1 // Deque implementation -*- C++ -*-
3 // Copyright (C) 2001, 2002, 2003, 2004 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>
68 namespace _GLIBCXX_STD
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
91 * deque is actually passed off to this class. A deque holds two
92 * of these internally, marking its valid range. Access to
93 * elements is done as offsets of either of those two, relying on
94 * operator overloading in this class.
97 * All the functions are op overloads except for _M_set_node.
100 template<typename _Tp
, typename _Ref
, typename _Ptr
>
101 struct _Deque_iterator
103 typedef _Deque_iterator
<_Tp
, _Tp
&, _Tp
*> iterator
;
104 typedef _Deque_iterator
<_Tp
, const _Tp
&, const _Tp
*> const_iterator
;
106 static size_t _S_buffer_size()
107 { return __deque_buf_size(sizeof(_Tp
)); }
109 typedef random_access_iterator_tag iterator_category
;
110 typedef _Tp value_type
;
111 typedef _Ptr pointer
;
112 typedef _Ref reference
;
113 typedef size_t size_type
;
114 typedef ptrdiff_t difference_type
;
115 typedef _Tp
** _Map_pointer
;
116 typedef _Deque_iterator _Self
;
121 _Map_pointer _M_node
;
123 _Deque_iterator(_Tp
* __x
, _Map_pointer __y
)
124 : _M_cur(__x
), _M_first(*__y
),
125 _M_last(*__y
+ _S_buffer_size()), _M_node(__y
) {}
127 _Deque_iterator() : _M_cur(0), _M_first(0), _M_last(0), _M_node(0) {}
129 _Deque_iterator(const iterator
& __x
)
130 : _M_cur(__x
._M_cur
), _M_first(__x
._M_first
),
131 _M_last(__x
._M_last
), _M_node(__x
._M_node
) {}
145 if (_M_cur
== _M_last
)
147 _M_set_node(_M_node
+ 1);
164 if (_M_cur
== _M_first
)
166 _M_set_node(_M_node
- 1);
182 operator+=(difference_type __n
)
184 const difference_type __offset
= __n
+ (_M_cur
- _M_first
);
185 if (__offset
>= 0 && __offset
< difference_type(_S_buffer_size()))
189 const difference_type __node_offset
=
190 __offset
> 0 ? __offset
/ difference_type(_S_buffer_size())
191 : -difference_type((-__offset
- 1)
192 / _S_buffer_size()) - 1;
193 _M_set_node(_M_node
+ __node_offset
);
194 _M_cur
= _M_first
+ (__offset
- __node_offset
195 * difference_type(_S_buffer_size()));
201 operator+(difference_type __n
) const
208 operator-=(difference_type __n
)
209 { return *this += -__n
; }
212 operator-(difference_type __n
) const
219 operator[](difference_type __n
) const
220 { return *(*this + __n
); }
223 * Prepares to traverse new_node. Sets everything except
224 * _M_cur, which should therefore be set by the caller
225 * immediately afterwards, based on _M_first and _M_last.
229 _M_set_node(_Map_pointer __new_node
)
231 _M_node
= __new_node
;
232 _M_first
= *__new_node
;
233 _M_last
= _M_first
+ difference_type(_S_buffer_size());
237 // Note: we also provide overloads whose operands are of the same type in
238 // order to avoid ambiguous overload resolution when std::rel_ops operators
239 // are in scope (for additional details, see libstdc++/3628)
240 template<typename _Tp
, typename _Ref
, typename _Ptr
>
242 operator==(const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __x
,
243 const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __y
)
244 { return __x
._M_cur
== __y
._M_cur
; }
246 template<typename _Tp
, typename _RefL
, typename _PtrL
,
247 typename _RefR
, typename _PtrR
>
249 operator==(const _Deque_iterator
<_Tp
, _RefL
, _PtrL
>& __x
,
250 const _Deque_iterator
<_Tp
, _RefR
, _PtrR
>& __y
)
251 { return __x
._M_cur
== __y
._M_cur
; }
253 template<typename _Tp
, typename _Ref
, typename _Ptr
>
255 operator!=(const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __x
,
256 const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __y
)
257 { return !(__x
== __y
); }
259 template<typename _Tp
, typename _RefL
, typename _PtrL
,
260 typename _RefR
, typename _PtrR
>
262 operator!=(const _Deque_iterator
<_Tp
, _RefL
, _PtrL
>& __x
,
263 const _Deque_iterator
<_Tp
, _RefR
, _PtrR
>& __y
)
264 { return !(__x
== __y
); }
266 template<typename _Tp
, typename _Ref
, typename _Ptr
>
268 operator<(const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __x
,
269 const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __y
)
270 { return (__x
._M_node
== __y
._M_node
) ? (__x
._M_cur
< __y
._M_cur
)
271 : (__x
._M_node
< __y
._M_node
); }
273 template<typename _Tp
, typename _RefL
, typename _PtrL
,
274 typename _RefR
, typename _PtrR
>
276 operator<(const _Deque_iterator
<_Tp
, _RefL
, _PtrL
>& __x
,
277 const _Deque_iterator
<_Tp
, _RefR
, _PtrR
>& __y
)
278 { return (__x
._M_node
== __y
._M_node
) ? (__x
._M_cur
< __y
._M_cur
)
279 : (__x
._M_node
< __y
._M_node
); }
281 template<typename _Tp
, typename _Ref
, typename _Ptr
>
