1// Set implementation -*- C++ -*-
2
3// Copyright (C) 2001-2014 Free Software Foundation, Inc.
4//
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 3, or (at your option)
9// any later version.
10
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.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23// <http://www.gnu.org/licenses/>.
24
25/*
26 *
27 * Copyright (c) 1994
28 * Hewlett-Packard Company
29 *
30 * Permission to use, copy, modify, distribute and sell this software
31 * and its documentation for any purpose is hereby granted without fee,
32 * provided that the above copyright notice appear in all copies and
33 * that both that copyright notice and this permission notice appear
34 * in supporting documentation. Hewlett-Packard Company makes no
35 * representations about the suitability of this software for any
36 * purpose. It is provided "as is" without express or implied warranty.
37 *
38 *
39 * Copyright (c) 1996,1997
40 * Silicon Graphics Computer Systems, Inc.
41 *
42 * Permission to use, copy, modify, distribute and sell this software
43 * and its documentation for any purpose is hereby granted without fee,
44 * provided that the above copyright notice appear in all copies and
45 * that both that copyright notice and this permission notice appear
46 * in supporting documentation. Silicon Graphics makes no
47 * representations about the suitability of this software for any
48 * purpose. It is provided "as is" without express or implied warranty.
49 */
50
51/** @file bits/stl_set.h
52 * This is an internal header file, included by other library headers.
53 * Do not attempt to use it directly. @headername{set}
54 */
55
56#ifndef _STL_SET_H
57#define _STL_SET_H 1
58
59#include <bits/concept_check.h>
60#if __cplusplus >= 201103L
61#include <initializer_list>
62#endif
63
64namespace std _GLIBCXX_VISIBILITY(default)
65{
66_GLIBCXX_BEGIN_NAMESPACE_CONTAINER
67
68 /**
69 * @brief A standard container made up of unique keys, which can be
70 * retrieved in logarithmic time.
71 *
72 * @ingroup associative_containers
73 *
74 * @tparam _Key Type of key objects.
75 * @tparam _Compare Comparison function object type, defaults to less<_Key>.
76 * @tparam _Alloc Allocator type, defaults to allocator<_Key>.
77 *
78 * Meets the requirements of a <a href="tables.html#65">container</a>, a
79 * <a href="tables.html#66">reversible container</a>, and an
80 * <a href="tables.html#69">associative container</a> (using unique keys).
81 *
82 * Sets support bidirectional iterators.
83 *
84 * The private tree data is declared exactly the same way for set and
85 * multiset; the distinction is made entirely in how the tree functions are
86 * called (*_unique versus *_equal, same as the standard).
87 */
88 template<typename _Key, typename _Compare = std::less<_Key>,
89 typename _Alloc = std::allocator<_Key> >
90 class set
91 {
92 // concept requirements
93 typedef typename _Alloc::value_type _Alloc_value_type;
94 __glibcxx_class_requires(_Key, _SGIAssignableConcept)
95 __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
96 _BinaryFunctionConcept)
97 __glibcxx_class_requires2(_Key, _Alloc_value_type, _SameTypeConcept)
98
99 public:
100 // typedefs:
101 //@{
102 /// Public typedefs.
103 typedef _Key key_type;
104 typedef _Key value_type;
105 typedef _Compare key_compare;
106 typedef _Compare value_compare;
107 typedef _Alloc allocator_type;
108 //@}
109
110 private:
111 typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
112 rebind<_Key>::other _Key_alloc_type;
113
114 typedef _Rb_tree<key_type, value_type, _Identity<value_type>,
115 key_compare, _Key_alloc_type> _Rep_type;
116 _Rep_type _M_t; // Red-black tree representing set.
117
118 typedef __gnu_cxx::__alloc_traits<_Key_alloc_type> _Alloc_traits;
119
120 public:
121 //@{
122 /// Iterator-related typedefs.
