements of a <a href="tables.html#65">container</a>, a * <a href="tables.html#66">reversible container</a>, and a * <a href="tables.html#67">sequence</a>, including the * <a href="tables.html#68">optional sequence requirements</a>. * * In previous HP/SGI versions of deque, there was an extra template * parameter so users could control the node size. This extension turned * out to violate the C++ standard (it can be detected using template * template parameters), and it was removed. * * @if maint * Here's how a deque<Tp> manages memory. Each deque has 4 members: * * - Tp** _M_map * - size_t _M_map_size * - iterator _M_start, _M_finish * * map_size is at least 8. %map is an array of map_size * pointers-to-"nodes". (The name %map has nothing to do with the * std::map class, and "nodes" should not be confused with * std::list's usage of "node".) * * A "node" has no specific type name as such, but it is referred * to as "node" in this file. It is a simple array-of-Tp. If Tp * is very large, there will be one Tp element per node (i.e., an * "array" of one). For non-huge Tp's, node size is inversely * related to Tp size: the larger the Tp, the fewer Tp's will fit * in a node. The goal here is to keep the total size of a node * relatively small and constant over different Tp's, to improve * allocator efficiency. * * Not every pointer in the %map array will point to a node. If * the initial number of elements in the deque is small, the * /middle/ %map pointers will be valid, and the ones at the edges * will be unused. This same situation will arise as the %map * grows: available %map pointers, if any, will be on the ends. As * new nodes are created, only a subset of the %map's pointers need * to be copied "outward". * * Class invariants: * - For any nonsingular iterator i: * - i.node points to a member of the %map array. (Yes, you read that * correctly: i.node does not actually point to a node.) The member of * the %map array is what actually points to the node. * - i.first == *(i.node) (This points to the node (first Tp element).) * - i.last == i.first + node_size * - i.cur is a pointer in the range [i.first, i.last). NOTE: * the implication of this is that i.cur is always a dereferenceable * pointer, even if i is a past-the-end iterator. * - Start and Finish are always nonsingular iterators. NOTE: this * means that an empty deque must have one node, a deque with <N * elements (where N is the node buffer size) must have one node, a * deque with N through (2N-1) elements must have two nodes, etc. * - For every node other than start.node and finish.node, every * element in the node is an initialized object. If start.node == * finish.node, then [start.cur, finish.cur) are initialized * objects, and the elements outside that range are uninitialized * storage. Otherwise, [start.cur, start.last) and [finish.first, * finish.cur) are initialized objects, and [start.first, start.cur) * and [finish.cur, finish.last) are uninitialized storage. * - [%map, %map + map_size) is a valid, non-empty range. * - [start.node, finish.node] is a valid range contained within * [%map, %map + map_size). * - A pointer in the range [%map, %map + map_size) points to an allocated * node if and only if the pointer is in the range * [start.node, finish.node]. * * Here's the magic: nothing in deque is "aware" of the discontiguous * storage! * * The memory setup and layout occurs in the parent, _Base, and the iterator * class is entirely responsible for "leaping" from one node to the next. * All the implementation routines for deque itself work only through the * start and finish iterators. This keeps the routines simple and sane, * and we can use other standard algorithms as well. * @endif */ template<typename _Tp, typename _Alloc = allocator<_Tp> > class deque : protected _Deque_base<_Tp, _Alloc> { // concept requirements __glibcxx_class_requires(_Tp, _SGIAssignableConcept) typedef _Deque_base<_Tp, _Alloc> _Base; public: typedef _Tp value_type; typedef typename _Alloc::pointer pointer; typedef typename _Alloc::const_pointer const_pointer; typedef typename _Alloc::reference reference; typedef typename _Alloc::const_reference const_reference; typedef typename _Base::iterator iterator; typedef typename _Base::const_iterator const_iterator; typedef std::reverse_iterator<const_iterator> const_reverse_iterator; typedef std::reverse_iterator<iterator> reverse_iterator; typedef size_t size_type; typedef ptrdiff_t difference_type; typedef typename _Base::allocator_type allocator_type; protected: typedef pointer* _Map_pointer; static size_t _S_buffer_size() { return __deque_buf_size(sizeof(_Tp)); } // Functions controlling memory layout, and nothing else. using _Base::_M_initialize_map; using _Base::_M_create_nodes; using _Base::_M_destroy_nodes; using _Base::_M_allocate_node; using _Base::_M_deallocate_node; using _Base::_M_allocate_map; using _Base::_M_deallocate_map; /** @if maint * A total of four data members accumulated down the heirarchy. * May be accessed via _M_impl.