283 operator>(const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __x
,
284 const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __y
)
285 { return __y
< __x
; }
287 template<typename _Tp
, typename _RefL
, typename _PtrL
,
288 typename _RefR
, typename _PtrR
>
290 operator>(const _Deque_iterator
<_Tp
, _RefL
, _PtrL
>& __x
,
291 const _Deque_iterator
<_Tp
, _RefR
, _PtrR
>& __y
)
292 { return __y
< __x
; }
294 template<typename _Tp
, typename _Ref
, typename _Ptr
>
296 operator<=(const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __x
,
297 const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __y
)
298 { return !(__y
< __x
); }
300 template<typename _Tp
, typename _RefL
, typename _PtrL
,
301 typename _RefR
, typename _PtrR
>
303 operator<=(const _Deque_iterator
<_Tp
, _RefL
, _PtrL
>& __x
,
304 const _Deque_iterator
<_Tp
, _RefR
, _PtrR
>& __y
)
305 { return !(__y
< __x
); }
307 template<typename _Tp
, typename _Ref
, typename _Ptr
>
309 operator>=(const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __x
,
310 const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __y
)
311 { return !(__x
< __y
); }
313 template<typename _Tp
, typename _RefL
, typename _PtrL
,
314 typename _RefR
, typename _PtrR
>
316 operator>=(const _Deque_iterator
<_Tp
, _RefL
, _PtrL
>& __x
,
317 const _Deque_iterator
<_Tp
, _RefR
, _PtrR
>& __y
)
318 { return !(__x
< __y
); }
320 // _GLIBCXX_RESOLVE_LIB_DEFECTS
321 // According to the resolution of DR179 not only the various comparison
322 // operators but also operator- must accept mixed iterator/const_iterator
324 template<typename _Tp
, typename _RefL
, typename _PtrL
,
325 typename _RefR
, typename _PtrR
>
326 inline typename _Deque_iterator
<_Tp
, _RefL
, _PtrL
>::difference_type
327 operator-(const _Deque_iterator
<_Tp
, _RefL
, _PtrL
>& __x
,
328 const _Deque_iterator
<_Tp
, _RefR
, _PtrR
>& __y
)
330 return typename _Deque_iterator
<_Tp
, _RefL
, _PtrL
>::difference_type
331 (_Deque_iterator
<_Tp
, _RefL
, _PtrL
>::_S_buffer_size())
332 * (__x
._M_node
- __y
._M_node
- 1) + (__x
._M_cur
- __x
._M_first
)
333 + (__y
._M_last
- __y
._M_cur
);
336 template<typename _Tp
, typename _Ref
, typename _Ptr
>
337 inline _Deque_iterator
<_Tp
, _Ref
, _Ptr
>
338 operator+(ptrdiff_t __n
, const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __x
)
339 { return __x
+ __n
; }
343 * Deque base class. This class provides the unified face for %deque's
344 * allocation. This class's constructor and destructor allocate and
345 * deallocate (but do not initialize) storage. This makes %exception
348 * Nothing in this class ever constructs or destroys an actual Tp element.
349 * (Deque handles that itself.) Only/All memory management is performed
353 template<typename _Tp
, typename _Alloc
>
357 typedef _Alloc allocator_type
;
360 get_allocator() const
361 { return *static_cast<const _Alloc
*>(&this->_M_impl
); }
363 typedef _Deque_iterator
<_Tp
, _Tp
&, _Tp
*> iterator
;
364 typedef _Deque_iterator
<_Tp
, const _Tp
&, const _Tp
*> const_iterator
;
366 _Deque_base(const allocator_type
& __a
, size_t __num_elements
)
368 { _M_initialize_map(__num_elements
); }
370 _Deque_base(const allocator_type
& __a
)
377 //This struct encapsulates the implementation of the std::deque
378 //standard container and at the same time makes use of the EBO
379 //for empty allocators.
388 _Deque_impl(const _Alloc
& __a
)
389 : _Alloc(__a
), _M_map(0), _M_map_size(0), _M_start(), _M_finish()
393 typedef typename
_Alloc::template rebind
<_Tp
*>::other _Map_alloc_type
;
394 _Map_alloc_type
_M_get_map_allocator() const
395 { return _Map_alloc_type(this->get_allocator()); }
399 { return _M_impl
._Alloc::allocate(__deque_buf_size(sizeof(_Tp
))); }
402 _M_deallocate_node(_Tp
* __p
)
403 { _M_impl
._Alloc::deallocate(__p
, __deque_buf_size(sizeof(_Tp
))); }
406 _M_allocate_map(size_t __n
)
407 { return _M_get_map_allocator().allocate(__n
); }
410 _M_deallocate_map(_Tp
** __p
, size_t __n
)
411 { _M_get_map_allocator().deallocate(__p
, __n
); }
414 void _M_initialize_map(size_t);
415 void _M_create_nodes(_Tp
** __nstart
, _Tp
** __nfinish
);
416 void _M_destroy_nodes(_Tp
** __nstart
, _Tp
** __nfinish
);
417 enum { _S_initial_map_size
= 8 };
422 template<typename _Tp
, typename _Alloc
>
423 _Deque_base
<_Tp
, _Alloc
>::
426 if (this->_M_impl
._M_map
)
428 _M_destroy_nodes(this->_M_impl
._M_start
._M_node
,
429 this->_M_impl
._M_finish
._M_node
+ 1);
430 _M_deallocate_map(this->_M_impl
._M_map
, this->_M_impl
._M_map_size
);
436 * @brief Layout storage.
437 * @param num_elements The count of T's for which to allocate space
441 * The initial underlying memory layout is a bit complicated...
