1 // Deque implementation -*- C++ -*-
3 // Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc.
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 2, or (at your option)
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
16 // You should have received a copy of the GNU General Public License along
17 // with this library; see the file COPYING. If not, write to the Free
18 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
21 // As a special exception, you may use this file as part of a free software
22 // library without restriction. Specifically, if other files instantiate
23 // templates or use macros or inline functions from this file, or you compile
24 // this file and link it with other files to produce an executable, this
25 // file does not by itself cause the resulting executable to be covered by
26 // the GNU General Public License. This exception does not however
27 // invalidate any other reasons why the executable file might be covered by
28 // the GNU General Public License.
33 * Hewlett-Packard Company
35 * Permission to use, copy, modify, distribute and sell this software
36 * and its documentation for any purpose is hereby granted without fee,
37 * provided that the above copyright notice appear in all copies and
38 * that both that copyright notice and this permission notice appear
39 * in supporting documentation. Hewlett-Packard Company makes no
40 * representations about the suitability of this software for any
41 * purpose. It is provided "as is" without express or implied warranty.
45 * Silicon Graphics Computer Systems, Inc.
47 * Permission to use, copy, modify, distribute and sell this software
48 * and its documentation for any purpose is hereby granted without fee,
49 * provided that the above copyright notice appear in all copies and
50 * that both that copyright notice and this permission notice appear
51 * in supporting documentation. Silicon Graphics makes no
52 * representations about the suitability of this software for any
53 * purpose. It is provided "as is" without express or implied warranty.
57 * This is an internal header file, included by other library headers.
58 * You should not attempt to use it directly.
64 #include <bits/concept_check.h>
65 #include <bits/stl_iterator_base_types.h>
66 #include <bits/stl_iterator_base_funcs.h>
72 * @brief This function controls the size of memory nodes.
73 * @param size The size of an element.
74 * @return The number (not byte size) of elements per node.
76 * This function started off as a compiler kludge from SGI, but seems to
77 * be a useful wrapper around a repeated constant expression. The '512' is
78 * tuneable (and no other code needs to change), but no investigation has
79 * been done since inheriting the SGI code.
83 __deque_buf_size(size_t __size
)
84 { return __size
< 512 ? size_t(512 / __size
) : size_t(1); }
88 * @brief A deque::iterator.
90 * Quite a bit of intelligence here. Much of the functionality of deque is
91 * actually passed off to this class. A deque holds two of these internally,
92 * marking its valid range. Access to elements is done as offsets of either
93 * of those two, relying on operator overloading in this class.
96 * All the functions are op overloads except for _M_set_node.
99 template <typename _Tp
, typename _Ref
, typename _Ptr
>
100 struct _Deque_iterator
102 typedef _Deque_iterator
<_Tp
, _Tp
&, _Tp
*> iterator
;
103 typedef _Deque_iterator
<_Tp
, const _Tp
&, const _Tp
*> const_iterator
;
104 static size_t _S_buffer_size() { return __deque_buf_size(sizeof(_Tp
)); }
106 typedef random_access_iterator_tag iterator_category
;
107 typedef _Tp value_type
;
108 typedef _Ptr pointer
;
109 typedef _Ref reference
;
110 typedef size_t size_type
;
111 typedef ptrdiff_t difference_type
;
112 typedef _Tp
** _Map_pointer
;
113 typedef _Deque_iterator _Self
;
118 _Map_pointer _M_node
;
120 _Deque_iterator(_Tp
* __x
, _Map_pointer __y
)
121 : _M_cur(__x
), _M_first(*__y
),
122 _M_last(*__y
+ _S_buffer_size()), _M_node(__y
) {}
123 _Deque_iterator() : _M_cur(0), _M_first(0), _M_last(0), _M_node(0) {}
124 _Deque_iterator(const iterator
& __x
)
125 : _M_cur(__x
._M_cur
), _M_first(__x
._M_first
),
126 _M_last(__x
._M_last
), _M_node(__x
._M_node
) {}
128 reference
operator*() const { return *_M_cur
; }
129 pointer
operator->() const { return _M_cur
; }
131 _Self
& operator++() {
133 if (_M_cur
== _M_last
) {
134 _M_set_node(_M_node
+ 1);
139 _Self
operator++(int) {
145 _Self
& operator--() {
146 if (_M_cur
== _M_first
) {
147 _M_set_node(_M_node
- 1);
153 _Self
operator--(int) {
159 _Self
& operator+=(difference_type __n
)
161 difference_type __offset
= __n
+ (_M_cur
- _M_first
);
162 if (__offset
>= 0 && __offset
< difference_type(_S_buffer_size()))
165 difference_type __node_offset
=
166 __offset
> 0 ? __offset
/ difference_type(_S_buffer_size())
167 : -difference_type((-__offset
- 1) / _S_buffer_size()) - 1;
168 _M_set_node(_M_node
+ __node_offset
);
170 (__offset
- __node_offset
* difference_type(_S_buffer_size()));
175 _Self
operator+(difference_type __n
) const
181 _Self
& operator-=(difference_type __n
) { return *this += -__n
; }
183 _Self
operator-(difference_type __n
) const {
188 reference
operator[](difference_type __n
) const { return *(*this + __n
); }
191 * Prepares to traverse new_node. Sets everything except _M_cur, which
192 * should therefore be set by the caller immediately afterwards, based on
193 * _M_first and _M_last.