* * @endif */ using _Base::_M_impl; public: // [23.2.1.1] construct/copy/destroy // (assign() and get_allocator() are also listed in this section) /** * @brief Default constructor creates no elements. */ explicit deque(const allocator_type& __a = allocator_type()) : _Base(__a, 0) {} /** * @brief Create a %deque 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 %deque with @a n copies of @a value. */ deque(size_type __n, const value_type& __value, const allocator_type& __a = allocator_type()) : _Base(__a, __n) { _M_fill_initialize(__value); } /** * @brief Create a %deque with default elements. * @param n The number of elements to initially create. * * This constructor fills the %deque with @a n copies of a * default-constructed element. */ explicit deque(size_type __n) : _Base(allocator_type(), __n) { _M_fill_initialize(value_type()); } /** * @brief %Deque copy constructor. * @param x A %deque of identical element and allocator types. * * The newly-created %deque uses a copy of the allocation object used * by @a x. */ deque(const deque& __x) : _Base(__x.get_allocator(), __x.size()) { std::__uninitialized_copy_a(__x.begin(), __x.end(), this->_M_impl._M_start, this->get_allocator()); } /** * @brief Builds a %deque from a range. * @param first An input iterator. * @param last An input iterator. * * Create a %deque consisting of copies of the elements from [first, * last). * * If the iterators are forward, bidirectional, or random-access, then * this will call the elements' copy constructor N times (where N is * distance(first,last)) and do no memory reallocation. But if only * input iterators are used, then this will do at most 2N calls to the * copy constructor, and logN memory reallocations. */ template<typename _InputIterator> deque(_InputIterator __first, _InputIterator __last, const allocator_type& __a = allocator_type()) : _Base(__a) { // Check whether it's an integral type. If so, it's not an iterator. typedef typename std::__is_integer<_InputIterator>::__type _Integral; _M_initialize_dispatch(__first, __last, _Integral()); } /** * 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. */ ~deque() { std::_Destroy(this->_M_impl._M_start, this->_M_impl._M_finish, this->get_allocator()); } /** * @brief %Deque assignment operator. * @param x A %deque 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. */ deque& operator=(const deque& __x); /** * @brief Assigns a given value to a %deque. * @param n Number of elements to be assigned. * @param val Value to be assigned. * * This function fills a %deque with @a n copies of the given * value. Note that the assignment completely changes the * %deque and that the resulting %deque'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 %deque. * @param first An input iterator. * @param last An input iterator. * * This function fills a %deque with copies of the elements in the * range [first,last). * * Note that the assignment completely changes the %deque and that the * resulting %deque's size is the same as the number of elements * assigned. Old data may be lost. */ template<typename _InputIterator> void assign(_InputIterator __first, _InputIterator __last) { typedef typename std::__is_integer<_InputIterator>::__type _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 * %deque. Iteration is done in ordinary element order. */ iterator begin() { return this->_M_impl._M_start; } /** * Returns a read-only (constant) iterator that points to the first * element in the %deque. Iteration is done in ordinary element order. */ const_iterator begin() const { return this->_M_impl._M_start; } /** * Returns a read/write iterator that points one past the last * element in the %deque. Iteration is done in ordinary * element order. */ iterator end() { return this->_M_impl._M_finish; } /** * Returns a read-only (constant) iterator that points one past * the last element in the %deque. Iteration is done in * ordinary element