444 template<typename _Tp
, typename _Alloc
>
446 _Deque_base
<_Tp
, _Alloc
>::
447 _M_initialize_map(size_t __num_elements
)
449 const size_t __num_nodes
= (__num_elements
/ __deque_buf_size(sizeof(_Tp
))
452 this->_M_impl
._M_map_size
= std::max((size_t) _S_initial_map_size
,
453 size_t(__num_nodes
+ 2));
454 this->_M_impl
._M_map
= _M_allocate_map(this->_M_impl
._M_map_size
);
456 // For "small" maps (needing less than _M_map_size nodes), allocation
457 // starts in the middle elements and grows outwards. So nstart may be
458 // the beginning of _M_map, but for small maps it may be as far in as
461 _Tp
** __nstart
= (this->_M_impl
._M_map
462 + (this->_M_impl
._M_map_size
- __num_nodes
) / 2);
463 _Tp
** __nfinish
= __nstart
+ __num_nodes
;
466 { _M_create_nodes(__nstart
, __nfinish
); }
469 _M_deallocate_map(this->_M_impl
._M_map
, this->_M_impl
._M_map_size
);
470 this->_M_impl
._M_map
= 0;
471 this->_M_impl
._M_map_size
= 0;
472 __throw_exception_again
;
475 this->_M_impl
._M_start
._M_set_node(__nstart
);
476 this->_M_impl
._M_finish
._M_set_node(__nfinish
- 1);
477 this->_M_impl
._M_start
._M_cur
= _M_impl
._M_start
._M_first
;
478 this->_M_impl
._M_finish
._M_cur
= (this->_M_impl
._M_finish
._M_first
480 % __deque_buf_size(sizeof(_Tp
)));
483 template<typename _Tp
, typename _Alloc
>
485 _Deque_base
<_Tp
, _Alloc
>::
486 _M_create_nodes(_Tp
** __nstart
, _Tp
** __nfinish
)
491 for (__cur
= __nstart
; __cur
< __nfinish
; ++__cur
)
492 *__cur
= this->_M_allocate_node();
496 _M_destroy_nodes(__nstart
, __cur
);
497 __throw_exception_again
;
501 template<typename _Tp
, typename _Alloc
>
503 _Deque_base
<_Tp
, _Alloc
>::
504 _M_destroy_nodes(_Tp
** __nstart
, _Tp
** __nfinish
)
506 for (_Tp
** __n
= __nstart
; __n
< __nfinish
; ++__n
)
507 _M_deallocate_node(*__n
);
511 * @brief A standard container using fixed-size memory allocation and
512 * constant-time manipulation of elements at either end.
514 * @ingroup Containers
517 * Meets the requirements of a <a href="tables.html#65">container</a>, a
518 * <a href="tables.html#66">reversible container</a>, and a
519 * <a href="tables.html#67">sequence</a>, including the
520 * <a href="tables.html#68">optional sequence requirements</a>.
522 * In previous HP/SGI versions of deque, there was an extra template
523 * parameter so users could control the node size. This extension turned
524 * out to violate the C++ standard (it can be detected using template
525 * template parameters), and it was removed.
528 * Here's how a deque<Tp> manages memory. Each deque has 4 members:
531 * - size_t _M_map_size
532 * - iterator _M_start, _M_finish
534 * map_size is at least 8. %map is an array of map_size
535 * pointers-to-"nodes". (The name %map has nothing to do with the
536 * std::map class, and "nodes" should not be confused with
537 * std::list's usage of "node".)
539 * A "node" has no specific type name as such, but it is referred
540 * to as "node" in this file. It is a simple array-of-Tp. If Tp
541 * is very large, there will be one Tp element per node (i.e., an
542 * "array" of one). For non-huge Tp's, node size is inversely
543 * related to Tp size: the larger the Tp, the fewer Tp's will fit
544 * in a node. The goal here is to keep the total size of a node
545 * relatively small and constant over different Tp's, to improve
546 * allocator efficiency.
548 * Not every pointer in the %map array will point to a node. If
549 * the initial number of elements in the deque is small, the
550 * /middle/ %map pointers will be valid, and the ones at the edges
551 * will be unused. This same situation will arise as the %map
552 * grows: available %map pointers, if any, will be on the ends. As
553 * new nodes are created, only a subset of the %map's pointers need
554 * to be copied "outward".
557 * - For any nonsingular iterator i:
558 * - i.node points to a member of the %map array. (Yes, you read that
559 * correctly: i.node does not actually point to a node.) The member of
560 * the %map array is what actually points to the node.
561 * - i.first == *(i.node) (This points to the node (first Tp element).)
562 * - i.last == i.first + node_size
563 * - i.cur is a pointer in the range [i.first, i.last). NOTE:
564 * the implication of this is that i.cur is always a dereferenceable
565 * pointer, even if i is a past-the-end iterator.
566 * - Start and Finish are always nonsingular iterators. NOTE: this
567 * means that an empty deque must have one node, a deque with <N
568 * elements (where N is the node buffer size) must have one node, a
569 * deque with N through (2N-1) elements must have two nodes, etc.
570 * - For every node other than start.node and finish.node, every
571 * element in the node is an initialized object. If start.node ==
572 * finish.node, then [start.cur, finish.cur) are initialized
573 * objects, and the elements outside that range are uninitialized
574 * storage. Otherwise, [start.cur, start.last) and [finish.first,
575 * finish.cur) are initialized objects, and [start.first, start.cur)
576 * and [finish.cur, finish.last) are uninitialized storage.
577 * - [%map, %map + map_size) is a valid, non-empty range.
578 * - [start.node, finish.node] is a valid range contained within
579 * [%map, %map + map_size).