197 _M_set_node(_Map_pointer __new_node
)
199 _M_node
= __new_node
;
200 _M_first
= *__new_node
;
201 _M_last
= _M_first
+ difference_type(_S_buffer_size());
205 // Note: we also provide overloads whose operands are of the same type in
206 // order to avoid ambiguous overload resolution when std::rel_ops operators
207 // are in scope (for additional details, see libstdc++/3628)
208 template <typename _Tp
, typename _Ref
, typename _Ptr
>
210 operator==(const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __x
,
211 const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __y
)
213 return __x
._M_cur
== __y
._M_cur
;
216 template <typename _Tp
, typename _RefL
, typename _PtrL
,
217 typename _RefR
, typename _PtrR
>
219 operator==(const _Deque_iterator
<_Tp
, _RefL
, _PtrL
>& __x
,
220 const _Deque_iterator
<_Tp
, _RefR
, _PtrR
>& __y
)
222 return __x
._M_cur
== __y
._M_cur
;
225 template <typename _Tp
, typename _Ref
, typename _Ptr
>
227 operator!=(const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __x
,
228 const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __y
)
230 return !(__x
== __y
);
233 template <typename _Tp
, typename _RefL
, typename _PtrL
,
234 typename _RefR
, typename _PtrR
>
236 operator!=(const _Deque_iterator
<_Tp
, _RefL
, _PtrL
>& __x
,
237 const _Deque_iterator
<_Tp
, _RefR
, _PtrR
>& __y
)
239 return !(__x
== __y
);
242 template <typename _Tp
, typename _Ref
, typename _Ptr
>
244 operator<(const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __x
,
245 const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __y
)
247 return (__x
._M_node
== __y
._M_node
) ?
248 (__x
._M_cur
< __y
._M_cur
) : (__x
._M_node
< __y
._M_node
);
251 template <typename _Tp
, typename _RefL
, typename _PtrL
,
252 typename _RefR
, typename _PtrR
>
254 operator<(const _Deque_iterator
<_Tp
, _RefL
, _PtrL
>& __x
,
255 const _Deque_iterator
<_Tp
, _RefR
, _PtrR
>& __y
)
257 return (__x
._M_node
== __y
._M_node
) ?
258 (__x
._M_cur
< __y
._M_cur
) : (__x
._M_node
< __y
._M_node
);
261 template <typename _Tp
, typename _Ref
, typename _Ptr
>
263 operator>(const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __x
,
264 const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __y
)
269 template <typename _Tp
, typename _RefL
, typename _PtrL
,
270 typename _RefR
, typename _PtrR
>
272 operator>(const _Deque_iterator
<_Tp
, _RefL
, _PtrL
>& __x
,
273 const _Deque_iterator
<_Tp
, _RefR
, _PtrR
>& __y
)
278 template <typename _Tp
, typename _Ref
, typename _Ptr
>
280 operator<=(const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __x
,
281 const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __y
)
286 template <typename _Tp
, typename _RefL
, typename _PtrL
,
287 typename _RefR
, typename _PtrR
>
289 operator<=(const _Deque_iterator
<_Tp
, _RefL
, _PtrL
>& __x
,
290 const _Deque_iterator
<_Tp
, _RefR
, _PtrR
>& __y
)
295 template <typename _Tp
, typename _Ref
, typename _Ptr
>
297 operator>=(const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __x
,
298 const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __y
)
303 template <typename _Tp
, typename _RefL
, typename _PtrL
,
304 typename _RefR
, typename _PtrR
>
306 operator>=(const _Deque_iterator
<_Tp
, _RefL
, _PtrL
>& __x
,
307 const _Deque_iterator
<_Tp
, _RefR
, _PtrR
>& __y
)
312 // _GLIBCXX_RESOLVE_LIB_DEFECTS
313 // According to the resolution of DR179 not only the various comparison
314 // operators but also operator- must accept mixed iterator/const_iterator
316 template <typename _Tp
, typename _RefL
, typename _PtrL
,
317 typename _RefR
, typename _PtrR
>
318 inline typename _Deque_iterator
<_Tp
, _RefL
, _PtrL
>::difference_type
319 operator-(const _Deque_iterator
<_Tp
, _RefL
, _PtrL
>& __x
,
320 const _Deque_iterator
<_Tp
, _RefR
, _PtrR
>& __y
)
322 return typename _Deque_iterator
<_Tp
, _RefL
, _PtrL
>::difference_type
323 (_Deque_iterator
<_Tp
, _RefL
, _PtrL
>::_S_buffer_size()) *
324 (__x
._M_node
- __y
._M_node
- 1) + (__x
._M_cur
- __x
._M_first
) +
325 (__y
._M_last
- __y
._M_cur
);
328 template <typename _Tp
, typename _Ref
, typename _Ptr
>
329 inline _Deque_iterator
<_Tp
, _Ref
, _Ptr
>
330 operator+(ptrdiff_t __n
, const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __x
)
336 /// @if maint Primary default version. @endif
339 * Deque base class. It has two purposes. First, its constructor
340 * and destructor allocate (but don't initialize) storage. This makes
341 * %exception safety easier. Second, the base class encapsulates all of
342 * the differences between SGI-style allocators and standard-conforming
343 * allocators. (See allocator.h for more on this topic.) There are two
344 * versions: this ordinary one, and the space-saving specialization for
345 * instanceless allocators.