order. */ const_iterator end() const { return this->_M_impl._M_finish; } /** * Returns a read/write reverse iterator that points to the * last element in the %deque. Iteration is done in reverse * element order. */ reverse_iterator rbegin() { return reverse_iterator(this->_M_impl._M_finish); } /** * Returns a read-only (constant) reverse iterator that points * to the last element in the %deque. Iteration is done in * reverse element order. */ const_reverse_iterator rbegin() const { return const_reverse_iterator(this->_M_impl._M_finish); } /** * Returns a read/write reverse iterator that points to one * before the first element in the %deque. Iteration is done * in reverse element order. */ reverse_iterator rend() { return reverse_iterator(this->_M_impl._M_start); } /** * Returns a read-only (constant) reverse iterator that points * to one before the first element in the %deque. Iteration is * done in reverse element order. */ const_reverse_iterator rend() const { return const_reverse_iterator(this->_M_impl._M_start); } // [23.2.1.2] capacity /** Returns the number of elements in the %deque. */ size_type size() const { return this->_M_impl._M_finish - this->_M_impl._M_start; } /** Returns the size() of the largest possible %deque. */ size_type max_size() const { return size_type(-1); } /** * @brief Resizes the %deque to the specified number of elements. * @param new_size Number of elements the %deque should contain. * @param x Data with which new elements should be populated. * * This function will %resize the %deque to the specified * number of elements. If the number is smaller than the * %deque's current size the %deque is truncated, otherwise the * %deque is extended and new elements are populated with given * data. */ void resize(size_type __new_size, const value_type& __x) { const size_type __len = size(); if (__new_size < __len) erase(this->_M_impl._M_start + __new_size, this->_M_impl._M_finish); else insert(this->_M_impl._M_finish, __new_size - __len, __x); } /** * @brief Resizes the %deque to the specified number of elements. * @param new_size Number of elements the %deque should contain. * * This function will resize the %deque to the specified number * of elements. If the number is smaller than the %deque's * current size the %deque is truncated, otherwise the %deque * is extended and new elements are default-constructed. */ void resize(size_type new_size) { resize(new_size, value_type()); } /** * Returns true if the %deque is empty. (Thus begin() would * equal end().) */ bool empty() const { return this->_M_impl._M_finish == this->_M_impl._M_start; } // element access /** * @brief Subscript access to the data contained in the %deque. * @param n The index of the element for which data should be * accessed. * @return Read/write reference to data. * * This operator allows for easy, array-style, data access. * Note that data access with this operator is unchecked and * out_of_range lookups are not defined. (For checked lookups * see at().) */ reference operator[](size_type __n) { return this->_M_impl._M_start[difference_type(__n)]; } /** * @brief Subscript access to the data contained in the %deque. * @param n The index of the element for which data should be * accessed. * @return Read-only (constant) reference to data. * * This operator allows for easy, array-style, data access. * Note that data access with this operator is unchecked and * out_of_range lookups are not defined. (For checked lookups * see at().) */ const_reference operator[](size_type __n) const { return this->_M_impl._M_start[difference_type(__n)]; } protected: /// @if maint Safety check used only from at(). @endif void _M_range_check(size_type __n) const { if (__n >= this->size()) __throw_out_of_range(__N("deque::_M_range_check")); } public: /** * @brief Provides access to the data contained in the %deque. * @param n The index of the element for which data should be * accessed. * @return Read/write reference to data. * @throw std::out_of_range If @a n is an invalid index. * * This function provides for safer data access. The parameter * is first checked that it is in the range of the deque. The * function throws out_of_range if the check fails. */ reference at(size_type __n) { _M_range_check(__n); return (*this)[__n]; } /** * @brief Provides access to the data contained in the %deque. * @param n The index of the element for which data should be * accessed. * @return Read-only (constant) reference to data. * @throw