580 * - A pointer in the range [%map, %map + map_size) points to an allocated
581 * node if and only if the pointer is in the range
582 * [start.node, finish.node].
584 * Here's the magic: nothing in deque is "aware" of the discontiguous
587 * The memory setup and layout occurs in the parent, _Base, and the iterator
588 * class is entirely responsible for "leaping" from one node to the next.
589 * All the implementation routines for deque itself work only through the
590 * start and finish iterators. This keeps the routines simple and sane,
591 * and we can use other standard algorithms as well.
594 template<typename _Tp
, typename _Alloc
= allocator
<_Tp
> >
595 class deque
: protected _Deque_base
<_Tp
, _Alloc
>
597 // concept requirements
598 __glibcxx_class_requires(_Tp
, _SGIAssignableConcept
)
600 typedef _Deque_base
<_Tp
, _Alloc
> _Base
;
603 typedef _Tp value_type
;
604 typedef typename
_Alloc::pointer pointer
;
605 typedef typename
_Alloc::const_pointer const_pointer
;
606 typedef typename
_Alloc::reference reference
;
607 typedef typename
_Alloc::const_reference const_reference
;
608 typedef typename
_Base::iterator iterator
;
609 typedef typename
_Base::const_iterator const_iterator
;
610 typedef std::reverse_iterator
<const_iterator
> const_reverse_iterator
;
611 typedef std::reverse_iterator
<iterator
> reverse_iterator
;
612 typedef size_t size_type
;
613 typedef ptrdiff_t difference_type
;
614 typedef typename
_Base::allocator_type allocator_type
;
617 typedef pointer
* _Map_pointer
;
619 static size_t _S_buffer_size()
620 { return __deque_buf_size(sizeof(_Tp
)); }
622 // Functions controlling memory layout, and nothing else.
623 using _Base::_M_initialize_map
;
624 using _Base::_M_create_nodes
;
625 using _Base::_M_destroy_nodes
;
626 using _Base::_M_allocate_node
;
627 using _Base::_M_deallocate_node
;
628 using _Base::_M_allocate_map
;
629 using _Base::_M_deallocate_map
;
632 * A total of four data members accumulated down the heirarchy.
633 * May be accessed via _M_impl.*
636 using _Base::_M_impl
;
639 // [23.2.1.1] construct/copy/destroy
640 // (assign() and get_allocator() are also listed in this section)
642 * @brief Default constructor creates no elements.
645 deque(const allocator_type
& __a
= allocator_type())
649 * @brief Create a %deque with copies of an exemplar element.
650 * @param n The number of elements to initially create.
651 * @param value An element to copy.
653 * This constructor fills the %deque with @a n copies of @a value.
655 deque(size_type __n
, const value_type
& __value
,
656 const allocator_type
& __a
= allocator_type())
658 { _M_fill_initialize(__value
); }
661 * @brief Create a %deque with default elements.
662 * @param n The number of elements to initially create.
664 * This constructor fills the %deque with @a n copies of a
665 * default-constructed element.
669 : _Base(allocator_type(), __n
)
670 { _M_fill_initialize(value_type()); }
673 * @brief %Deque copy constructor.
674 * @param x A %deque of identical element and allocator types.
676 * The newly-created %deque uses a copy of the allocation object used
679 deque(const deque
& __x
)
680 : _Base(__x
.get_allocator(), __x
.size())
681 { std::__uninitialized_copy_a(__x
.begin(), __x
.end(),
682 this->_M_impl
._M_start
,
683 this->get_allocator()); }
686 * @brief Builds a %deque from a range.
687 * @param first An input iterator.
688 * @param last An input iterator.
690 * Create a %deque consisting of copies of the elements from [first,
693 * If the iterators are forward, bidirectional, or random-access, then
694 * this will call the elements' copy constructor N times (where N is
695 * distance(first,last)) and do no memory reallocation. But if only
696 * input iterators are used, then this will do at most 2N calls to the
697 * copy constructor, and logN memory reallocations.
699 template<typename _InputIterator
>
700 deque(_InputIterator __first
, _InputIterator __last
,
701 const allocator_type
& __a
= allocator_type())
704 // Check whether it's an integral type. If so, it's not an iterator.
705 typedef typename _Is_integer
<_InputIterator
>::_Integral _Integral
;
706 _M_initialize_dispatch(__first
, __last
, _Integral());
710 * The dtor only erases the elements, and note that if the elements
711 * themselves are pointers, the pointed-to memory is not touched in any
712 * way. Managing the pointer is the user's responsibilty.
715 { std::_Destroy(this->_M_impl
._M_start
, this->_M_impl
._M_finish
,
716 this->get_allocator()); }
719 * @brief %Deque assignment operator.
720 * @param x A %deque of identical element and allocator types.
722 * All the elements of @a x are copied, but unlike the copy constructor,
723 * the allocator object is not copied.
726 operator=(const deque
& __x
);
729 * @brief Assigns a given value to a %deque.
730 * @param n Number of elements to be assigned.
731 * @param val Value to be assigned.
733 * This function fills a %deque with @a n copies of the given
734 * value. Note that the assignment completely changes the
735 * %deque and that the resulting %deque's size is the same as
736 * the number of elements assigned. Old data may be lost.
739 assign(size_type __n
, const value_type
& __val
)
740 { _M_fill_assign(__n
, __val
); }
743 * @brief Assigns a range to a %deque.
744 * @param first An input iterator.
745 * @param last An input iterator.
747 * This function fills a %deque with copies of the elements in the
748 * range [first,last).
