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 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
;
105 static size_t _S_buffer_size()
106 { return __deque_buf_size(sizeof(_Tp
)); }
108 typedef random_access_iterator_tag iterator_category
;
109 typedef _Tp value_type
;
110 typedef _Ptr pointer
;
111 typedef _Ref reference
;
112 typedef size_t size_type
;
113 typedef ptrdiff_t difference_type
;
114 typedef _Tp
** _Map_pointer
;
115 typedef _Deque_iterator _Self
;
120 _Map_pointer _M_node
;
122 _Deque_iterator(_Tp
* __x
, _Map_pointer __y
)
123 : _M_cur(__x
), _M_first(*__y
),
124 _M_last(*__y
+ _S_buffer_size()), _M_node(__y
) {}
126 _Deque_iterator() : _M_cur(0), _M_first(0), _M_last(0), _M_node(0) {}
128 _Deque_iterator(const iterator
& __x
)
129 : _M_cur(__x
._M_cur
), _M_first(__x
._M_first
),
130 _M_last(__x
._M_last
), _M_node(__x
._M_node
) {}
144 if (_M_cur
== _M_last
)
146 _M_set_node(_M_node
+ 1);
163 if (_M_cur
== _M_first
)
165 _M_set_node(_M_node
- 1);
181 operator+=(difference_type __n
)
183 const difference_type __offset
= __n
+ (_M_cur
- _M_first
);
184 if (__offset
>= 0 && __offset
< difference_type(_S_buffer_size()))
188 const difference_type __node_offset
=
189 __offset
> 0 ? __offset
/ difference_type(_S_buffer_size())
190 : -difference_type((-__offset
- 1)
191 / _S_buffer_size()) - 1;
192 _M_set_node(_M_node
+ __node_offset
);
193 _M_cur
= _M_first
+ (__offset
- __node_offset
194 * difference_type(_S_buffer_size()));
200 operator+(difference_type __n
) const
207 operator-=(difference_type __n
)
208 { return *this += -__n
; }
211 operator-(difference_type __n
) const
218 operator[](difference_type __n
) const
219 { return *(*this + __n
); }
222 * Prepares to traverse new_node. Sets everything except _M_cur, which
223 * should therefore be set by the caller immediately afterwards, based on
224 * _M_first and _M_last.
228 _M_set_node(_Map_pointer __new_node
)
230 _M_node
= __new_node
;
231 _M_first
= *__new_node
;
232 _M_last
= _M_first
+ difference_type(_S_buffer_size());
236 // Note: we also provide overloads whose operands are of the same type in
237 // order to avoid ambiguous overload resolution when std::rel_ops operators
238 // are in scope (for additional details, see libstdc++/3628)
239 template<typename _Tp
, typename _Ref
, typename _Ptr
>
241 operator==(const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __x
,
242 const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __y
)
243 { return __x
._M_cur
== __y
._M_cur
; }
245 template<typename _Tp
, typename _RefL
, typename _PtrL
,
246 typename _RefR
, typename _PtrR
>
248 operator==(const _Deque_iterator
<_Tp
, _RefL
, _PtrL
>& __x
,
249 const _Deque_iterator
<_Tp
, _RefR
, _PtrR
>& __y
)
250 { return __x
._M_cur
== __y
._M_cur
; }
252 template<typename _Tp
, typename _Ref
, typename _Ptr
>
254 operator!=(const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __x
,
255 const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __y
)
256 { return !(__x
== __y
); }
258 template<typename _Tp
, typename _RefL
, typename _PtrL
,
259 typename _RefR
, typename _PtrR
>
261 operator!=(const _Deque_iterator
<_Tp
, _RefL
, _PtrL
>& __x
,
262 const _Deque_iterator
<_Tp
, _RefR
, _PtrR
>& __y
)
263 { return !(__x
== __y
); }
265 template<typename _Tp
, typename _Ref
, typename _Ptr
>
267 operator<(const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __x
,
268 const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __y
)
269 { return (__x
._M_node
== __y
._M_node
) ? (__x
._M_cur
< __y
._M_cur
)
270 : (__x
._M_node
< __y
._M_node
); }
272 template<typename _Tp
, typename _RefL
, typename _PtrL
,
273 typename _RefR
, typename _PtrR
>
275 operator<(const _Deque_iterator
<_Tp
, _RefL
, _PtrL
>& __x
,
276 const _Deque_iterator
<_Tp
, _RefR
, _PtrR
>& __y
)
277 { return (__x
._M_node
== __y
._M_node
) ? (__x
._M_cur
< __y
._M_cur
)
278 : (__x
._M_node
< __y
._M_node
); }
280 template<typename _Tp
, typename _Ref
, typename _Ptr
>
282 operator>(const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __x
,
283 const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __y
)
284 { return __y
< __x
; }
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
)
291 { return __y
< __x
; }