std::out_of_range If @a n is an invalid index. * * This function provides for safer data access. The parameter is first * checked that it is in the range of the deque. The function throws * out_of_range if the check fails. */ const_reference at(size_type __n) const { _M_range_check(__n); return (*this)[__n]; } /** * Returns a read/write reference to the data at the first * element of the %deque. */ reference front() { return *begin(); } /** * Returns a read-only (constant) reference to the data at the first * element of the %deque. */ const_reference front() const { return *begin(); } /** * Returns a read/write reference to the data at the last element of the * %deque. */ reference back() { iterator __tmp = end(); --__tmp; return *__tmp; } /** * Returns a read-only (constant) reference to the data at the last * element of the %deque. */ const_reference back() const { const_iterator __tmp = end(); --__tmp; return *__tmp; } // [23.2.1.2] modifiers /** * @brief Add data to the front of the %deque. * @param x Data to be added. * * This is a typical stack operation. The function creates an * element at the front of the %deque and assigns the given * data to it. Due to the nature of a %deque this operation * can be done in constant time. */ void push_front(const value_type& __x) { if (this->_M_impl._M_start._M_cur != this->_M_impl._M_start._M_first) { this->_M_impl.construct(this->_M_impl._M_start._M_cur - 1, __x); --this->_M_impl._M_start._M_cur; } else _M_push_front_aux(__x); } /** * @brief Add data to the end of the %deque. * @param x Data to be added. * * This is a typical stack operation. The function creates an * element at the end of the %deque and assigns the given data * to it. Due to the nature of a %deque this operation can be * done in constant time. */ void push_back(const value_type& __x) { if (this->_M_impl._M_finish._M_cur != this->_M_impl._M_finish._M_last - 1) { this->_M_impl.construct(this->_M_impl._M_finish._M_cur, __x); ++this->_M_impl._M_finish._M_cur; } else _M_push_back_aux(__x); } /** * @brief Removes first element. * * This is a typical stack operation. It shrinks the %deque by one. * * 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() { if (this->_M_impl._M_start._M_cur != this->_M_impl._M_start._M_last - 1) { this->_M_impl.destroy(this->_M_impl._M_start._M_cur); ++this->_M_impl._M_start._M_cur; } else _M_pop_front_aux(); } /** * @brief Removes last element. * * This is a typical stack operation. It shrinks the %deque by one. * * 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() { if (this->_M_impl._M_finish._M_cur != this->_M_impl._M_finish._M_first) { --this->_M_impl._M_finish._M_cur; this->_M_impl.destroy(this->_M_impl._M_finish._M_cur); } else _M_pop_back_aux(); } /** * @brief Inserts given value into %deque before specified iterator. * @param position An iterator into the %deque. * @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. */ iterator insert(iterator position, const value_type& __x); /** * @brief Inserts a number of copies of given data into the %deque. * @param position An iterator into the %deque. * @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. */ void insert(iterator __position, size_type __n, const value_type& __x) { _M_fill_insert(__position, __n, __x); } /** * @brief Inserts a range into the %deque. * @param position An iterator into the %deque. * @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 %deque before the location specified * by @a pos. This is known as "range insert." */ template<typename _InputIterator> void insert(iterator __position, _InputIterator __first, _InputIterator __last) { // Check whether it's an integral type. If so, it's not an iterator. typedef typename std::__is_integer<_InputIterator>::__type _Integral; _M_insert_dispatch(__position, __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 %deque by one. * * The user is 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 %deque accordingly. * * The user is 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); /** * @brief Swaps data with another %deque. * @param x A %deque of the same element and allocator types. * * This exchanges the elements between two deques in constant time. * (Four pointers, so it should be quite fast.) * Note that the global std::swap() function is specialized such that * std::swap(d1,d2) will feed to this function. */ void