123 typedef typename _Alloc_traits::pointer pointer;
124 typedef typename _Alloc_traits::const_pointer const_pointer;
125 typedef typename _Alloc_traits::reference reference;
126 typedef typename _Alloc_traits::const_reference const_reference;
127 // _GLIBCXX_RESOLVE_LIB_DEFECTS
128 // DR 103. set::iterator is required to be modifiable,
129 // but this allows modification of keys.
130 typedef typename _Rep_type::const_iterator iterator;
131 typedef typename _Rep_type::const_iterator const_iterator;
132 typedef typename _Rep_type::const_reverse_iterator reverse_iterator;
133 typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
134 typedef typename _Rep_type::size_type size_type;
135 typedef typename _Rep_type::difference_type difference_type;
136 //@}
137
138 // allocation/deallocation
139 /**
140 * @brief Default constructor creates no elements.
141 */
142 set()
143 : _M_t() { }
144
145 /**
146 * @brief Creates a %set with no elements.
147 * @param __comp Comparator to use.
148 * @param __a An allocator object.
149 */
150 explicit
151 set(const _Compare& __comp,
152 const allocator_type& __a = allocator_type())
153 : _M_t(__comp, _Key_alloc_type(__a)) { }
154
155 /**
156 * @brief Builds a %set from a range.
157 * @param __first An input iterator.
158 * @param __last An input iterator.
159 *
160 * Create a %set consisting of copies of the elements from
161 * [__first,__last). This is linear in N if the range is
162 * already sorted, and NlogN otherwise (where N is
163 * distance(__first,__last)).
164 */
165 template<typename _InputIterator>
166 set(_InputIterator __first, _InputIterator __last)
167 : _M_t()
168 { _M_t._M_insert_unique(__first, __last); }
169
170 /**
171 * @brief Builds a %set from a range.
172 * @param __first An input iterator.
173 * @param __last An input iterator.
174 * @param __comp A comparison functor.
175 * @param __a An allocator object.
176 *
177 * Create a %set consisting of copies of the elements from
178 * [__first,__last). This is linear in N if the range is
179 * already sorted, and NlogN otherwise (where N is
180 * distance(__first,__last)).
181 */
182 template<typename _InputIterator>
183 set(_InputIterator __first, _InputIterator __last,
184 const _Compare& __comp,
185 const allocator_type& __a = allocator_type())
186 : _M_t(__comp, _Key_alloc_type(__a))
187 { _M_t._M_insert_unique(__first, __last); }
188
189 /**
190 * @brief %Set copy constructor.
191 * @param __x A %set of identical element and allocator types.
192 *
193 * The newly-created %set uses a copy of the allocation object used
194 * by @a __x.
195 */
196 set(const set& __x)
197 : _M_t(__x._M_t) { }
198
199#if __cplusplus >= 201103L
200 /**
201 * @brief %Set move constructor
202 * @param __x A %set of identical element and allocator types.
203 *
204 * The newly-created %set contains the exact contents of @a x.
205 * The contents of @a x are a valid, but unspecified %set.
206 */
207 set(set&& __x)
208 noexcept(is_nothrow_copy_constructible<_Compare>::value)
209 : _M_t(std::move(__x._M_t)) { }
210
211 /**
212 * @brief Builds a %set from an initializer_list.
213 * @param __l An initializer_list.
214 * @param __comp A comparison functor.
215 * @param __a An allocator object.
216 *
217 * Create a %set consisting of copies of the elements in the list.
218 * This is linear in N if the list is already sorted, and NlogN
219 * otherwise (where N is @a __l.size()).
220 */
221 set(initializer_list<value_type> __l,
222 const _Compare& __comp = _Compare(),
223 const allocator_type& __a = allocator_type())
224 : _M_t(__comp, _Key_alloc_type(__a))
225 { _M_t._M_insert_unique(__l.begin(), __l.end()); }
226
227 /// Allocator-extended default constructor.