293 template<typename _Tp
, typename _Ref
, typename _Ptr
>
295 operator<=(const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __x
,
296 const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __y
)
297 { return !(__y
< __x
); }
299 template<typename _Tp
, typename _RefL
, typename _PtrL
,
300 typename _RefR
, typename _PtrR
>
302 operator<=(const _Deque_iterator
<_Tp
, _RefL
, _PtrL
>& __x
,
303 const _Deque_iterator
<_Tp
, _RefR
, _PtrR
>& __y
)
304 { return !(__y
< __x
); }
306 template<typename _Tp
, typename _Ref
, typename _Ptr
>
308 operator>=(const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __x
,
309 const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __y
)
310 { return !(__x
< __y
); }
312 template<typename _Tp
, typename _RefL
, typename _PtrL
,
313 typename _RefR
, typename _PtrR
>
315 operator>=(const _Deque_iterator
<_Tp
, _RefL
, _PtrL
>& __x
,
316 const _Deque_iterator
<_Tp
, _RefR
, _PtrR
>& __y
)
317 { return !(__x
< __y
); }
319 // _GLIBCXX_RESOLVE_LIB_DEFECTS
320 // According to the resolution of DR179 not only the various comparison
321 // operators but also operator- must accept mixed iterator/const_iterator
323 template<typename _Tp
, typename _RefL
, typename _PtrL
,
324 typename _RefR
, typename _PtrR
>
325 inline typename _Deque_iterator
<_Tp
, _RefL
, _PtrL
>::difference_type
326 operator-(const _Deque_iterator
<_Tp
, _RefL
, _PtrL
>& __x
,
327 const _Deque_iterator
<_Tp
, _RefR
, _PtrR
>& __y
)
329 return typename _Deque_iterator
<_Tp
, _RefL
, _PtrL
>::difference_type
330 (_Deque_iterator
<_Tp
, _RefL
, _PtrL
>::_S_buffer_size())
331 * (__x
._M_node
- __y
._M_node
- 1) + (__x
._M_cur
- __x
._M_first
)
332 + (__y
._M_last
- __y
._M_cur
);
335 template<typename _Tp
, typename _Ref
, typename _Ptr
>
336 inline _Deque_iterator
<_Tp
, _Ref
, _Ptr
>
337 operator+(ptrdiff_t __n
, const _Deque_iterator
<_Tp
, _Ref
, _Ptr
>& __x
)
338 { return __x
+ __n
; }
342 * Deque base class. This class provides the unified face for %deque's
343 * allocation. This class's constructor and destructor allocate and
344 * deallocate (but do not initialize) storage. This makes %exception
347 * Nothing in this class ever constructs or destroys an actual Tp element.
348 * (Deque handles that itself.) Only/All memory management is performed
352 template<typename _Tp
, typename _Alloc
>
356 typedef _Alloc allocator_type
;
359 get_allocator() const
360 { return *static_cast<const _Alloc
*>(&this->_M_impl
); }
362 typedef _Deque_iterator
<_Tp
, _Tp
&, _Tp
*> iterator
;
363 typedef _Deque_iterator
<_Tp
, const _Tp
&, const _Tp
*> const_iterator
;
365 _Deque_base(const allocator_type
& __a
, size_t __num_elements
)
367 { _M_initialize_map(__num_elements
); }
369 _Deque_base(const allocator_type
& __a
)
376 //This struct encapsulates the implementation of the std::deque
377 //standard container and at the same time makes use of the EBO
378 //for empty allocators.
387 _Deque_impl(const _Alloc
& __a
)
388 : _Alloc(__a
), _M_map(0), _M_map_size(0), _M_start(), _M_finish()
392 typedef typename
_Alloc::template rebind
<_Tp
*>::other _Map_alloc_type
;
393 _Map_alloc_type
_M_get_map_allocator() const
394 { return _Map_alloc_type(this->get_allocator()); }
398 { return _M_impl
._Alloc::allocate(__deque_buf_size(sizeof(_Tp
))); }
401 _M_deallocate_node(_Tp
* __p
)
402 { _M_impl
._Alloc::deallocate(__p
, __deque_buf_size(sizeof(_Tp
))); }
405 _M_allocate_map(size_t __n
)
406 { return _M_get_map_allocator().allocate(__n
); }
409 _M_deallocate_map(_Tp
** __p
, size_t __n
)
410 { _M_get_map_allocator().deallocate(__p
, __n
); }
413 void _M_initialize_map(size_t);
414 void _M_create_nodes(_Tp
** __nstart
, _Tp
** __nfinish
);
415 void _M_destroy_nodes(_Tp
** __nstart
, _Tp
** __nfinish
);
416 enum { _S_initial_map_size
= 8 };
421 template<typename _Tp
, typename _Alloc
>
422 _Deque_base
<_Tp
, _Alloc
>::
425 if (this->_M_impl
._M_map
)
427 _M_destroy_nodes(this->_M_impl
._M_start
._M_node
,
428 this->_M_impl
._M_finish
._M_node
+ 1);
429 _M_deallocate_map(this->_M_impl
._M_map
, this->_M_impl
._M_map_size
);
435 * @brief Layout storage.
436 * @param num_elements The count of T's for which to allocate space
440 * The initial underlying memory layout is a bit complicated...