348 template <typename _Tp
, typename _Alloc
, bool __is_static
>
349 class _Deque_alloc_base
352 typedef typename _Alloc_traits
<_Tp
,_Alloc
>::allocator_type allocator_type
;
353 allocator_type
get_allocator() const { return _M_node_allocator
; }
355 _Deque_alloc_base(const allocator_type
& __a
)
356 : _M_node_allocator(__a
), _M_map_allocator(__a
),
357 _M_map(0), _M_map_size(0)
361 typedef typename _Alloc_traits
<_Tp
*, _Alloc
>::allocator_type
367 return _M_node_allocator
.allocate(__deque_buf_size(sizeof(_Tp
)));
371 _M_deallocate_node(_Tp
* __p
)
373 _M_node_allocator
.deallocate(__p
, __deque_buf_size(sizeof(_Tp
)));
377 _M_allocate_map(size_t __n
)
378 { return _M_map_allocator
.allocate(__n
); }
381 _M_deallocate_map(_Tp
** __p
, size_t __n
)
382 { _M_map_allocator
.deallocate(__p
, __n
); }
384 allocator_type _M_node_allocator
;
385 _Map_allocator_type _M_map_allocator
;
390 /// @if maint Specialization for instanceless allocators. @endif
391 template <typename _Tp
, typename _Alloc
>
392 class _Deque_alloc_base
<_Tp
, _Alloc
, true>
395 typedef typename _Alloc_traits
<_Tp
,_Alloc
>::allocator_type allocator_type
;
396 allocator_type
get_allocator() const { return allocator_type(); }
398 _Deque_alloc_base(const allocator_type
&)
399 : _M_map(0), _M_map_size(0)
403 typedef typename _Alloc_traits
<_Tp
,_Alloc
>::_Alloc_type _Node_alloc_type
;
404 typedef typename _Alloc_traits
<_Tp
*,_Alloc
>::_Alloc_type _Map_alloc_type
;
409 return _Node_alloc_type::allocate(__deque_buf_size(sizeof(_Tp
)));
413 _M_deallocate_node(_Tp
* __p
)
415 _Node_alloc_type::deallocate(__p
, __deque_buf_size(sizeof(_Tp
)));
419 _M_allocate_map(size_t __n
)
420 { return _Map_alloc_type::allocate(__n
); }
423 _M_deallocate_map(_Tp
** __p
, size_t __n
)
424 { _Map_alloc_type::deallocate(__p
, __n
); }
433 * Deque base class. Using _Alloc_traits in the instantiation of the parent
434 * class provides the compile-time dispatching mentioned in the parent's
435 * docs. This class provides the unified face for %deque's allocation.
437 * Nothing in this class ever constructs or destroys an actual Tp element.
438 * (Deque handles that itself.) Only/All memory management is performed
442 template <typename _Tp
, typename _Alloc
>
444 : public _Deque_alloc_base
<_Tp
,_Alloc
,
445 _Alloc_traits
<_Tp
, _Alloc
>::_S_instanceless
>
448 typedef _Deque_alloc_base
<_Tp
,_Alloc
,
449 _Alloc_traits
<_Tp
, _Alloc
>::_S_instanceless
>
451 typedef typename
_Base::allocator_type allocator_type
;
452 typedef _Deque_iterator
<_Tp
,_Tp
&,_Tp
*> iterator
;
453 typedef _Deque_iterator
<_Tp
,const _Tp
&,const _Tp
*> const_iterator
;
455 _Deque_base(const allocator_type
& __a
, size_t __num_elements
)
456 : _Base(__a
), _M_start(), _M_finish()
457 { _M_initialize_map(__num_elements
); }
458 _Deque_base(const allocator_type
& __a
)
459 : _Base(__a
), _M_start(), _M_finish() {}
463 void _M_initialize_map(size_t);
464 void _M_create_nodes(_Tp
** __nstart
, _Tp
** __nfinish
);
465 void _M_destroy_nodes(_Tp
** __nstart
, _Tp
** __nfinish
);
466 enum { _S_initial_map_size
= 8 };
473 template <typename _Tp
, typename _Alloc
>
474 _Deque_base
<_Tp
,_Alloc
>::~_Deque_base()
478 _M_destroy_nodes(_M_start
._M_node
, _M_finish
._M_node
+ 1);
479 _M_deallocate_map(this->_M_map
, this->_M_map_size
);
485 * @brief Layout storage.
486 * @param num_elements The count of T's for which to allocate space
490 * The initial underlying memory layout is a bit complicated...
493 template <typename _Tp
, typename _Alloc
>
495 _Deque_base
<_Tp
,_Alloc
>::_M_initialize_map(size_t __num_elements
)
498 __num_elements
/ __deque_buf_size(sizeof(_Tp
)) + 1;
501 = std::max((size_t) _S_initial_map_size
, __num_nodes
+ 2);
502 this->_M_map
= _M_allocate_map(this->_M_map_size
);
504 // For "small" maps (needing less than _M_map_size nodes), allocation
505 // starts in the middle elements and grows outwards. So nstart may be the
506 // beginning of _M_map, but for small maps it may be as far in as _M_map+3.
508 _Tp
** __nstart
= this->_M_map
+ (this->_M_map_size
- __num_nodes
) / 2;
509 _Tp
** __nfinish
= __nstart
+ __num_nodes
;
512 { _M_create_nodes(__nstart
, __nfinish
); }
515 _M_deallocate_map(this->_M_map
, this->_M_map_size
);
517 this->_M_map_size
= 0;
518 __throw_exception_again
;
521 _M_start
._M_set_node(__nstart
);
522 _M_finish
._M_set_node(__nfinish
- 1);
523 _M_start
._M_cur
= _M_start
._M_first
;
524 _M_finish
._M_cur
= _M_finish
._M_first
+
525 __num_elements
% __deque_buf_size(sizeof(_Tp
));
528 template <typename _Tp
, typename _Alloc
>
529 void _Deque_base
<_Tp
,_Alloc
>::_M_create_nodes(_Tp
** __nstart
, _Tp
** __nfinish
)
534 for (__cur
= __nstart
; __cur
< __nfinish
; ++__cur
)
535 *__cur
= _M_allocate_node();
539 _M_destroy_nodes(__nstart
, __cur
);
540 __throw_exception_again
;
544 template <typename _Tp
, typename _Alloc
>
546 _Deque_base
<_Tp
,_Alloc
>::_M_destroy_nodes(_Tp
** __nstart
, _Tp
** __nfinish
)
548 for (_Tp
** __n
= __nstart
; __n
< __nfinish
; ++__n
)
549 _M_deallocate_node(*__n
);
554 * @brief A standard container using fixed-size memory allocation and
555 * constant-time manipulation of elements at either end.
557 * @ingroup Containers
560 * Meets the requirements of a <a href="tables.html#65">container</a>, a
561 * <a href="tables.html#66">reversible container</a>, and a
562 * <a href="tables.html#67">sequence</a>, including the
563 * <a href="tables.html#68">optional sequence requirements</a>.
565 * In previous HP/SGI versions of deque, there was an extra template
566 * parameter so users could control the node size. This extension turned
567 * out to violate the C++ standard (it can be detected using template
568 * template parameters), and it was removed.