228 explicit
229 set(const allocator_type& __a)
230 : _M_t(_Compare(), _Key_alloc_type(__a)) { }
231
232 /// Allocator-extended copy constructor.
233 set(const set& __x, const allocator_type& __a)
234 : _M_t(__x._M_t, _Key_alloc_type(__a)) { }
235
236 /// Allocator-extended move constructor.
237 set(set&& __x, const allocator_type& __a)
238 noexcept(is_nothrow_copy_constructible<_Compare>::value
239 && _Alloc_traits::_S_always_equal())
240 : _M_t(std::move(__x._M_t), _Key_alloc_type(__a)) { }
241
242 /// Allocator-extended initialier-list constructor.
243 set(initializer_list<value_type> __l, const allocator_type& __a)
244 : _M_t(_Compare(), _Key_alloc_type(__a))
245 { _M_t._M_insert_unique(__l.begin(), __l.end()); }
246
247 /// Allocator-extended range constructor.
248 template<typename _InputIterator>
249 set(_InputIterator __first, _InputIterator __last,
250 const allocator_type& __a)
251 : _M_t(_Compare(), _Key_alloc_type(__a))
252 { _M_t._M_insert_unique(__first, __last); }
253#endif
254
255 /**
256 * @brief %Set assignment operator.
257 * @param __x A %set of identical element and allocator types.
258 *
259 * All the elements of @a __x are copied, but unlike the copy
260 * constructor, the allocator object is not copied.
261 */
262 set&
263 operator=(const set& __x)
264 {
265 _M_t = __x._M_t;
266 return *this;
267 }
268
269#if __cplusplus >= 201103L
270 /**
271 * @brief %Set move assignment operator.
272 * @param __x A %set of identical element and allocator types.
273 *
274 * The contents of @a __x are moved into this %set (without copying
275 * if the allocators compare equal or get moved on assignment).
276 * Afterwards @a __x is in a valid, but unspecified state.
277 */
278 set&
279 operator=(set&& __x) noexcept(_Alloc_traits::_S_nothrow_move())
280 {
281 if (!_M_t._M_move_assign(__x._M_t))
282 {
283 // The rvalue's allocator cannot be moved and is not equal,
284 // so we need to individually move each element.
285 clear();
286 insert(std::__make_move_if_noexcept_iterator(__x._M_t.begin()),
287 std::__make_move_if_noexcept_iterator(__x._M_t.end()));
288 __x.clear();
289 }
290 return *this;
291 }
292
293 /**
294 * @brief %Set list assignment operator.
295 * @param __l An initializer_list.
296 *
297 * This function fills a %set with copies of the elements in the
298 * initializer list @a __l.
299 *
300 * Note that the assignment completely changes the %set and
301 * that the resulting %set's size is the same as the number
302 * of elements assigned. Old data may be lost.
303 */
304 set&
305 operator=(initializer_list<value_type> __l)
306 {
307 this->clear();
308 this->insert(__l.begin(), __l.end());
309 return *this;
310 }
311#endif
312
313 // accessors:
314
315 /// Returns the comparison object with which the %set was constructed.
316 key_compare
317 key_comp() const
318 { return _M_t.key_comp(); }
319 /// Returns the comparison object with which the %set was constructed.
320 value_compare
321 value_comp() const
322 { return _M_t.key_comp(); }
323 /// Returns the allocator object with which the %set was constructed.
324 allocator_type
325 get_allocator() const _GLIBCXX_NOEXCEPT
326 { return allocator_type(_M_t.get_allocator()); }
327
328 /**
329 * Returns a read-only (constant) iterator that points to the first
330 * element in the %set. Iteration is done in ascending order according
331 * to the keys.
332 */
333 iterator
334 begin() const _GLIBCXX_NOEXCEPT
335 { return _M_t.begin(); }
336
337 /**
338 * Returns a read-only (constant) iterator that points one past the last
339 * element in the %set. Iteration is done in ascending order according
340 * to the keys.