443 template<typename _Tp
, typename _Alloc
>
445 _Deque_base
<_Tp
, _Alloc
>::
446 _M_initialize_map(size_t __num_elements
)
448 const size_t __num_nodes
= (__num_elements
/ __deque_buf_size(sizeof(_Tp
))
451 this->_M_impl
._M_map_size
= std::max((size_t) _S_initial_map_size
,
452 size_t(__num_nodes
+ 2));
453 this->_M_impl
._M_map
= _M_allocate_map(this->_M_impl
._M_map_size
);
455 // For "small" maps (needing less than _M_map_size nodes), allocation
456 // starts in the middle elements and grows outwards. So nstart may be
457 // the beginning of _M_map, but for small maps it may be as far in as
460 _Tp
** __nstart
= (this->_M_impl
._M_map
461 + (this->_M_impl
._M_map_size
- __num_nodes
) / 2);
462 _Tp
** __nfinish
= __nstart
+ __num_nodes
;
465 { _M_create_nodes(__nstart
, __nfinish
); }
468 _M_deallocate_map(this->_M_impl
._M_map
, this->_M_impl
._M_map_size
);
469 this->_M_impl
._M_map
= 0;
470 this->_M_impl
._M_map_size
= 0;
471 __throw_exception_again
;
474 this->_M_impl
._M_start
._M_set_node(__nstart
);
475 this->_M_impl
._M_finish
._M_set_node(__nfinish
- 1);
476 this->_M_impl
._M_start
._M_cur
= _M_impl
._M_start
._M_first
;
477 this->_M_impl
._M_finish
._M_cur
= (this->_M_impl
._M_finish
._M_first
479 % __deque_buf_size(sizeof(_Tp
)));
482 template<typename _Tp
, typename _Alloc
>
484 _Deque_base
<_Tp
, _Alloc
>::
485 _M_create_nodes(_Tp
** __nstart
, _Tp
** __nfinish
)
490 for (__cur
= __nstart
; __cur
< __nfinish
; ++__cur
)
491 *__cur
= this->_M_allocate_node();
495 _M_destroy_nodes(__nstart
, __cur
);
496 __throw_exception_again
;
500 template<typename _Tp
, typename _Alloc
>
502 _Deque_base
<_Tp
, _Alloc
>::
503 _M_destroy_nodes(_Tp
** __nstart
, _Tp
** __nfinish
)
505 for (_Tp
** __n
= __nstart
; __n
< __nfinish
; ++__n
)
506 _M_deallocate_node(*__n
);
510 * @brief A standard container using fixed-size memory allocation and
511 * constant-time manipulation of elements at either end.
513 * @ingroup Containers
516 * Meets the requirements of a <a href="tables.html#65">container</a>, a
517 * <a href="tables.html#66">reversible container</a>, and a
518 * <a href="tables.html#67">sequence</a>, including the
519 * <a href="tables.html#68">optional sequence requirements</a>.
521 * In previous HP/SGI versions of deque, there was an extra template
522 * parameter so users could control the node size. This extension turned
523 * out to violate the C++ standard (it can be detected using template
524 * template parameters), and it was removed.
527 * Here's how a deque<Tp> manages memory. Each deque has 4 members:
530 * - size_t _M_map_size
531 * - iterator _M_start, _M_finish
533 * map_size is at least 8. %map is an array of map_size pointers-to-"nodes".
534 * (The name %map has nothing to do with the std::map class, and "nodes"
535 * should not be confused with std::list's usage of "node".)
537 * A "node" has no specific type name as such, but it is referred to as
538 * "node" in this file. It is a simple array-of-Tp. If Tp is very large,
539 * there will be one Tp element per node (i.e., an "array" of one).
540 * For non-huge Tp's, node size is inversely related to Tp size: the
541 * larger the Tp, the fewer Tp's will fit in a node. The goal here is to
542 * keep the total size of a node relatively small and constant over different
543 * Tp's, to improve allocator efficiency.
545 * **** As I write this, the nodes are /not/ allocated using the high-speed
546 * memory pool. There are 20 hours left in the year; perhaps I can fix
549 * Not every pointer in the %map array will point to a node. If the initial
550 * number of elements in the deque is small, the /middle/ %map pointers will
551 * be valid, and the ones at the edges will be unused. This same situation
552 * will arise as the %map grows: available %map pointers, if any, will be on
553 * the ends. As new nodes are created, only a subset of the %map's pointers
554 * need 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 means that
567 * an empty deque must have one node, a deque with <N elements (where N is
568 * the node buffer size) must have one node, a deque with N through (2N-1)
569 * elements must have two nodes, etc.
570 * - For every node other than start.node and finish.node, every element in
571 * the node is an initialized object. If start.node == finish.node, then
572 * [start.cur, finish.cur) are initialized objects, and the elements outside
573 * that range are uninitialized storage. Otherwise, [start.cur, start.last)
574 * and [finish.first, finish.cur) are initialized objects, and [start.first,
575 * start.cur) and [finish.cur, finish.last) are uninitialized storage.
576 * - [%map, %map + map_size) is a valid, non-empty range.
577 * - [start.node, finish.node] is a valid range contained within
578 * [%map, %map + map_size).
579 * - A pointer in the range [%map, %map + map_size) points to an allocated
580 * node if and only if the pointer is in the range
581 * [start.node, finish.node].
583 * Here's the magic: nothing in deque is "aware" of the discontiguous
586 * The memory setup and layout occurs in the parent, _Base, and the iterator
587 * class is entirely responsible for "leaping" from one node to the next.
588 * All the implementation routines for deque itself work only through the
589 * start and finish iterators. This keeps the routines simple and sane,
590 * and we can use other standard algorithms as well.