750 * Note that the assignment completely changes the %deque and that the
751 * resulting %deque's size is the same as the number of elements
752 * assigned. Old data may be lost.
754 template<typename _InputIterator
>
756 assign(_InputIterator __first
, _InputIterator __last
)
758 typedef typename _Is_integer
<_InputIterator
>::_Integral _Integral
;
759 _M_assign_dispatch(__first
, __last
, _Integral());
762 /// Get a copy of the memory allocation object.
764 get_allocator() const
765 { return _Base::get_allocator(); }
769 * Returns a read/write iterator that points to the first element in the
770 * %deque. Iteration is done in ordinary element order.
774 { return this->_M_impl
._M_start
; }
777 * Returns a read-only (constant) iterator that points to the first
778 * element in the %deque. Iteration is done in ordinary element order.
782 { return this->_M_impl
._M_start
; }
785 * Returns a read/write iterator that points one past the last
786 * element in the %deque. Iteration is done in ordinary
791 { return this->_M_impl
._M_finish
; }
794 * Returns a read-only (constant) iterator that points one past
795 * the last element in the %deque. Iteration is done in
796 * ordinary element order.
800 { return this->_M_impl
._M_finish
; }
803 * Returns a read/write reverse iterator that points to the
804 * last element in the %deque. Iteration is done in reverse
809 { return reverse_iterator(this->_M_impl
._M_finish
); }
812 * Returns a read-only (constant) reverse iterator that points
813 * to the last element in the %deque. Iteration is done in
814 * reverse element order.
816 const_reverse_iterator
818 { return const_reverse_iterator(this->_M_impl
._M_finish
); }
821 * Returns a read/write reverse iterator that points to one
822 * before the first element in the %deque. Iteration is done
823 * in reverse element order.
826 rend() { return reverse_iterator(this->_M_impl
._M_start
); }
829 * Returns a read-only (constant) reverse iterator that points
830 * to one before the first element in the %deque. Iteration is
831 * done in reverse element order.
833 const_reverse_iterator
835 { return const_reverse_iterator(this->_M_impl
._M_start
); }
837 // [23.2.1.2] capacity
838 /** Returns the number of elements in the %deque. */
841 { return this->_M_impl
._M_finish
- this->_M_impl
._M_start
; }
843 /** Returns the size() of the largest possible %deque. */
846 { return size_type(-1); }
849 * @brief Resizes the %deque to the specified number of elements.
850 * @param new_size Number of elements the %deque should contain.
851 * @param x Data with which new elements should be populated.
853 * This function will %resize the %deque to the specified
854 * number of elements. If the number is smaller than the
855 * %deque's current size the %deque is truncated, otherwise the
856 * %deque is extended and new elements are populated with given
860 resize(size_type __new_size
, const value_type
& __x
)
862 const size_type __len
= size();
863 if (__new_size
< __len
)
864 erase(this->_M_impl
._M_start
+ __new_size
, this->_M_impl
._M_finish
);
866 insert(this->_M_impl
._M_finish
, __new_size
- __len
, __x
);
870 * @brief Resizes the %deque to the specified number of elements.
871 * @param new_size Number of elements the %deque should contain.
873 * This function will resize the %deque to the specified number
874 * of elements. If the number is smaller than the %deque's
875 * current size the %deque is truncated, otherwise the %deque
876 * is extended and new elements are default-constructed.
879 resize(size_type new_size
)
880 { resize(new_size
, value_type()); }
883 * Returns true if the %deque is empty. (Thus begin() would
888 { return this->_M_impl
._M_finish
== this->_M_impl
._M_start
; }
892 * @brief Subscript access to the data contained in the %deque.
893 * @param n The index of the element for which data should be
895 * @return Read/write reference to data.
897 * This operator allows for easy, array-style, data access.
898 * Note that data access with this operator is unchecked and
899 * out_of_range lookups are not defined. (For checked lookups
903 operator[](size_type __n
)
904 { return this->_M_impl
._M_start
[difference_type(__n
)]; }
907 * @brief Subscript access to the data contained in the %deque.
908 * @param n The index of the element for which data should be
910 * @return Read-only (constant) reference to data.
912 * This operator allows for easy, array-style, data access.
913 * Note that data access with this operator is unchecked and
914 * out_of_range lookups are not defined. (For checked lookups
918 operator[](size_type __n
) const
919 { return this->_M_impl
._M_start
[difference_type(__n
)]; }
922 /// @if maint Safety check used only from at(). @endif
924 _M_range_check(size_type __n
) const
926 if (__n
>= this->size())
927 __throw_out_of_range(__N("deque::_M_range_check"));
932 * @brief Provides access to the data contained in the %deque.
933 * @param n The index of the element for which data should be
935 * @return Read/write reference to data.
936 * @throw std::out_of_range If @a n is an invalid index.
938 * This function provides for safer data access. The parameter
939 * is first checked that it is in the range of the deque. The
940 * function throws out_of_range if the check fails.
950 * @brief Provides access to the data contained in the %deque.
951 * @param n The index of the element for which data should be
953 * @return Read-only (constant) reference to data.
954 * @throw std::out_of_range If @a n is an invalid index.
956 * This function provides for safer data access. The parameter is first
957 * checked that it is in the range of the deque. The function throws
958 * out_of_range if the check fails.
961 at(size_type __n
) const
968 * Returns a read/write reference to the data at the first
969 * element of the %deque.
973 { return *this->_M_impl
._M_start
; }
976 * Returns a read-only (constant) reference to the data at the first
977 * element of the %deque.