341 */
342 iterator
343 end() const _GLIBCXX_NOEXCEPT
344 { return _M_t.end(); }
345
346 /**
347 * Returns a read-only (constant) iterator that points to the last
348 * element in the %set. Iteration is done in descending order according
349 * to the keys.
350 */
351 reverse_iterator
352 rbegin() const _GLIBCXX_NOEXCEPT
353 { return _M_t.rbegin(); }
354
355 /**
356 * Returns a read-only (constant) reverse iterator that points to the
357 * last pair in the %set. Iteration is done in descending order
358 * according to the keys.
359 */
360 reverse_iterator
361 rend() const _GLIBCXX_NOEXCEPT
362 { return _M_t.rend(); }
363
364#if __cplusplus >= 201103L
365 /**
366 * Returns a read-only (constant) iterator that points to the first
367 * element in the %set. Iteration is done in ascending order according
368 * to the keys.
369 */
370 iterator
371 cbegin() const noexcept
372 { return _M_t.begin(); }
373
374 /**
375 * Returns a read-only (constant) iterator that points one past the last
376 * element in the %set. Iteration is done in ascending order according
377 * to the keys.
378 */
379 iterator
380 cend() const noexcept
381 { return _M_t.end(); }
382
383 /**
384 * Returns a read-only (constant) iterator that points to the last
385 * element in the %set. Iteration is done in descending order according
386 * to the keys.
387 */
388 reverse_iterator
389 crbegin() const noexcept
390 { return _M_t.rbegin(); }
391
392 /**
393 * Returns a read-only (constant) reverse iterator that points to the
394 * last pair in the %set. Iteration is done in descending order
395 * according to the keys.
396 */
397 reverse_iterator
398 crend() const noexcept
399 { return _M_t.rend(); }
400#endif
401
402 /// Returns true if the %set is empty.
403 bool
404 empty() const _GLIBCXX_NOEXCEPT
405 { return _M_t.empty(); }
406
407 /// Returns the size of the %set.
408 size_type
409 size() const _GLIBCXX_NOEXCEPT
410 { return _M_t.size(); }
411
412 /// Returns the maximum size of the %set.
413 size_type
414 max_size() const _GLIBCXX_NOEXCEPT
415 { return _M_t.max_size(); }
416
417 /**
418 * @brief Swaps data with another %set.
419 * @param __x A %set of the same element and allocator types.
420 *
421 * This exchanges the elements between two sets in constant
422 * time. (It is only swapping a pointer, an integer, and an
423 * instance of the @c Compare type (which itself is often
424 * stateless and empty), so it should be quite fast.) Note
425 * that the global std::swap() function is specialized such
426 * that std::swap(s1,s2) will feed to this function.
427 */
428 void
429 swap(set& __x)
430#if __cplusplus >= 201103L
431 noexcept(_Alloc_traits::_S_nothrow_swap())
432#endif
433 { _M_t.swap(__x._M_t); }
434
435 // insert/erase
436#if __cplusplus >= 201103L
437 /**
438 * @brief Attempts to build and insert an element into the %set.
439 * @param __args Arguments used to generate an element.
440 * @return A pair, of which the first element is an iterator that points
441 * to the possibly inserted element, and the second is a bool
442 * that is true if the element was actually inserted.
443 *
444 * This function attempts to build and insert an element into the %set.
445 * A %set relies on unique keys and thus an element is only inserted if
446 * it is not already present in the %set.
447 *
448 * Insertion requires logarithmic time.
449 */
450 template<typename... _Args>
451 std::pair<iterator, bool>
452 emplace(_Args&&... __args)
453 { return _M_t._M_emplace_unique(std::forward<_Args>(__args)...); }
454
455 /**
456 * @brief Attempts to insert an element into the %set.
457 * @param __pos An iterator that serves as a hint as to where the
458 * element should be inserted.
459 * @param __args Arguments used to generate the element to be
460 * inserted.