571 * Here's how a deque<Tp> manages memory. Each deque has 4 members:
574 * - size_t _M_map_size
575 * - iterator _M_start, _M_finish
577 * map_size is at least 8. %map is an array of map_size pointers-to-"nodes".
578 * (The name %map has nothing to do with the std::map class, and "nodes"
579 * should not be confused with std::list's usage of "node".)
581 * A "node" has no specific type name as such, but it is referred to as
582 * "node" in this file. It is a simple array-of-Tp. If Tp is very large,
583 * there will be one Tp element per node (i.e., an "array" of one).
584 * For non-huge Tp's, node size is inversely related to Tp size: the
585 * larger the Tp, the fewer Tp's will fit in a node. The goal here is to
586 * keep the total size of a node relatively small and constant over different
587 * Tp's, to improve allocator efficiency.
589 * **** As I write this, the nodes are /not/ allocated using the high-speed
590 * memory pool. There are 20 hours left in the year; perhaps I can fix
593 * Not every pointer in the %map array will point to a node. If the initial
594 * number of elements in the deque is small, the /middle/ %map pointers will
595 * be valid, and the ones at the edges will be unused. This same situation
596 * will arise as the %map grows: available %map pointers, if any, will be on
597 * the ends. As new nodes are created, only a subset of the %map's pointers
598 * need to be copied "outward".
601 * - For any nonsingular iterator i:
602 * - i.node points to a member of the %map array. (Yes, you read that
603 * correctly: i.node does not actually point to a node.) The member of
604 * the %map array is what actually points to the node.
605 * - i.first == *(i.node) (This points to the node (first Tp element).)
606 * - i.last == i.first + node_size
607 * - i.cur is a pointer in the range [i.first, i.last). NOTE:
608 * the implication of this is that i.cur is always a dereferenceable
609 * pointer, even if i is a past-the-end iterator.
610 * - Start and Finish are always nonsingular iterators. NOTE: this means that
611 * an empty deque must have one node, a deque with <N elements (where N is
612 * the node buffer size) must have one node, a deque with N through (2N-1)
613 * elements must have two nodes, etc.
614 * - For every node other than start.node and finish.node, every element in
615 * the node is an initialized object. If start.node == finish.node, then
616 * [start.cur, finish.cur) are initialized objects, and the elements outside
617 * that range are uninitialized storage. Otherwise, [start.cur, start.last)
618 * and [finish.first, finish.cur) are initialized objects, and [start.first,
619 * start.cur) and [finish.cur, finish.last) are uninitialized storage.
620 * - [%map, %map + map_size) is a valid, non-empty range.
621 * - [start.node, finish.node] is a valid range contained within
622 * [%map, %map + map_size).
623 * - A pointer in the range [%map, %map + map_size) points to an allocated
624 * node if and only if the pointer is in the range
625 * [start.node, finish.node].
627 * Here's the magic: nothing in deque is "aware" of the discontiguous
630 * The memory setup and layout occurs in the parent, _Base, and the iterator
631 * class is entirely responsible for "leaping" from one node to the next.
632 * All the implementation routines for deque itself work only through the
633 * start and finish iterators. This keeps the routines simple and sane,
634 * and we can use other standard algorithms as well.
637 template <typename _Tp
, typename _Alloc
= allocator
<_Tp
> >
638 class deque
: protected _Deque_base
<_Tp
, _Alloc
>
640 // concept requirements
641 __glibcxx_class_requires(_Tp
, _SGIAssignableConcept
)
643 typedef _Deque_base
<_Tp
, _Alloc
> _Base
;
646 typedef _Tp value_type
;
647 typedef value_type
* pointer
;
648 typedef const value_type
* const_pointer
;
649 typedef typename
_Base::iterator iterator
;
650 typedef typename
_Base::const_iterator const_iterator
;
651 typedef std::reverse_iterator
<const_iterator
> const_reverse_iterator
;
652 typedef std::reverse_iterator
<iterator
> reverse_iterator
;
653 typedef value_type
& reference
;
654 typedef const value_type
& const_reference
;
655 typedef size_t size_type
;
656 typedef ptrdiff_t difference_type
;
657 typedef typename
_Base::allocator_type allocator_type
;
660 typedef pointer
* _Map_pointer
;
661 static size_t _S_buffer_size() { return __deque_buf_size(sizeof(_Tp
)); }
663 // Functions controlling memory layout, and nothing else.
664 using _Base::_M_initialize_map
;
665 using _Base::_M_create_nodes
;
666 using _Base::_M_destroy_nodes
;
667 using _Base::_M_allocate_node
;
668 using _Base::_M_deallocate_node
;
669 using _Base::_M_allocate_map
;
670 using _Base::_M_deallocate_map
;
673 * A total of four data members accumulated down the heirarchy. If the
674 * _Alloc type requires separate instances, then two of them will also be
675 * included in each deque.
679 using _Base::_M_map_size
;
680 using _Base::_M_start
;
681 using _Base::_M_finish
;
684 // [23.2.1.1] construct/copy/destroy
685 // (assign() and get_allocator() are also listed in this section)
687 * @brief Default constructor creates no elements.
690 deque(const allocator_type
& __a
= allocator_type())
694 * @brief Create a %deque with copies of an exemplar element.
695 * @param n The number of elements to initially create.
696 * @param value An element to copy.
698 * This constructor fills the %deque with @a n copies of @a value.
700 deque(size_type __n
, const value_type
& __value
,
701 const allocator_type
& __a
= allocator_type())
703 { _M_fill_initialize(__value
); }
706 * @brief Create a %deque with default elements.
707 * @param n The number of elements to initially create.
709 * This constructor fills the %deque with @a n copies of a
710 * default-constructed element.
714 : _Base(allocator_type(), __n
)
715 { _M_fill_initialize(value_type()); }
718 * @brief %Deque copy constructor.
719 * @param x A %deque of identical element and allocator types.