981 { return *this->_M_impl
._M_start
; }
984 * Returns a read/write reference to the data at the last element of the
990 iterator __tmp
= this->_M_impl
._M_finish
;
996 * Returns a read-only (constant) reference to the data at the last
997 * element of the %deque.
1002 const_iterator __tmp
= this->_M_impl
._M_finish
;
1007 // [23.2.1.2] modifiers
1009 * @brief Add data to the front of the %deque.
1010 * @param x Data to be added.
1012 * This is a typical stack operation. The function creates an
1013 * element at the front of the %deque and assigns the given
1014 * data to it. Due to the nature of a %deque this operation
1015 * can be done in constant time.
1018 push_front(const value_type
& __x
)
1020 if (this->_M_impl
._M_start
._M_cur
!= this->_M_impl
._M_start
._M_first
)
1022 this->_M_impl
.construct(this->_M_impl
._M_start
._M_cur
- 1, __x
);
1023 --this->_M_impl
._M_start
._M_cur
;
1026 _M_push_front_aux(__x
);
1030 * @brief Add data to the end of the %deque.
1031 * @param x Data to be added.
1033 * This is a typical stack operation. The function creates an
1034 * element at the end of the %deque and assigns the given data
1035 * to it. Due to the nature of a %deque this operation can be
1036 * done in constant time.
1039 push_back(const value_type
& __x
)
1041 if (this->_M_impl
._M_finish
._M_cur
1042 != this->_M_impl
._M_finish
._M_last
- 1)
1044 this->_M_impl
.construct(this->_M_impl
._M_finish
._M_cur
, __x
);
1045 ++this->_M_impl
._M_finish
._M_cur
;
1048 _M_push_back_aux(__x
);
1052 * @brief Removes first element.
1054 * This is a typical stack operation. It shrinks the %deque by one.
1056 * Note that no data is returned, and if the first element's data is
1057 * needed, it should be retrieved before pop_front() is called.
1062 if (this->_M_impl
._M_start
._M_cur
1063 != this->_M_impl
._M_start
._M_last
- 1)
1065 this->_M_impl
.destroy(this->_M_impl
._M_start
._M_cur
);
1066 ++this->_M_impl
._M_start
._M_cur
;
1073 * @brief Removes last element.
1075 * This is a typical stack operation. It shrinks the %deque by one.
1077 * Note that no data is returned, and if the last element's data is
1078 * needed, it should be retrieved before pop_back() is called.
1083 if (this->_M_impl
._M_finish
._M_cur
1084 != this->_M_impl
._M_finish
._M_first
)
1086 --this->_M_impl
._M_finish
._M_cur
;
1087 this->_M_impl
.destroy(this->_M_impl
._M_finish
._M_cur
);
1094 * @brief Inserts given value into %deque before specified iterator.
1095 * @param position An iterator into the %deque.
1096 * @param x Data to be inserted.
1097 * @return An iterator that points to the inserted data.
1099 * This function will insert a copy of the given value before the
1100 * specified location.
1103 insert(iterator position
, const value_type
& __x
);
1106 * @brief Inserts a number of copies of given data into the %deque.
1107 * @param position An iterator into the %deque.
1108 * @param n Number of elements to be inserted.
1109 * @param x Data to be inserted.
1111 * This function will insert a specified number of copies of the given
1112 * data before the location specified by @a position.
1115 insert(iterator __position
, size_type __n
, const value_type
& __x
)
1116 { _M_fill_insert(__position
, __n
, __x
); }
1119 * @brief Inserts a range into the %deque.
1120 * @param position An iterator into the %deque.
1121 * @param first An input iterator.
1122 * @param last An input iterator.
1124 * This function will insert copies of the data in the range
1125 * [first,last) into the %deque before the location specified
1126 * by @a pos. This is known as "range insert."
1128 template<typename _InputIterator
>
1130 insert(iterator __position
, _InputIterator __first
,
1131 _InputIterator __last
)
1133 // Check whether it's an integral type. If so, it's not an iterator.
1134 typedef typename _Is_integer
<_InputIterator
>::_Integral _Integral
;
1135 _M_insert_dispatch(__position
, __first
, __last
, _Integral());
1139 * @brief Remove element at given position.
1140 * @param position Iterator pointing to element to be erased.
1141 * @return An iterator pointing to the next element (or end()).
1143 * This function will erase the element at the given position and thus
1144 * shorten the %deque by one.
1146 * The user is cautioned that
1147 * this function only erases the element, and that if the element is
1148 * itself a pointer, the pointed-to memory is not touched in any way.
1149 * Managing the pointer is the user's responsibilty.
1152 erase(iterator __position
);
1155 * @brief Remove a range of elements.
1156 * @param first Iterator pointing to the first element to be erased.
1157 * @param last Iterator pointing to one past the last element to be
1159 * @return An iterator pointing to the element pointed to by @a last
1160 * prior to erasing (or end()).
1162 * This function will erase the elements in the range [first,last) and
1163 * shorten the %deque accordingly.
1165 * The user is cautioned that
1166 * this function only erases the elements, and that if the elements
1167 * themselves are pointers, the pointed-to memory is not touched in any
1168 * way. Managing the pointer is the user's responsibilty.
1171 erase(iterator __first
, iterator __last
);
1174 * @brief Swaps data with another %deque.
1175 * @param x A %deque of the same element and allocator types.
1177 * This exchanges the elements between two deques in constant time.
1178 * (Four pointers, so it should be quite fast.)
1179 * Note that the global std::swap() function is specialized such that
1180 * std::swap(d1,d2) will feed to this function.