593 template<typename _Tp
, typename _Alloc
= allocator
<_Tp
> >
594 class deque
: protected _Deque_base
<_Tp
, _Alloc
>
596 // concept requirements
597 __glibcxx_class_requires(_Tp
, _SGIAssignableConcept
)
599 typedef _Deque_base
<_Tp
, _Alloc
> _Base
;
602 typedef _Tp value_type
;
603 typedef typename
_Alloc::pointer pointer
;
604 typedef typename
_Alloc::const_pointer const_pointer
;
605 typedef typename
_Alloc::reference reference
;
606 typedef typename
_Alloc::const_reference const_reference
;
607 typedef typename
_Base::iterator iterator
;
608 typedef typename
_Base::const_iterator const_iterator
;
609 typedef std::reverse_iterator
<const_iterator
> const_reverse_iterator
;
610 typedef std::reverse_iterator
<iterator
> reverse_iterator
;
611 typedef size_t size_type
;
612 typedef ptrdiff_t difference_type
;
613 typedef typename
_Base::allocator_type allocator_type
;
616 typedef pointer
* _Map_pointer
;
618 static size_t _S_buffer_size()
619 { return __deque_buf_size(sizeof(_Tp
)); }
621 // Functions controlling memory layout, and nothing else.
622 using _Base::_M_initialize_map
;
623 using _Base::_M_create_nodes
;
624 using _Base::_M_destroy_nodes
;
625 using _Base::_M_allocate_node
;
626 using _Base::_M_deallocate_node
;
627 using _Base::_M_allocate_map
;
628 using _Base::_M_deallocate_map
;
631 * A total of four data members accumulated down the heirarchy.
632 * May be accessed via _M_impl.*
635 using _Base::_M_impl
;
638 // [23.2.1.1] construct/copy/destroy
639 // (assign() and get_allocator() are also listed in this section)
641 * @brief Default constructor creates no elements.
644 deque(const allocator_type
& __a
= allocator_type())
648 * @brief Create a %deque with copies of an exemplar element.
649 * @param n The number of elements to initially create.
650 * @param value An element to copy.
652 * This constructor fills the %deque with @a n copies of @a value.
654 deque(size_type __n
, const value_type
& __value
,
655 const allocator_type
& __a
= allocator_type())
657 { _M_fill_initialize(__value
); }
660 * @brief Create a %deque with default elements.
661 * @param n The number of elements to initially create.
663 * This constructor fills the %deque with @a n copies of a
664 * default-constructed element.
668 : _Base(allocator_type(), __n
)
669 { _M_fill_initialize(value_type()); }
672 * @brief %Deque copy constructor.
673 * @param x A %deque of identical element and allocator types.
675 * The newly-created %deque uses a copy of the allocation object used
678 deque(const deque
& __x
)
679 : _Base(__x
.get_allocator(), __x
.size())
680 { std::uninitialized_copy(__x
.begin(), __x
.end(),
681 this->_M_impl
._M_start
); }
684 * @brief Builds a %deque from a range.
685 * @param first An input iterator.
686 * @param last An input iterator.
688 * Create a %deque consisting of copies of the elements from [first,
691 * If the iterators are forward, bidirectional, or random-access, then
692 * this will call the elements' copy constructor N times (where N is
693 * distance(first,last)) and do no memory reallocation. But if only
694 * input iterators are used, then this will do at most 2N calls to the
695 * copy constructor, and logN memory reallocations.
697 template<typename _InputIterator
>
698 deque(_InputIterator __first
, _InputIterator __last
,
699 const allocator_type
& __a
= allocator_type())
702 // Check whether it's an integral type. If so, it's not an iterator.
703 typedef typename _Is_integer
<_InputIterator
>::_Integral _Integral
;
704 _M_initialize_dispatch(__first
, __last
, _Integral());
708 * The dtor only erases the elements, and note that if the elements
709 * themselves are pointers, the pointed-to memory is not touched in any
710 * way. Managing the pointer is the user's responsibilty.
713 { std::_Destroy(this->_M_impl
._M_start
, this->_M_impl
._M_finish
); }
716 * @brief %Deque assignment operator.
717 * @param x A %deque of identical element and allocator types.
719 * All the elements of @a x are copied, but unlike the copy constructor,
720 * the allocator object is not copied.
723 operator=(const deque
& __x
);
726 * @brief Assigns a given value to a %deque.
727 * @param n Number of elements to be assigned.
728 * @param val Value to be assigned.
730 * This function fills a %deque with @a n copies of the given value.
731 * Note that the assignment completely changes the %deque and that the
732 * resulting %deque's size is the same as the number of elements assigned.
733 * Old data may be lost.
736 assign(size_type __n
, const value_type
& __val
)
737 { _M_fill_assign(__n
, __val
); }
740 * @brief Assigns a range to a %deque.
741 * @param first An input iterator.
742 * @param last An input iterator.
744 * This function fills a %deque with copies of the elements in the
745 * range [first,last).
747 * Note that the assignment completely changes the %deque and that the
748 * resulting %deque's size is the same as the number of elements
749 * assigned. Old data may be lost.
751 template<typename _InputIterator
>
753 assign(_InputIterator __first
, _InputIterator __last
)
755 typedef typename _Is_integer
<_InputIterator
>::_Integral _Integral
;
756 _M_assign_dispatch(__first
, __last
, _Integral());
759 /// Get a copy of the memory allocation object.
761 get_allocator() const
762 { return _Base::get_allocator(); }
766 * Returns a read/write iterator that points to the first element in the
767 * %deque. Iteration is done in ordinary element order.
771 { return this->_M_impl
._M_start
; }
774 * Returns a read-only (constant) iterator that points to the first
775 * element in the %deque. Iteration is done in ordinary element order.