721 * The newly-created %deque uses a copy of the allocation object used
724 deque(const deque
& __x
)
725 : _Base(__x
.get_allocator(), __x
.size())
726 { std::uninitialized_copy(__x
.begin(), __x
.end(), this->_M_start
); }
729 * @brief Builds a %deque from a range.
730 * @param first An input iterator.
731 * @param last An input iterator.
733 * Create a %deque consisting of copies of the elements from [first,last).
735 * If the iterators are forward, bidirectional, or random-access, then
736 * this will call the elements' copy constructor N times (where N is
737 * distance(first,last)) and do no memory reallocation. But if only
738 * input iterators are used, then this will do at most 2N calls to the
739 * copy constructor, and logN memory reallocations.
741 template<typename _InputIterator
>
742 deque(_InputIterator __first
, _InputIterator __last
,
743 const allocator_type
& __a
= allocator_type())
746 // Check whether it's an integral type. If so, it's not an iterator.
747 typedef typename _Is_integer
<_InputIterator
>::_Integral _Integral
;
748 _M_initialize_dispatch(__first
, __last
, _Integral());
752 * The dtor only erases the elements, and note that if the elements
753 * themselves are pointers, the pointed-to memory is not touched in any
754 * way. Managing the pointer is the user's responsibilty.
756 ~deque() { std::_Destroy(this->_M_start
, this->_M_finish
); }
759 * @brief %Deque assignment operator.
760 * @param x A %deque of identical element and allocator types.
762 * All the elements of @a x are copied, but unlike the copy constructor,
763 * the allocator object is not copied.
766 operator=(const deque
& __x
);
769 * @brief Assigns a given value to a %deque.
770 * @param n Number of elements to be assigned.
771 * @param val Value to be assigned.
773 * This function fills a %deque with @a n copies of the given value.
774 * Note that the assignment completely changes the %deque and that the
775 * resulting %deque's size is the same as the number of elements assigned.
776 * Old data may be lost.
779 assign(size_type __n
, const value_type
& __val
) { _M_fill_assign(__n
, __val
); }
782 * @brief Assigns a range to a %deque.
783 * @param first An input iterator.
784 * @param last An input iterator.
786 * This function fills a %deque with copies of the elements in the
787 * range [first,last).
789 * Note that the assignment completely changes the %deque and that the
790 * resulting %deque's size is the same as the number of elements assigned.
791 * Old data may be lost.
793 template<typename _InputIterator
>
795 assign(_InputIterator __first
, _InputIterator __last
)
797 typedef typename _Is_integer
<_InputIterator
>::_Integral _Integral
;
798 _M_assign_dispatch(__first
, __last
, _Integral());
801 /// Get a copy of the memory allocation object.
803 get_allocator() const { return _Base::get_allocator(); }
807 * Returns a read/write iterator that points to the first element in the
808 * %deque. Iteration is done in ordinary element order.
811 begin() { return this->_M_start
; }
814 * Returns a read-only (constant) iterator that points to the first element
815 * in the %deque. Iteration is done in ordinary element order.
818 begin() const { return this->_M_start
; }
821 * Returns a read/write iterator that points one past the last element in
822 * the %deque. Iteration is done in ordinary element order.
825 end() { return this->_M_finish
; }
828 * Returns a read-only (constant) iterator that points one past the last
829 * element in the %deque. Iteration is done in ordinary element order.
832 end() const { return this->_M_finish
; }
835 * Returns a read/write reverse iterator that points to the last element in
836 * the %deque. Iteration is done in reverse element order.
839 rbegin() { return reverse_iterator(this->_M_finish
); }
842 * Returns a read-only (constant) reverse iterator that points to the last
843 * element in the %deque. Iteration is done in reverse element order.
845 const_reverse_iterator
846 rbegin() const { return const_reverse_iterator(this->_M_finish
); }
849 * Returns a read/write reverse iterator that points to one before the
850 * first element in the %deque. Iteration is done in reverse element
854 rend() { return reverse_iterator(this->_M_start
); }
857 * Returns a read-only (constant) reverse iterator that points to one
858 * before the first element in the %deque. Iteration is done in reverse
861 const_reverse_iterator
862 rend() const { return const_reverse_iterator(this->_M_start
); }
864 // [23.2.1.2] capacity
865 /** Returns the number of elements in the %deque. */
867 size() const { return this->_M_finish
- this->_M_start
; }
869 /** Returns the size() of the largest possible %deque. */
871 max_size() const { return size_type(-1); }
874 * @brief Resizes the %deque to the specified number of elements.
875 * @param new_size Number of elements the %deque should contain.
876 * @param x Data with which new elements should be populated.
878 * This function will %resize the %deque to the specified number of
879 * elements. If the number is smaller than the %deque's current size the
880 * %deque is truncated, otherwise the %deque is extended and new elements
881 * are populated with given data.
884 resize(size_type __new_size
, const value_type
& __x
)
886 const size_type __len
= size();
887 if (__new_size
< __len
)
888 erase(this->_M_start
+ __new_size
, this->_M_finish
);
890 insert(this->_M_finish
, __new_size
- __len
, __x
);
894 * @brief Resizes the %deque to the specified number of elements.
895 * @param new_size Number of elements the %deque should contain.
897 * This function will resize the %deque to the specified number of
898 * elements. If the number is smaller than the %deque's current size the
899 * %deque is truncated, otherwise the %deque is extended and new elements
900 * are default-constructed.
903 resize(size_type new_size
) { resize(new_size
, value_type()); }
906 * Returns true if the %deque is empty. (Thus begin() would equal end().)
908 bool empty() const { return this->_M_finish
== this->_M_start
; }
912 * @brief Subscript access to the data contained in the %deque.
913 * @param n The index of the element for which data should be accessed.
914 * @return Read/write reference to data.
916 * This operator allows for easy, array-style, data access.
917 * Note that data access with this operator is unchecked and out_of_range
918 * lookups are not defined. (For checked lookups see at().)