1185 std::swap(this->_M_impl
._M_start
, __x
._M_impl
._M_start
);
1186 std::swap(this->_M_impl
._M_finish
, __x
._M_impl
._M_finish
);
1187 std::swap(this->_M_impl
._M_map
, __x
._M_impl
._M_map
);
1188 std::swap(this->_M_impl
._M_map_size
, __x
._M_impl
._M_map_size
);
1192 * Erases all the elements. Note that this function only erases the
1193 * elements, and that if the elements themselves are pointers, the
1194 * pointed-to memory is not touched in any way. Managing the pointer is
1195 * the user's responsibilty.
1200 // Internal constructor functions follow.
1202 // called by the range constructor to implement [23.1.1]/9
1203 template<typename _Integer
>
1205 _M_initialize_dispatch(_Integer __n
, _Integer __x
, __true_type
)
1207 _M_initialize_map(__n
);
1208 _M_fill_initialize(__x
);
1211 // called by the range constructor to implement [23.1.1]/9
1212 template<typename _InputIterator
>
1214 _M_initialize_dispatch(_InputIterator __first
, _InputIterator __last
,
1217 typedef typename iterator_traits
<_InputIterator
>::iterator_category
1219 _M_range_initialize(__first
, __last
, _IterCategory());
1222 // called by the second initialize_dispatch above
1226 * @brief Fills the deque with whatever is in [first,last).
1227 * @param first An input iterator.
1228 * @param last An input iterator.
1231 * If the iterators are actually forward iterators (or better), then the
1232 * memory layout can be done all at once. Else we move forward using
1233 * push_back on each value from the iterator.
1236 template<typename _InputIterator
>
1238 _M_range_initialize(_InputIterator __first
, _InputIterator __last
,
1239 input_iterator_tag
);
1241 // called by the second initialize_dispatch above
1242 template<typename _ForwardIterator
>
1244 _M_range_initialize(_ForwardIterator __first
, _ForwardIterator __last
,
1245 forward_iterator_tag
);
1250 * @brief Fills the %deque with copies of value.
1251 * @param value Initial value.
1253 * @pre _M_start and _M_finish have already been initialized,
1254 * but none of the %deque's elements have yet been constructed.
1256 * This function is called only when the user provides an explicit size
1257 * (with or without an explicit exemplar value).
1261 _M_fill_initialize(const value_type
& __value
);
1263 // Internal assign functions follow. The *_aux functions do the actual
1264 // assignment work for the range versions.
1266 // called by the range assign to implement [23.1.1]/9
1267 template<typename _Integer
>
1269 _M_assign_dispatch(_Integer __n
, _Integer __val
, __true_type
)
1271 _M_fill_assign(static_cast<size_type
>(__n
),
1272 static_cast<value_type
>(__val
));
1275 // called by the range assign to implement [23.1.1]/9
1276 template<typename _InputIterator
>
1278 _M_assign_dispatch(_InputIterator __first
, _InputIterator __last
,
1281 typedef typename iterator_traits
<_InputIterator
>::iterator_category
1283 _M_assign_aux(__first
, __last
, _IterCategory());
1286 // called by the second assign_dispatch above
1287 template<typename _InputIterator
>
1289 _M_assign_aux(_InputIterator __first
, _InputIterator __last
,
1290 input_iterator_tag
);
1292 // called by the second assign_dispatch above
1293 template<typename _ForwardIterator
>
1295 _M_assign_aux(_ForwardIterator __first
, _ForwardIterator __last
,
1296 forward_iterator_tag
)
1298 const size_type __len
= std::distance(__first
, __last
);
1301 _ForwardIterator __mid
= __first
;
1302 std::advance(__mid
, size());
1303 std::copy(__first
, __mid
, begin());
1304 insert(end(), __mid
, __last
);
1307 erase(std::copy(__first
, __last
, begin()), end());
1310 // Called by assign(n,t), and the range assign when it turns out
1311 // to be the same thing.
1313 _M_fill_assign(size_type __n
, const value_type
& __val
)
1317 std::fill(begin(), end(), __val
);
1318 insert(end(), __n
- size(), __val
);
1322 erase(begin() + __n
, end());
1323 std::fill(begin(), end(), __val
);
1330 * @brief Helper functions for push_* and pop_*.
1333 void _M_push_back_aux(const value_type
&);
1334 void _M_push_front_aux(const value_type
&);
1335 void _M_pop_back_aux();
1336 void _M_pop_front_aux();
1339 // Internal insert functions follow. The *_aux functions do the actual
1340 // insertion work when all shortcuts fail.
1342 // called by the range insert to implement [23.1.1]/9
1343 template<typename _Integer
>
1345 _M_insert_dispatch(iterator __pos
,
1346 _Integer __n
, _Integer __x
, __true_type
)
1348 _M_fill_insert(__pos
, static_cast<size_type
>(__n
),
1349 static_cast<value_type
>(__x
));
1352 // called by the range insert to implement [23.1.1]/9
1353 template<typename _InputIterator
>
1355 _M_insert_dispatch(iterator __pos
,
1356 _InputIterator __first
, _InputIterator __last
,
1359 typedef typename iterator_traits
<_InputIterator
>::iterator_category
1361 _M_range_insert_aux(__pos
, __first
, __last
, _IterCategory());
1364 // called by the second insert_dispatch above
1365 template<typename _InputIterator
>
1367 _M_range_insert_aux(iterator __pos
, _InputIterator __first
,
1368 _InputIterator __last
, input_iterator_tag
);
1370 // called by the second insert_dispatch above
1371 template<typename _ForwardIterator
>
1373 _M_range_insert_aux(iterator __pos
, _ForwardIterator __first
,
1374 _ForwardIterator __last
, forward_iterator_tag
);
1376 // Called by insert(p,n,x), and the range insert when it turns out to be
1377 // the same thing. Can use fill functions in optimal situations,
1378 // otherwise passes off to insert_aux(p,n,x).