461 * @return An iterator that points to the element with key equivalent to
462 * the one generated from @a __args (may or may not be the
463 * element itself).
464 *
465 * This function is not concerned about whether the insertion took place,
466 * and thus does not return a boolean like the single-argument emplace()
467 * does. Note that the first parameter is only a hint and can
468 * potentially improve the performance of the insertion process. A bad
469 * hint would cause no gains in efficiency.
470 *
471 * For more on @a hinting, see:
472 * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html
473 *
474 * Insertion requires logarithmic time (if the hint is not taken).
475 */
476 template<typename... _Args>
477 iterator
478 emplace_hint(const_iterator __pos, _Args&&... __args)
479 {
480 return _M_t._M_emplace_hint_unique(__pos,
481 std::forward<_Args>(__args)...);
482 }
483#endif
484
485 /**
486 * @brief Attempts to insert an element into the %set.
487 * @param __x Element to be inserted.
488 * @return A pair, of which the first element is an iterator that points
489 * to the possibly inserted element, and the second is a bool
490 * that is true if the element was actually inserted.
491 *
492 * This function attempts to insert an element into the %set. A %set
493 * relies on unique keys and thus an element is only inserted if it is
494 * not already present in the %set.
495 *
496 * Insertion requires logarithmic time.
497 */
498 std::pair<iterator, bool>
499 insert(const value_type& __x)
500 {
501 std::pair<typename _Rep_type::iterator, bool> __p =
502 _M_t._M_insert_unique(__x);
503 return std::pair<iterator, bool>(__p.first, __p.second);
504 }
505
506#if __cplusplus >= 201103L
507 std::pair<iterator, bool>
508 insert(value_type&& __x)
509 {
510 std::pair<typename _Rep_type::iterator, bool> __p =
511 _M_t._M_insert_unique(std::move(__x));
512 return std::pair<iterator, bool>(__p.first, __p.second);
513 }
514#endif
515
516 /**
517 * @brief Attempts to insert an element into the %set.
518 * @param __position An iterator that serves as a hint as to where the
519 * element should be inserted.
520 * @param __x Element to be inserted.
521 * @return An iterator that points to the element with key of
522 * @a __x (may or may not be the element passed in).
523 *
524 * This function is not concerned about whether the insertion took place,
525 * and thus does not return a boolean like the single-argument insert()
526 * does. Note that the first parameter is only a hint and can
527 * potentially improve the performance of the insertion process. A bad
528 * hint would cause no gains in efficiency.
529 *
530 * For more on @a hinting, see:
531 * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html
532 *
533 * Insertion requires logarithmic time (if the hint is not taken).
534 */
535 iterator
536 insert(const_iterator __position, const value_type& __x)
537 { return _M_t._M_insert_unique_(__position, __x); }
538
539#if __cplusplus >= 201103L
540 iterator
541 insert(const_iterator __position, value_type&& __x)
542 { return _M_t._M_insert_unique_(__position, std::move(__x)); }
543#endif
544
545 /**
546 * @brief A template function that attempts to insert a range
547 * of elements.
548 * @param __first Iterator pointing to the start of the range to be
549 * inserted.
550 * @param __last Iterator pointing to the end of the range.
551 *
552 * Complexity similar to that of the range constructor.
553 */
554 template<typename _InputIterator>
555 void
556 insert(_InputIterator __first, _InputIterator __last)
557 { _M_t._M_insert_unique(__first, __last); }
558
559#if __cplusplus >= 201103L
560 /**
561 * @brief Attempts to insert a list of elements into the %set.
562 * @param __l A std::initializer_list<value_type> of elements
563 * to be inserted.
564 *
565 * Complexity similar to that of the range constructor.
566 */
567 void
568 insert(initializer_list<value_type> __l)
569 { this->insert(__l.begin(), __l.end()); }
570#endif
571
572#if __cplusplus >= 201103L
573 // _GLIBCXX_RESOLVE_LIB_DEFECTS
574 // DR 130. Associative erase should return an iterator.