921 operator[](size_type __n
) { return this->_M_start
[difference_type(__n
)]; }
924 * @brief Subscript access to the data contained in the %deque.
925 * @param n The index of the element for which data should be accessed.
926 * @return Read-only (constant) reference to data.
928 * This operator allows for easy, array-style, data access.
929 * Note that data access with this operator is unchecked and out_of_range
930 * lookups are not defined. (For checked lookups see at().)
933 operator[](size_type __n
) const {
934 return this->_M_start
[difference_type(__n
)];
938 /// @if maint Safety check used only from at(). @endif
940 _M_range_check(size_type __n
) const
942 if (__n
>= this->size())
943 __throw_out_of_range(__N("deque::_M_range_check"));
948 * @brief Provides access to the data contained in the %deque.
949 * @param n The index of the element for which data should be accessed.
950 * @return Read/write reference to data.
951 * @throw std::out_of_range If @a n is an invalid index.
953 * This function provides for safer data access. The parameter is first
954 * checked that it is in the range of the deque. The function throws
955 * out_of_range if the check fails.
958 at(size_type __n
) { _M_range_check(__n
); return (*this)[__n
]; }
961 * @brief Provides access to the data contained in the %deque.
962 * @param n The index of the element for which data should be accessed.
963 * @return Read-only (constant) reference to data.
964 * @throw std::out_of_range If @a n is an invalid index.
966 * This function provides for safer data access. The parameter is first
967 * checked that it is in the range of the deque. The function throws
968 * out_of_range if the check fails.
971 at(size_type __n
) const { _M_range_check(__n
); return (*this)[__n
]; }
974 * Returns a read/write reference to the data at the first element of the
978 front() { return *this->_M_start
; }
981 * Returns a read-only (constant) reference to the data at the first
982 * element of the %deque.
985 front() const { return *this->_M_start
; }
988 * Returns a read/write reference to the data at the last element of the
994 iterator __tmp
= this->_M_finish
;
1000 * Returns a read-only (constant) reference to the data at the last
1001 * element of the %deque.
1006 const_iterator __tmp
= this->_M_finish
;
1011 // [23.2.1.2] modifiers
1013 * @brief Add data to the front of the %deque.
1014 * @param x Data to be added.
1016 * This is a typical stack operation. The function creates an element at
1017 * the front of the %deque and assigns the given data to it. Due to the
1018 * nature of a %deque this operation can be done in constant time.
1021 push_front(const value_type
& __x
)
1023 if (this->_M_start
._M_cur
!= this->_M_start
._M_first
) {
1024 std::_Construct(this->_M_start
._M_cur
- 1, __x
);
1025 --this->_M_start
._M_cur
;
1028 _M_push_front_aux(__x
);
1032 * @brief Add data to the end of the %deque.
1033 * @param x Data to be added.
1035 * This is a typical stack operation. The function creates an element at
1036 * the end of the %deque and assigns the given data to it. Due to the
1037 * nature of a %deque this operation can be done in constant time.
1040 push_back(const value_type
& __x
)
1042 if (this->_M_finish
._M_cur
!= this->_M_finish
._M_last
- 1) {
1043 std::_Construct(this->_M_finish
._M_cur
, __x
);
1044 ++this->_M_finish
._M_cur
;
1047 _M_push_back_aux(__x
);
1051 * @brief Removes first element.
1053 * This is a typical stack operation. It shrinks the %deque by one.
1055 * Note that no data is returned, and if the first element's data is
1056 * needed, it should be retrieved before pop_front() is called.
1061 if (this->_M_start
._M_cur
!= this->_M_start
._M_last
- 1) {
1062 std::_Destroy(this->_M_start
._M_cur
);
1063 ++this->_M_start
._M_cur
;
1070 * @brief Removes last element.
1072 * This is a typical stack operation. It shrinks the %deque by one.
1074 * Note that no data is returned, and if the last element's data is
1075 * needed, it should be retrieved before pop_back() is called.
1080 if (this->_M_finish
._M_cur
!= this->_M_finish
._M_first
) {
1081 --this->_M_finish
._M_cur
;
1082 std::_Destroy(this->_M_finish
._M_cur
);
1089 * @brief Inserts given value into %deque before specified iterator.
1090 * @param position An iterator into the %deque.
1091 * @param x Data to be inserted.
1092 * @return An iterator that points to the inserted data.
1094 * This function will insert a copy of the given value before the specified
1098 insert(iterator position
, const value_type
& __x
);
1101 * @brief Inserts a number of copies of given data into the %deque.
1102 * @param position An iterator into the %deque.
1103 * @param n Number of elements to be inserted.
1104 * @param x Data to be inserted.
1106 * This function will insert a specified number of copies of the given data
1107 * before the location specified by @a position.
1110 insert(iterator __position
, size_type __n
, const value_type
& __x
)
1111 { _M_fill_insert(__position
, __n
, __x
); }
1114 * @brief Inserts a range into the %deque.
1115 * @param position An iterator into the %deque.
1116 * @param first An input iterator.
1117 * @param last An input iterator.
1119 * This function will insert copies of the data in the range [first,last)
1120 * into the %deque before the location specified by @a pos. This is
1121 * known as "range insert."
1123 template<typename _InputIterator
>
1125 insert(iterator __position
, _InputIterator __first
, _InputIterator __last
)
1127 // Check whether it's an integral type. If so, it's not an iterator.
1128 typedef typename _Is_integer
<_InputIterator
>::_Integral _Integral
;
1129 _M_insert_dispatch(__position
, __first
, __last
, _Integral());
1133 * @brief Remove element at given position.
1134 * @param position Iterator pointing to element to be erased.
1135 * @return An iterator pointing to the next element (or end()).
1137 * This function will erase the element at the given position and thus
1138 * shorten the %deque by one.
1140 * The user is cautioned that
1141 * this function only erases the element, and that if the element is itself
1142 * a pointer, the pointed-to memory is not touched in any way. Managing
1143 * the pointer is the user's responsibilty.