779 { return this->_M_impl
._M_start
; }
782 * Returns a read/write iterator that points one past the last element in
783 * the %deque. Iteration is done in ordinary element order.
787 { return this->_M_impl
._M_finish
; }
790 * Returns a read-only (constant) iterator that points one past the last
791 * element in the %deque. Iteration is done in ordinary element order.
795 { return this->_M_impl
._M_finish
; }
798 * Returns a read/write reverse iterator that points to the last element
799 * in the %deque. Iteration is done in reverse element order.
803 { return reverse_iterator(this->_M_impl
._M_finish
); }
806 * Returns a read-only (constant) reverse iterator that points to the
807 * last element in the %deque. Iteration is done in reverse element
810 const_reverse_iterator
812 { return const_reverse_iterator(this->_M_impl
._M_finish
); }
815 * Returns a read/write reverse iterator that points to one before the
816 * first element in the %deque. Iteration is done in reverse element
820 rend() { return reverse_iterator(this->_M_impl
._M_start
); }
823 * Returns a read-only (constant) reverse iterator that points to one
824 * before the first element in the %deque. Iteration is done in reverse
827 const_reverse_iterator
829 { return const_reverse_iterator(this->_M_impl
._M_start
); }
831 // [23.2.1.2] capacity
832 /** Returns the number of elements in the %deque. */
835 { return this->_M_impl
._M_finish
- this->_M_impl
._M_start
; }
837 /** Returns the size() of the largest possible %deque. */
840 { return size_type(-1); }
843 * @brief Resizes the %deque to the specified number of elements.
844 * @param new_size Number of elements the %deque should contain.
845 * @param x Data with which new elements should be populated.
847 * This function will %resize the %deque to the specified number of
848 * elements. If the number is smaller than the %deque's current size the
849 * %deque is truncated, otherwise the %deque is extended and new elements
850 * are populated with given data.
853 resize(size_type __new_size
, const value_type
& __x
)
855 const size_type __len
= size();
856 if (__new_size
< __len
)
857 erase(this->_M_impl
._M_start
+ __new_size
, this->_M_impl
._M_finish
);
859 insert(this->_M_impl
._M_finish
, __new_size
- __len
, __x
);
863 * @brief Resizes the %deque to the specified number of elements.
864 * @param new_size Number of elements the %deque should contain.
866 * This function will resize the %deque to the specified number of
867 * elements. If the number is smaller than the %deque's current size the
868 * %deque is truncated, otherwise the %deque is extended and new elements
869 * are default-constructed.
872 resize(size_type new_size
)
873 { resize(new_size
, value_type()); }
876 * Returns true if the %deque is empty. (Thus begin() would equal end().)
880 { return this->_M_impl
._M_finish
== this->_M_impl
._M_start
; }
884 * @brief Subscript access to the data contained in the %deque.
885 * @param n The index of the element for which data should be accessed.
886 * @return Read/write reference to data.
888 * This operator allows for easy, array-style, data access.
889 * Note that data access with this operator is unchecked and out_of_range
890 * lookups are not defined. (For checked lookups see at().)
893 operator[](size_type __n
)
894 { return this->_M_impl
._M_start
[difference_type(__n
)]; }
897 * @brief Subscript access to the data contained in the %deque.
898 * @param n The index of the element for which data should be accessed.
899 * @return Read-only (constant) reference to data.
901 * This operator allows for easy, array-style, data access.
902 * Note that data access with this operator is unchecked and out_of_range
903 * lookups are not defined. (For checked lookups see at().)
906 operator[](size_type __n
) const
907 { return this->_M_impl
._M_start
[difference_type(__n
)]; }
910 /// @if maint Safety check used only from at(). @endif
912 _M_range_check(size_type __n
) const
914 if (__n
>= this->size())
915 __throw_out_of_range(__N("deque::_M_range_check"));
920 * @brief Provides access to the data contained in the %deque.
921 * @param n The index of the element for which data should be accessed.
922 * @return Read/write reference to data.
923 * @throw std::out_of_range If @a n is an invalid index.
925 * This function provides for safer data access. The parameter is first
926 * checked that it is in the range of the deque. The function throws
927 * out_of_range if the check fails.
937 * @brief Provides access to the data contained in the %deque.
938 * @param n The index of the element for which data should be accessed.
939 * @return Read-only (constant) reference to data.
940 * @throw std::out_of_range If @a n is an invalid index.
942 * This function provides for safer data access. The parameter is first
943 * checked that it is in the range of the deque. The function throws
944 * out_of_range if the check fails.
947 at(size_type __n
) const
954 * Returns a read/write reference to the data at the first element of the
959 { return *this->_M_impl
._M_start
; }
962 * Returns a read-only (constant) reference to the data at the first
963 * element of the %deque.
967 { return *this->_M_impl
._M_start
; }
970 * Returns a read/write reference to the data at the last element of the
976 iterator __tmp
= this->_M_impl
._M_finish
;
982 * Returns a read-only (constant) reference to the data at the last
983 * element of the %deque.
988 const_iterator __tmp
= this->_M_impl
._M_finish
;
993 // [23.2.1.2] modifiers
995 * @brief Add data to the front of the %deque.
996 * @param x Data to be added.
998 * This is a typical stack operation. The function creates an element at
999 * the front of the %deque and assigns the given data to it. Due to the
1000 * nature of a %deque this operation can be done in constant time.