swap(deque& __x) { std::swap(this->_M_impl._M_start, __x._M_impl._M_start); std::swap(this->_M_impl._M_finish, __x._M_impl._M_finish); std::swap(this->_M_impl._M_map, __x._M_impl._M_map); std::swap(this->_M_impl._M_map_size, __x._M_impl._M_map_size); } /** * 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(); protected: // Internal constructor functions follow. // called by the range constructor to implement [23.1.1]/9 template<typename _Integer> void _M_initialize_dispatch(_Integer __n, _Integer __x, __true_type) { _M_initialize_map(__n); _M_fill_initialize(__x); } // called by the range constructor to implement [23.1.1]/9 template<typename _InputIterator> void _M_initialize_dispatch(_InputIterator __first, _InputIterator __last, __false_type) { typedef typename iterator_traits<_InputIterator>::iterator_category _IterCategory; _M_range_initialize(__first, __last, _IterCategory()); } // called by the second initialize_dispatch above //@{ /** * @if maint * @brief Fills the deque with whatever is in [first,last). * @param first An input iterator. * @param last An input iterator. * @return Nothing. * * If the iterators are actually forward iterators (or better), then the * memory layout can be done all at once. Else we move forward using * push_back on each value from the iterator. * @endif */ template<typename _InputIterator> void _M_range_initialize(_InputIterator __first, _InputIterator __last, input_iterator_tag); // called by the second initialize_dispatch above template<typename _ForwardIterator> void _M_range_initialize(_ForwardIterator __first, _ForwardIterator __last, forward_iterator_tag); //@} /** * @if maint * @brief Fills the %deque with copies of value. * @param value Initial value. * @return Nothing. * @pre _M_start and _M_finish have already been initialized, * but none of the %deque's elements have yet been constructed. * * This function is called only when the user provides an explicit size * (with or without an explicit exemplar value). * @endif */ void _M_fill_initialize(const value_type& __value); // Internal assign functions follow. The *_aux functions do the actual // assignment work for the range versions. // called by the range assign to implement [23.1.1]/9 template<typename _Integer> void _M_assign_dispatch(_Integer __n, _Integer __val, __true_type) { _M_fill_assign(static_cast<size_type>(__n), static_cast<value_type>(__val)); } // called by the range assign to implement [23.1.1]/9 template<typename _InputIterator> void _M_assign_dispatch(_InputIterator __first, _InputIterator __last, __false_type) { typedef typename iterator_traits<_InputIterator>::iterator_category _IterCategory; _M_assign_aux(__first, __last, _IterCategory()); } // called by the second assign_dispatch above template<typename _InputIterator> void _M_assign_aux(_InputIterator __first, _InputIterator __last, input_iterator_tag); // called by the second assign_dispatch above template<typename _ForwardIterator> void _M_assign_aux(_ForwardIterator __first, _ForwardIterator __last, forward_iterator_tag) { const size_type __len = std::distance(__first, __last); if (__len > size()) { _ForwardIterator __mid = __first; std::advance(__mid, size()); std::copy(__first, __mid, begin()); insert(end(), __mid, __last); } else erase(std::copy(__first, __last, begin()), end()); } // 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) { if (__n > size()) { std::fill(begin(), end(), __val); insert(end(), __n - size(), __val); } else { erase(begin() + __n, end()); std::fill(begin(), end(), __val); } } //@{ /** * @if maint * @brief Helper functions for push_* and pop_*. * @endif */ void _M_push_back_aux(const value_type&); void _M_push_front_aux(const value_type&); void _M_pop_back_aux(); void _M_pop_front_aux(); //@} // Internal insert functions follow. The *_aux functions do the actual // insertion work when all shortcuts fail. // called by the range insert to implement [23.1.1]/9 template<typename _Integer> void _M_insert_dispatch(iterator __pos, _Integer __n, _Integer __x, __true_type) { _M_fill_insert(__pos, static_cast<size_type>(__n), static_cast<value_type>(__x)); } // called by the range insert to implement [23.1.1]/9 template<typename _InputIterator> void _M_insert_dispatch(iterator __pos, _InputIterator __first, _InputIterator __last, __false_type) { typedef typename iterator_traits<_InputIterator>::iterator_category _IterCategory; _M_range_insert_aux(__pos, __first, __last, _IterCategory()); } // called by the second insert_dispatch above template<typename _InputIterator> void _M_range_insert_aux(iterator __pos, _InputIterator __first, _InputIterator __last, input_iterator_tag); // called by the second insert_dispatch above template<typename _ForwardIterator> void _M_range_insert_aux(iterator __pos, _ForwardIterator __first, _ForwardIterator __last, forward_iterator_tag); // Called by insert(p,n,x), and the range insert when it turns out to be // the same thing. Can use fill functions in optimal situations, // otherwise passes off to insert_aux(p,n,x). void _M_fill_insert(iterator __pos, size_type __n, const value_type& __x); // called by insert(p,x) iterator _M_insert_aux(iterator __pos, const value_type& __x); // called by insert(p,n,x) via fill_insert void _M_insert_aux(iterator __pos, size_type __n, const value_type& __x); // called by range_insert_aux for forward iterators template<typename _ForwardIterator> void _M_insert_aux(iterator __pos, _ForwardIterator __first, _ForwardIterator __last, size_type __n); //@{ /** * @if maint * @brief Memory-handling helpers for the previous internal insert * functions. * @endif */ iterator _M_reserve_elements_at_front(size_type __n) { const size_type __vacancies = this->_M_impl._M_start._M_cur - this->_M_impl._M_start._M_first; if (__n > __vacancies) _M_new_elements_at_front(__n - __vacancies); return this->_M_impl._M_start - difference_type(__n); } iterator _M_reserve_elements_at_back(size_type __n) { const size_type __vacancies = (this->_M_impl._M_finish._M_last - this->_M_impl._M_finish._M_cur) - 1; if (__n > __vacancies) _M_new_elements_at_back(__n - __vacancies); return this->_M_impl._M_finish + difference_type(__n); } void _M_new_elements_at_front(size_type __new_elements); void _M_new_elements_at_back(size_type __new_elements); //@} //@{ /** * @if maint * @brief Memory-handling helpers for the major %map. * * Makes sure the _M_map has space for new nodes. Does not * actually add the nodes. Can invalidate _M_map pointers. * (And consequently, %deque iterators.) * @endif */ void _M_reserve_map_at_back (size_type __nodes_to_add = 1) { if (__nodes_to_add + 1 > this->_M_impl._M_map_size - (this->_M_impl._M_finish._M_node - this->_M_impl._M_map)) _M_reallocate_map(__nodes_to_add, false); } void _M_reserve_map_at_front (size_type __nodes_to_add = 1) { if (__nodes_to_add > size_type(this->_M_impl._M_start._M_node - this->_M_impl._M_map)) _M_reallocate_map(__nodes_to_add, true); } void _M_reallocate_map(size_type __nodes_to_add, bool __add_at_front); //@} }; /** * @brief Deque equality comparison. * @param x A %deque. * @param y A %deque of the same type as @a x. * @return True iff the size and elements of the deques are equal. * * This is an equivalence relation. It is linear in the size of the * deques. Deques are considered equivalent if their sizes are equal, * and if corresponding elements compare equal. */ template<typename _Tp, typename _Alloc> inline bool operator==(const deque<_Tp, _Alloc>& __x, const deque<_Tp, _Alloc>& __y) { return __x.size() == __y.size() && std::equal(__x.begin(), __x.end(), __y.begin()); } /** * @brief Deque ordering relation. * @param x A %deque. * @param y A %deque of the same type as @a x. * @return True iff @a x is lexicographically less than @a y. * * This is a total ordering relation. It is linear in the size of the * deques. The elements must be comparable with @c <. * * See std::lexicographical_compare() for how the determination is made. */ template<typename _Tp, typename _Alloc> inline bool operator<(const deque<_Tp, _Alloc>& __x, const deque<_Tp, _Alloc>& __y) { return lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end()); } /// Based on operator== template<typename _Tp, typename _Alloc> inline bool operator!=(const deque<_Tp, _Alloc>& __x, const deque<_Tp, _Alloc>& __y) { return !(__x == __y); } /// Based on operator< template<typename _Tp, typename _Alloc> inline bool operator>(const deque<_Tp, _Alloc>& __x, const deque<_Tp, _Alloc>& __y) { return __y < __x; } /// Based on operator< template<typename _Tp, typename _Alloc> inline bool operator<=(const deque<_Tp, _Alloc>& __x, const deque<_Tp, _Alloc>& __y) { return !(__y < __x); } /// Based on operator< template<typename _Tp, typename _Alloc> inline bool operator>=(const deque<_Tp, _Alloc>& __x, const deque<_Tp, _Alloc>& __y) { return !(__x < __y); } /// See std::deque::swap(). template<typename _Tp, typename _Alloc> inline void swap(deque<_Tp,_Alloc>& __x, deque<_Tp,_Alloc>& __y) { __x.swap(__y); } } // namespace std #endif /* _DEQUE_H */