1146 erase(iterator __position
);
1149 * @brief Remove a range of elements.
1150 * @param first Iterator pointing to the first element to be erased.
1151 * @param last Iterator pointing to one past the last element to be
1153 * @return An iterator pointing to the element pointed to by @a last
1154 * prior to erasing (or end()).
1156 * This function will erase the elements in the range [first,last) and
1157 * shorten the %deque accordingly.
1159 * The user is cautioned that
1160 * this function only erases the elements, and that if the elements
1161 * themselves are pointers, the pointed-to memory is not touched in any
1162 * way. Managing the pointer is the user's responsibilty.
1165 erase(iterator __first
, iterator __last
);
1168 * @brief Swaps data with another %deque.
1169 * @param x A %deque of the same element and allocator types.
1171 * This exchanges the elements between two deques in constant time.
1172 * (Four pointers, so it should be quite fast.)
1173 * Note that the global std::swap() function is specialized such that
1174 * std::swap(d1,d2) will feed to this function.
1179 std::swap(this->_M_start
, __x
._M_start
);
1180 std::swap(this->_M_finish
, __x
._M_finish
);
1181 std::swap(this->_M_map
, __x
._M_map
);
1182 std::swap(this->_M_map_size
, __x
._M_map_size
);
1186 * Erases all the elements. Note that this function only erases the
1187 * elements, and that if the elements themselves are pointers, the
1188 * pointed-to memory is not touched in any way. Managing the pointer is
1189 * the user's responsibilty.
1194 // Internal constructor functions follow.
1196 // called by the range constructor to implement [23.1.1]/9
1197 template<typename _Integer
>
1199 _M_initialize_dispatch(_Integer __n
, _Integer __x
, __true_type
)
1201 _M_initialize_map(__n
);
1202 _M_fill_initialize(__x
);
1205 // called by the range constructor to implement [23.1.1]/9
1206 template<typename _InputIterator
>
1208 _M_initialize_dispatch(_InputIterator __first
, _InputIterator __last
,
1211 typedef typename iterator_traits
<_InputIterator
>::iterator_category
1213 _M_range_initialize(__first
, __last
, _IterCategory());
1216 // called by the second initialize_dispatch above
1220 * @brief Fills the deque with whatever is in [first,last).
1221 * @param first An input iterator.
1222 * @param last An input iterator.
1225 * If the iterators are actually forward iterators (or better), then the
1226 * memory layout can be done all at once. Else we move forward using
1227 * push_back on each value from the iterator.
1230 template <typename _InputIterator
>
1232 _M_range_initialize(_InputIterator __first
, _InputIterator __last
,
1233 input_iterator_tag
);
1235 // called by the second initialize_dispatch above
1236 template <typename _ForwardIterator
>
1238 _M_range_initialize(_ForwardIterator __first
, _ForwardIterator __last
,
1239 forward_iterator_tag
);
1244 * @brief Fills the %deque with copies of value.
1245 * @param value Initial value.
1247 * @pre _M_start and _M_finish have already been initialized, but none of
1248 * the %deque's elements have yet been constructed.
1250 * This function is called only when the user provides an explicit size
1251 * (with or without an explicit exemplar value).
1255 _M_fill_initialize(const value_type
& __value
);
1258 // Internal assign functions follow. The *_aux functions do the actual
1259 // assignment work for the range versions.
1261 // called by the range assign to implement [23.1.1]/9
1262 template<typename _Integer
>
1264 _M_assign_dispatch(_Integer __n
, _Integer __val
, __true_type
)
1266 _M_fill_assign(static_cast<size_type
>(__n
),
1267 static_cast<value_type
>(__val
));
1270 // called by the range assign to implement [23.1.1]/9
1271 template<typename _InputIterator
>
1273 _M_assign_dispatch(_InputIterator __first
, _InputIterator __last
, __false_type
)
1275 typedef typename iterator_traits
<_InputIterator
>::iterator_category
1277 _M_assign_aux(__first
, __last
, _IterCategory());
1280 // called by the second assign_dispatch above
1281 template <typename _InputIterator
>
1283 _M_assign_aux(_InputIterator __first
, _InputIterator __last
,
1284 input_iterator_tag
);
1286 // called by the second assign_dispatch above
1287 template <typename _ForwardIterator
>
1289 _M_assign_aux(_ForwardIterator __first
, _ForwardIterator __last
,
1290 forward_iterator_tag
)
1292 size_type __len
= std::distance(__first
, __last
);
1293 if (__len
> size()) {
1294 _ForwardIterator __mid
= __first
;
1295 std::advance(__mid
, size());
1296 std::copy(__first
, __mid
, begin());
1297 insert(end(), __mid
, __last
);
1300 erase(std::copy(__first
, __last
, begin()), end());
1303 // Called by assign(n,t), and the range assign when it turns out to be the
1306 _M_fill_assign(size_type __n
, const value_type
& __val
)
1310 std::fill(begin(), end(), __val
);
1311 insert(end(), __n
- size(), __val
);
1315 erase(begin() + __n
, end());
1316 std::fill(begin(), end(), __val
);
1324 * @brief Helper functions for push_* and pop_*.
1327 void _M_push_back_aux(const value_type
&);
1328 void _M_push_front_aux(const value_type
&);
1329 void _M_pop_back_aux();
1330 void _M_pop_front_aux();
1334 // Internal insert functions follow. The *_aux functions do the actual
1335 // insertion work when all shortcuts fail.