1003 push_front(const value_type
& __x
)
1005 if (this->_M_impl
._M_start
._M_cur
!= this->_M_impl
._M_start
._M_first
)
1007 std::_Construct(this->_M_impl
._M_start
._M_cur
- 1, __x
);
1008 --this->_M_impl
._M_start
._M_cur
;
1011 _M_push_front_aux(__x
);
1015 * @brief Add data to the end of the %deque.
1016 * @param x Data to be added.
1018 * This is a typical stack operation. The function creates an element at
1019 * the end of the %deque and assigns the given data to it. Due to the
1020 * nature of a %deque this operation can be done in constant time.
1023 push_back(const value_type
& __x
)
1025 if (this->_M_impl
._M_finish
._M_cur
1026 != this->_M_impl
._M_finish
._M_last
- 1)
1028 std::_Construct(this->_M_impl
._M_finish
._M_cur
, __x
);
1029 ++this->_M_impl
._M_finish
._M_cur
;
1032 _M_push_back_aux(__x
);
1036 * @brief Removes first element.
1038 * This is a typical stack operation. It shrinks the %deque by one.
1040 * Note that no data is returned, and if the first element's data is
1041 * needed, it should be retrieved before pop_front() is called.
1046 if (this->_M_impl
._M_start
._M_cur
1047 != this->_M_impl
._M_start
._M_last
- 1)
1049 std::_Destroy(this->_M_impl
._M_start
._M_cur
);
1050 ++this->_M_impl
._M_start
._M_cur
;
1057 * @brief Removes last element.
1059 * This is a typical stack operation. It shrinks the %deque by one.
1061 * Note that no data is returned, and if the last element's data is
1062 * needed, it should be retrieved before pop_back() is called.
1067 if (this->_M_impl
._M_finish
._M_cur
1068 != this->_M_impl
._M_finish
._M_first
)
1070 --this->_M_impl
._M_finish
._M_cur
;
1071 std::_Destroy(this->_M_impl
._M_finish
._M_cur
);
1078 * @brief Inserts given value into %deque before specified iterator.
1079 * @param position An iterator into the %deque.
1080 * @param x Data to be inserted.
1081 * @return An iterator that points to the inserted data.
1083 * This function will insert a copy of the given value before the
1084 * specified location.
1087 insert(iterator position
, const value_type
& __x
);
1090 * @brief Inserts a number of copies of given data into the %deque.
1091 * @param position An iterator into the %deque.
1092 * @param n Number of elements to be inserted.
1093 * @param x Data to be inserted.
1095 * This function will insert a specified number of copies of the given
1096 * data before the location specified by @a position.
1099 insert(iterator __position
, size_type __n
, const value_type
& __x
)
1100 { _M_fill_insert(__position
, __n
, __x
); }
1103 * @brief Inserts a range into the %deque.
1104 * @param position An iterator into the %deque.
1105 * @param first An input iterator.
1106 * @param last An input iterator.
1108 * This function will insert copies of the data in the range [first,last)
1109 * into the %deque before the location specified by @a pos. This is
1110 * known as "range insert."
1112 template<typename _InputIterator
>
1114 insert(iterator __position
, _InputIterator __first
,
1115 _InputIterator __last
)
1117 // Check whether it's an integral type. If so, it's not an iterator.
1118 typedef typename _Is_integer
<_InputIterator
>::_Integral _Integral
;
1119 _M_insert_dispatch(__position
, __first
, __last
, _Integral());
1123 * @brief Remove element at given position.
1124 * @param position Iterator pointing to element to be erased.
1125 * @return An iterator pointing to the next element (or end()).
1127 * This function will erase the element at the given position and thus
1128 * shorten the %deque by one.
1130 * The user is cautioned that
1131 * this function only erases the element, and that if the element is
1132 * itself a pointer, the pointed-to memory is not touched in any way.
1133 * Managing the pointer is the user's responsibilty.
1136 erase(iterator __position
);
1139 * @brief Remove a range of elements.
1140 * @param first Iterator pointing to the first element to be erased.
1141 * @param last Iterator pointing to one past the last element to be
1143 * @return An iterator pointing to the element pointed to by @a last
1144 * prior to erasing (or end()).
1146 * This function will erase the elements in the range [first,last) and
1147 * shorten the %deque accordingly.
1149 * The user is cautioned that
1150 * this function only erases the elements, and that if the elements
1151 * themselves are pointers, the pointed-to memory is not touched in any
1152 * way. Managing the pointer is the user's responsibilty.
1155 erase(iterator __first
, iterator __last
);
1158 * @brief Swaps data with another %deque.
1159 * @param x A %deque of the same element and allocator types.
1161 * This exchanges the elements between two deques in constant time.
1162 * (Four pointers, so it should be quite fast.)
1163 * Note that the global std::swap() function is specialized such that
1164 * std::swap(d1,d2) will feed to this function.
1169 std::swap(this->_M_impl
._M_start
, __x
._M_impl
._M_start
);
1170 std::swap(this->_M_impl
._M_finish
, __x
._M_impl
._M_finish
);
1171 std::swap(this->_M_impl
._M_map
, __x
._M_impl
._M_map
);
1172 std::swap(this->_M_impl
._M_map_size
, __x
._M_impl
._M_map_size
);
1176 * Erases all the elements. Note that this function only erases the
1177 * elements, and that if the elements themselves are pointers, the
1178 * pointed-to memory is not touched in any way. Managing the pointer is
1179 * the user's responsibilty.