1380 _M_fill_insert(iterator __pos
, size_type __n
, const value_type
& __x
);
1382 // called by insert(p,x)
1384 _M_insert_aux(iterator __pos
, const value_type
& __x
);
1386 // called by insert(p,n,x) via fill_insert
1388 _M_insert_aux(iterator __pos
, size_type __n
, const value_type
& __x
);
1390 // called by range_insert_aux for forward iterators
1391 template<typename _ForwardIterator
>
1393 _M_insert_aux(iterator __pos
,
1394 _ForwardIterator __first
, _ForwardIterator __last
,
1400 * @brief Memory-handling helpers for the previous internal insert
1405 _M_reserve_elements_at_front(size_type __n
)
1407 const size_type __vacancies
= this->_M_impl
._M_start
._M_cur
1408 - this->_M_impl
._M_start
._M_first
;
1409 if (__n
> __vacancies
)
1410 _M_new_elements_at_front(__n
- __vacancies
);
1411 return this->_M_impl
._M_start
- difference_type(__n
);
1415 _M_reserve_elements_at_back(size_type __n
)
1417 const size_type __vacancies
= (this->_M_impl
._M_finish
._M_last
1418 - this->_M_impl
._M_finish
._M_cur
) - 1;
1419 if (__n
> __vacancies
)
1420 _M_new_elements_at_back(__n
- __vacancies
);
1421 return this->_M_impl
._M_finish
+ difference_type(__n
);
1425 _M_new_elements_at_front(size_type __new_elements
);
1428 _M_new_elements_at_back(size_type __new_elements
);
1435 * @brief Memory-handling helpers for the major %map.
1437 * Makes sure the _M_map has space for new nodes. Does not
1438 * actually add the nodes. Can invalidate _M_map pointers.
1439 * (And consequently, %deque iterators.)
1443 _M_reserve_map_at_back (size_type __nodes_to_add
= 1)
1445 if (__nodes_to_add
+ 1 > this->_M_impl
._M_map_size
1446 - (this->_M_impl
._M_finish
._M_node
- this->_M_impl
._M_map
))
1447 _M_reallocate_map(__nodes_to_add
, false);
1451 _M_reserve_map_at_front (size_type __nodes_to_add
= 1)
1453 if (__nodes_to_add
> size_type(this->_M_impl
._M_start
._M_node
1454 - this->_M_impl
._M_map
))
1455 _M_reallocate_map(__nodes_to_add
, true);
1459 _M_reallocate_map(size_type __nodes_to_add
, bool __add_at_front
);
1465 * @brief Deque equality comparison.
1466 * @param x A %deque.
1467 * @param y A %deque of the same type as @a x.
1468 * @return True iff the size and elements of the deques are equal.
1470 * This is an equivalence relation. It is linear in the size of the
1471 * deques. Deques are considered equivalent if their sizes are equal,
1472 * and if corresponding elements compare equal.
1474 template<typename _Tp
, typename _Alloc
>
1476 operator==(const deque
<_Tp
, _Alloc
>& __x
,
1477 const deque
<_Tp
, _Alloc
>& __y
)
1478 { return __x
.size() == __y
.size()
1479 && std::equal(__x
.begin(), __x
.end(), __y
.begin()); }
1482 * @brief Deque ordering relation.
1483 * @param x A %deque.
1484 * @param y A %deque of the same type as @a x.
1485 * @return True iff @a x is lexicographically less than @a y.
1487 * This is a total ordering relation. It is linear in the size of the
1488 * deques. The elements must be comparable with @c <.
1490 * See std::lexicographical_compare() for how the determination is made.
1492 template<typename _Tp
, typename _Alloc
>
1494 operator<(const deque
<_Tp
, _Alloc
>& __x
,
1495 const deque
<_Tp
, _Alloc
>& __y
)
1496 { return lexicographical_compare(__x
.begin(), __x
.end(),
1497 __y
.begin(), __y
.end()); }
1499 /// Based on operator==
1500 template<typename _Tp
, typename _Alloc
>
1502 operator!=(const deque
<_Tp
, _Alloc
>& __x
,
1503 const deque
<_Tp
, _Alloc
>& __y
)
1504 { return !(__x
== __y
); }
1506 /// Based on operator<
1507 template<typename _Tp
, typename _Alloc
>
1509 operator>(const deque
<_Tp
, _Alloc
>& __x
,
1510 const deque
<_Tp
, _Alloc
>& __y
)
1511 { return __y
< __x
; }
1513 /// Based on operator<
1514 template<typename _Tp
, typename _Alloc
>
1516 operator<=(const deque
<_Tp
, _Alloc
>& __x
,
1517 const deque
<_Tp
, _Alloc
>& __y
)
1518 { return !(__y
< __x
); }
1520 /// Based on operator<
1521 template<typename _Tp
, typename _Alloc
>
1523 operator>=(const deque
<_Tp
, _Alloc
>& __x
,
1524 const deque
<_Tp
, _Alloc
>& __y
)
1525 { return !(__x
< __y
); }
1527 /// See std::deque::swap().
1528 template<typename _Tp
, typename _Alloc
>
1530 swap(deque
<_Tp
,_Alloc
>& __x
, deque
<_Tp
,_Alloc
>& __y
)
1534 #endif /* _DEQUE_H */