1337 // called by the range insert to implement [23.1.1]/9
1338 template<typename _Integer
>
1340 _M_insert_dispatch(iterator __pos
,
1341 _Integer __n
, _Integer __x
, __true_type
)
1343 _M_fill_insert(__pos
, static_cast<size_type
>(__n
),
1344 static_cast<value_type
>(__x
));
1347 // called by the range insert to implement [23.1.1]/9
1348 template<typename _InputIterator
>
1350 _M_insert_dispatch(iterator __pos
,
1351 _InputIterator __first
, _InputIterator __last
,
1354 typedef typename iterator_traits
<_InputIterator
>::iterator_category
1356 _M_range_insert_aux(__pos
, __first
, __last
, _IterCategory());
1359 // called by the second insert_dispatch above
1360 template <typename _InputIterator
>
1362 _M_range_insert_aux(iterator __pos
, _InputIterator __first
,
1363 _InputIterator __last
, input_iterator_tag
);
1365 // called by the second insert_dispatch above
1366 template <typename _ForwardIterator
>
1368 _M_range_insert_aux(iterator __pos
, _ForwardIterator __first
,
1369 _ForwardIterator __last
, forward_iterator_tag
);
1371 // Called by insert(p,n,x), and the range insert when it turns out to be
1372 // the same thing. Can use fill functions in optimal situations, otherwise
1373 // passes off to insert_aux(p,n,x).
1375 _M_fill_insert(iterator __pos
, size_type __n
, const value_type
& __x
);
1377 // called by insert(p,x)
1379 _M_insert_aux(iterator __pos
, const value_type
& __x
);
1381 // called by insert(p,n,x) via fill_insert
1383 _M_insert_aux(iterator __pos
, size_type __n
, const value_type
& __x
);
1385 // called by range_insert_aux for forward iterators
1386 template <typename _ForwardIterator
>
1388 _M_insert_aux(iterator __pos
,
1389 _ForwardIterator __first
, _ForwardIterator __last
,
1395 * @brief Memory-handling helpers for the previous internal insert
1400 _M_reserve_elements_at_front(size_type __n
)
1402 size_type __vacancies
= this->_M_start
._M_cur
- this->_M_start
._M_first
;
1403 if (__n
> __vacancies
)
1404 _M_new_elements_at_front(__n
- __vacancies
);
1405 return this->_M_start
- difference_type(__n
);
1409 _M_reserve_elements_at_back(size_type __n
)
1411 size_type __vacancies
1412 = (this->_M_finish
._M_last
- this->_M_finish
._M_cur
) - 1;
1413 if (__n
> __vacancies
)
1414 _M_new_elements_at_back(__n
- __vacancies
);
1415 return this->_M_finish
+ difference_type(__n
);
1419 _M_new_elements_at_front(size_type __new_elements
);
1422 _M_new_elements_at_back(size_type __new_elements
);
1429 * @brief Memory-handling helpers for the major %map.
1431 * Makes sure the _M_map has space for new nodes. Does not actually add
1432 * the nodes. Can invalidate _M_map pointers. (And consequently, %deque
1437 _M_reserve_map_at_back (size_type __nodes_to_add
= 1)
1439 if (__nodes_to_add
+ 1
1440 > this->_M_map_size
- (this->_M_finish
._M_node
- this->_M_map
))
1441 _M_reallocate_map(__nodes_to_add
, false);
1445 _M_reserve_map_at_front (size_type __nodes_to_add
= 1)
1447 if (__nodes_to_add
> size_type(this->_M_start
._M_node
- this->_M_map
))
1448 _M_reallocate_map(__nodes_to_add
, true);
1452 _M_reallocate_map(size_type __nodes_to_add
, bool __add_at_front
);
1458 * @brief Deque equality comparison.
1459 * @param x A %deque.
1460 * @param y A %deque of the same type as @a x.
1461 * @return True iff the size and elements of the deques are equal.
1463 * This is an equivalence relation. It is linear in the size of the
1464 * deques. Deques are considered equivalent if their sizes are equal,
1465 * and if corresponding elements compare equal.
1467 template <typename _Tp
, typename _Alloc
>
1468 inline bool operator==(const deque
<_Tp
, _Alloc
>& __x
,
1469 const deque
<_Tp
, _Alloc
>& __y
)
1471 return __x
.size() == __y
.size() &&
1472 std::equal(__x
.begin(), __x
.end(), __y
.begin());
1476 * @brief Deque ordering relation.
1477 * @param x A %deque.
1478 * @param y A %deque of the same type as @a x.
1479 * @return True iff @a x is lexicographically less than @a y.
1481 * This is a total ordering relation. It is linear in the size of the
1482 * deques. The elements must be comparable with @c <.
1484 * See std::lexicographical_compare() for how the determination is made.
1486 template <typename _Tp
, typename _Alloc
>
1487 inline bool operator<(const deque
<_Tp
, _Alloc
>& __x
,
1488 const deque
<_Tp
, _Alloc
>& __y
)
1490 return lexicographical_compare(__x
.begin(), __x
.end(),
1491 __y
.begin(), __y
.end());
1494 /// Based on operator==
1495 template <typename _Tp
, typename _Alloc
>
1496 inline bool operator!=(const deque
<_Tp
, _Alloc
>& __x
,
1497 const deque
<_Tp
, _Alloc
>& __y
) {
1498 return !(__x
== __y
);
1501 /// Based on operator<
1502 template <typename _Tp
, typename _Alloc
>
1503 inline bool operator>(const deque
<_Tp
, _Alloc
>& __x
,
1504 const deque
<_Tp
, _Alloc
>& __y
) {
1508 /// Based on operator<
1509 template <typename _Tp
, typename _Alloc
>
1510 inline bool operator<=(const deque
<_Tp
, _Alloc
>& __x
,
1511 const deque
<_Tp
, _Alloc
>& __y
) {
1512 return !(__y
< __x
);
1515 /// Based on operator<
1516 template <typename _Tp
, typename _Alloc
>
1517 inline bool operator>=(const deque
<_Tp
, _Alloc
>& __x
,
1518 const deque
<_Tp
, _Alloc
>& __y
) {
1519 return !(__x
< __y
);
1522 /// See std::deque::swap().
1523 template <typename _Tp
, typename _Alloc
>
1524 inline void swap(deque
<_Tp
,_Alloc
>& __x
, deque
<_Tp
,_Alloc
>& __y
)
1530 #endif /* _DEQUE_H */