1184 // Internal constructor functions follow.
1186 // called by the range constructor to implement [23.1.1]/9
1187 template<typename _Integer
>
1189 _M_initialize_dispatch(_Integer __n
, _Integer __x
, __true_type
)
1191 _M_initialize_map(__n
);
1192 _M_fill_initialize(__x
);
1195 // called by the range constructor to implement [23.1.1]/9
1196 template<typename _InputIterator
>
1198 _M_initialize_dispatch(_InputIterator __first
, _InputIterator __last
,
1201 typedef typename iterator_traits
<_InputIterator
>::iterator_category
1203 _M_range_initialize(__first
, __last
, _IterCategory());
1206 // called by the second initialize_dispatch above
1210 * @brief Fills the deque with whatever is in [first,last).
1211 * @param first An input iterator.
1212 * @param last An input iterator.
1215 * If the iterators are actually forward iterators (or better), then the
1216 * memory layout can be done all at once. Else we move forward using
1217 * push_back on each value from the iterator.
1220 template<typename _InputIterator
>
1222 _M_range_initialize(_InputIterator __first
, _InputIterator __last
,
1223 input_iterator_tag
);
1225 // called by the second initialize_dispatch above
1226 template<typename _ForwardIterator
>
1228 _M_range_initialize(_ForwardIterator __first
, _ForwardIterator __last
,
1229 forward_iterator_tag
);
1234 * @brief Fills the %deque with copies of value.
1235 * @param value Initial value.
1237 * @pre _M_start and _M_finish have already been initialized, but none of
1238 * the %deque's elements have yet been constructed.
1240 * This function is called only when the user provides an explicit size
1241 * (with or without an explicit exemplar value).
1245 _M_fill_initialize(const value_type
& __value
);
1247 // Internal assign functions follow. The *_aux functions do the actual
1248 // assignment work for the range versions.
1250 // called by the range assign to implement [23.1.1]/9
1251 template<typename _Integer
>
1253 _M_assign_dispatch(_Integer __n
, _Integer __val
, __true_type
)
1255 _M_fill_assign(static_cast<size_type
>(__n
),
1256 static_cast<value_type
>(__val
));
1259 // called by the range assign to implement [23.1.1]/9
1260 template<typename _InputIterator
>
1262 _M_assign_dispatch(_InputIterator __first
, _InputIterator __last
,
1265 typedef typename iterator_traits
<_InputIterator
>::iterator_category
1267 _M_assign_aux(__first
, __last
, _IterCategory());
1270 // called by the second assign_dispatch above
1271 template<typename _InputIterator
>
1273 _M_assign_aux(_InputIterator __first
, _InputIterator __last
,
1274 input_iterator_tag
);
1276 // called by the second assign_dispatch above
1277 template<typename _ForwardIterator
>
1279 _M_assign_aux(_ForwardIterator __first
, _ForwardIterator __last
,
1280 forward_iterator_tag
)
1282 const size_type __len
= std::distance(__first
, __last
);
1285 _ForwardIterator __mid
= __first
;
1286 std::advance(__mid
, size());
1287 std::copy(__first
, __mid
, begin());
1288 insert(end(), __mid
, __last
);
1291 erase(std::copy(__first
, __last
, begin()), end());
1294 // Called by assign(n,t), and the range assign when it turns out to be the
1297 _M_fill_assign(size_type __n
, const value_type
& __val
)
1301 std::fill(begin(), end(), __val
);
1302 insert(end(), __n
- size(), __val
);
1306 erase(begin() + __n
, end());
1307 std::fill(begin(), end(), __val
);
1314 * @brief Helper functions for push_* and pop_*.
1317 void _M_push_back_aux(const value_type
&);
1318 void _M_push_front_aux(const value_type
&);
1319 void _M_pop_back_aux();
1320 void _M_pop_front_aux();
1323 // Internal insert functions follow. The *_aux functions do the actual
1324 // insertion work when all shortcuts fail.
1326 // called by the range insert to implement [23.1.1]/9
1327 template<typename _Integer
>
1329 _M_insert_dispatch(iterator __pos
,
1330 _Integer __n
, _Integer __x
, __true_type
)
1332 _M_fill_insert(__pos
, static_cast<size_type
>(__n
),
1333 static_cast<value_type
>(__x
));
1336 // called by the range insert to implement [23.1.1]/9
1337 template<typename _InputIterator
>
1339 _M_insert_dispatch(iterator __pos
,
1340 _InputIterator __first
, _InputIterator __last
,
1343 typedef typename iterator_traits
<_InputIterator
>::iterator_category
1345 _M_range_insert_aux(__pos
, __first
, __last
, _IterCategory());
1348 // called by the second insert_dispatch above
1349 template<typename _InputIterator
>
1351 _M_range_insert_aux(iterator __pos
, _InputIterator __first
,
1352 _InputIterator __last
, input_iterator_tag
);
1354 // called by the second insert_dispatch above
1355 template<typename _ForwardIterator
>
1357 _M_range_insert_aux(iterator __pos
, _ForwardIterator __first
,
1358 _ForwardIterator __last
, forward_iterator_tag
);
1360 // Called by insert(p,n,x), and the range insert when it turns out to be
1361 // the same thing. Can use fill functions in optimal situations,
1362 // otherwise passes off to insert_aux(p,n,x).