575 /**
576 * @brief Erases an element from a %set.
577 * @param __position An iterator pointing to the element to be erased.
578 * @return An iterator pointing to the element immediately following
579 * @a __position prior to the element being erased. If no such
580 * element exists, end() is returned.
581 *
582 * This function erases an element, pointed to by the given iterator,
583 * from a %set. Note that this function only erases the element, and
584 * that if the element is itself a pointer, the pointed-to memory is not
585 * touched in any way. Managing the pointer is the user's
586 * responsibility.
587 */
588 _GLIBCXX_ABI_TAG_CXX11
589 iterator
590 erase(const_iterator __position)
591 { return _M_t.erase(__position); }
592#else
593 /**
594 * @brief Erases an element from a %set.
595 * @param position An iterator pointing to the element to be erased.
596 *
597 * This function erases an element, pointed to by the given iterator,
598 * from a %set. Note that this function only erases the element, and
599 * that if the element is itself a pointer, the pointed-to memory is not
600 * touched in any way. Managing the pointer is the user's
601 * responsibility.
602 */
603 void
604 erase(iterator __position)
605 { _M_t.erase(__position); }
606#endif
607
608 /**
609 * @brief Erases elements according to the provided key.
610 * @param __x Key of element to be erased.
611 * @return The number of elements erased.
612 *
613 * This function erases all the elements located by the given key from
614 * a %set.
615 * Note that this function only erases the element, and that if
616 * the element is itself a pointer, the pointed-to memory is not touched
617 * in any way. Managing the pointer is the user's responsibility.
618 */
619 size_type
620 erase(const key_type& __x)
621 { return _M_t.erase(__x); }
622
623#if __cplusplus >= 201103L
624 // _GLIBCXX_RESOLVE_LIB_DEFECTS
625 // DR 130. Associative erase should return an iterator.
626 /**
627 * @brief Erases a [__first,__last) range of elements from a %set.
628 * @param __first Iterator pointing to the start of the range to be
629 * erased.
630
631 * @param __last Iterator pointing to the end of the range to
632 * be erased.
633 * @return The iterator @a __last.
634 *
635 * This function erases a sequence of elements from a %set.
636 * Note that this function only erases the element, and that if
637 * the element is itself a pointer, the pointed-to memory is not touched
638 * in any way. Managing the pointer is the user's responsibility.
639 */
640 _GLIBCXX_ABI_TAG_CXX11
641 iterator
642 erase(const_iterator __first, const_iterator __last)
643 { return _M_t.erase(__first, __last); }
644#else
645 /**
646 * @brief Erases a [first,last) range of elements from a %set.
647 * @param __first Iterator pointing to the start of the range to be
648 * erased.
649 * @param __last Iterator pointing to the end of the range to
650 * be erased.
651 *
652 * This function erases a sequence of elements from a %set.
653 * Note that this function only erases the element, and that if
654 * the element is itself a pointer, the pointed-to memory is not touched
655 * in any way. Managing the pointer is the user's responsibility.
656 */
657 void
658 erase(iterator __first, iterator __last)
659 { _M_t.erase(__first, __last); }
660#endif
661
662 /**
663 * Erases all elements in a %set. Note that this function only erases
664 * the elements, and that if the elements themselves are pointers, the
665 * pointed-to memory is not touched in any way. Managing the pointer is
666 * the user's responsibility.
667 */
668 void
669 clear() _GLIBCXX_NOEXCEPT
670 { _M_t.clear(); }
671
672 // set operations:
673
674 /**
675 * @brief Finds the number of elements.
676 * @param __x Element to located.
677 * @return Number of elements with specified key.
678 *
679 * This function only makes sense for multisets; for set the result will
680 * either be 0 (not present) or 1 (present).