1364 _M_fill_insert(iterator __pos
, size_type __n
, const value_type
& __x
);
1366 // called by insert(p,x)
1368 _M_insert_aux(iterator __pos
, const value_type
& __x
);
1370 // called by insert(p,n,x) via fill_insert
1372 _M_insert_aux(iterator __pos
, size_type __n
, const value_type
& __x
);
1374 // called by range_insert_aux for forward iterators
1375 template<typename _ForwardIterator
>
1377 _M_insert_aux(iterator __pos
,
1378 _ForwardIterator __first
, _ForwardIterator __last
,
1384 * @brief Memory-handling helpers for the previous internal insert
1389 _M_reserve_elements_at_front(size_type __n
)
1391 const size_type __vacancies
= this->_M_impl
._M_start
._M_cur
1392 - this->_M_impl
._M_start
._M_first
;
1393 if (__n
> __vacancies
)
1394 _M_new_elements_at_front(__n
- __vacancies
);
1395 return this->_M_impl
._M_start
- difference_type(__n
);
1399 _M_reserve_elements_at_back(size_type __n
)
1401 const size_type __vacancies
= (this->_M_impl
._M_finish
._M_last
1402 - this->_M_impl
._M_finish
._M_cur
) - 1;
1403 if (__n
> __vacancies
)
1404 _M_new_elements_at_back(__n
- __vacancies
);
1405 return this->_M_impl
._M_finish
+ difference_type(__n
);
1409 _M_new_elements_at_front(size_type __new_elements
);
1412 _M_new_elements_at_back(size_type __new_elements
);
1419 * @brief Memory-handling helpers for the major %map.
1421 * Makes sure the _M_map has space for new nodes. Does not actually add
1422 * the nodes. Can invalidate _M_map pointers. (And consequently, %deque
1427 _M_reserve_map_at_back (size_type __nodes_to_add
= 1)
1429 if (__nodes_to_add
+ 1 > this->_M_impl
._M_map_size
1430 - (this->_M_impl
._M_finish
._M_node
- this->_M_impl
._M_map
))
1431 _M_reallocate_map(__nodes_to_add
, false);
1435 _M_reserve_map_at_front (size_type __nodes_to_add
= 1)
1437 if (__nodes_to_add
> size_type(this->_M_impl
._M_start
._M_node
1438 - this->_M_impl
._M_map
))
1439 _M_reallocate_map(__nodes_to_add
, true);
1443 _M_reallocate_map(size_type __nodes_to_add
, bool __add_at_front
);
1449 * @brief Deque equality comparison.
1450 * @param x A %deque.
1451 * @param y A %deque of the same type as @a x.
1452 * @return True iff the size and elements of the deques are equal.
1454 * This is an equivalence relation. It is linear in the size of the
1455 * deques. Deques are considered equivalent if their sizes are equal,
1456 * and if corresponding elements compare equal.
1458 template<typename _Tp
, typename _Alloc
>
1460 operator==(const deque
<_Tp
, _Alloc
>& __x
,
1461 const deque
<_Tp
, _Alloc
>& __y
)
1462 { return __x
.size() == __y
.size()
1463 && std::equal(__x
.begin(), __x
.end(), __y
.begin()); }
1466 * @brief Deque ordering relation.
1467 * @param x A %deque.
1468 * @param y A %deque of the same type as @a x.
1469 * @return True iff @a x is lexicographically less than @a y.
1471 * This is a total ordering relation. It is linear in the size of the
1472 * deques. The elements must be comparable with @c <.
1474 * See std::lexicographical_compare() for how the determination is made.
1476 template<typename _Tp
, typename _Alloc
>
1478 operator<(const deque
<_Tp
, _Alloc
>& __x
,
1479 const deque
<_Tp
, _Alloc
>& __y
)
1480 { return lexicographical_compare(__x
.begin(), __x
.end(),
1481 __y
.begin(), __y
.end()); }
1483 /// Based on operator==
1484 template<typename _Tp
, typename _Alloc
>
1486 operator!=(const deque
<_Tp
, _Alloc
>& __x
,
1487 const deque
<_Tp
, _Alloc
>& __y
)
1488 { return !(__x
== __y
); }
1490 /// Based on operator<
1491 template<typename _Tp
, typename _Alloc
>
1493 operator>(const deque
<_Tp
, _Alloc
>& __x
,
1494 const deque
<_Tp
, _Alloc
>& __y
)
1495 { return __y
< __x
; }
1497 /// Based on operator<
1498 template<typename _Tp
, typename _Alloc
>
1500 operator<=(const deque
<_Tp
, _Alloc
>& __x
,
1501 const deque
<_Tp
, _Alloc
>& __y
)
1502 { return !(__y
< __x
); }
1504 /// Based on operator<
1505 template<typename _Tp
, typename _Alloc
>
1507 operator>=(const deque
<_Tp
, _Alloc
>& __x
,
1508 const deque
<_Tp
, _Alloc
>& __y
)
1509 { return !(__x
< __y
); }
1511 /// See std::deque::swap().
1512 template<typename _Tp
, typename _Alloc
>
1514 swap(deque
<_Tp
,_Alloc
>& __x
, deque
<_Tp
,_Alloc
>& __y
)
1518 #endif /* _DEQUE_H */