681 */
682 size_type
683 count(const key_type& __x) const
684 { return _M_t.find(__x) == _M_t.end() ? 0 : 1; }
685
686 // _GLIBCXX_RESOLVE_LIB_DEFECTS
687 // 214. set::find() missing const overload
688 //@{
689 /**
690 * @brief Tries to locate an element in a %set.
691 * @param __x Element to be located.
692 * @return Iterator pointing to sought-after element, or end() if not
693 * found.
694 *
695 * This function takes a key and tries to locate the element with which
696 * the key matches. If successful the function returns an iterator
697 * pointing to the sought after element. If unsuccessful it returns the
698 * past-the-end ( @c end() ) iterator.
699 */
700 iterator
701 find(const key_type& __x)
702 { return _M_t.find(__x); }
703
704 const_iterator
705 find(const key_type& __x) const
706 { return _M_t.find(__x); }
707 //@}
708
709 //@{
710 /**
711 * @brief Finds the beginning of a subsequence matching given key.
712 * @param __x Key to be located.
713 * @return Iterator pointing to first element equal to or greater
714 * than key, or end().
715 *
716 * This function returns the first element of a subsequence of elements
717 * that matches the given key. If unsuccessful it returns an iterator
718 * pointing to the first element that has a greater value than given key
719 * or end() if no such element exists.
720 */
721 iterator
722 lower_bound(const key_type& __x)
723 { return _M_t.lower_bound(__x); }
724
725 const_iterator
726 lower_bound(const key_type& __x) const
727 { return _M_t.lower_bound(__x); }
728 //@}
729
730 //@{
731 /**
732 * @brief Finds the end of a subsequence matching given key.
733 * @param __x Key to be located.
734 * @return Iterator pointing to the first element
735 * greater than key, or end().
736 */
737 iterator
738 upper_bound(const key_type& __x)
739 { return _M_t.upper_bound(__x); }
740
741 const_iterator
742 upper_bound(const key_type& __x) const
743 { return _M_t.upper_bound(__x); }
744 //@}
745
746 //@{
747 /**
748 * @brief Finds a subsequence matching given key.
749 * @param __x Key to be located.
750 * @return Pair of iterators that possibly points to the subsequence
751 * matching given key.
752 *
753 * This function is equivalent to
754 * @code
755 * std::make_pair(c.lower_bound(val),
756 * c.upper_bound(val))
757 * @endcode
758 * (but is faster than making the calls separately).
759 *
760 * This function probably only makes sense for multisets.
761 */
762 std::pair<iterator, iterator>
763 equal_range(const key_type& __x)
764 { return _M_t.equal_range(__x); }
765
766 std::pair<const_iterator, const_iterator>
767 equal_range(const key_type& __x) const
768 { return _M_t.equal_range(__x); }
769 //@}
770
771 template<typename _K1, typename _C1, typename _A1>
772 friend bool
773 operator==(const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&);
774
775 template<typename _K1, typename _C1, typename _A1>
776 friend bool
777 operator<(const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&);
778 };
779
780
781 /**
782 * @brief Set equality comparison.
783 * @param __x A %set.
784 * @param __y A %set of the same type as @a x.
785 * @return True iff the size and elements of the sets are equal.
786 *
787 * This is an equivalence relation. It is linear in the size of the sets.
788 * Sets are considered equivalent if their sizes are equal, and if
789 * corresponding elements compare equal.
790 */
791 template<typename _Key, typename _Compare, typename _Alloc>
792 inline bool
793 operator==(const set<_Key, _Compare, _Alloc>& __x,
794 const set<_Key, _Compare, _Alloc>& __y)
795 { return __x._M_t == __y._M_t; }
796
797 /**
798 * @brief Set ordering relation.
799 * @param __x A %set.
800 * @param __y A %set of the same type as @a x.
801 * @return True iff @a __x is lexicographically less than @a __y.
802 *
803 * This is a total ordering relation. It is linear in the size of the
804 * sets. The elements must be comparable with @c <.
805 *
806 * See std::lexicographical_compare() for how the determination is made.
807 */
808 template<typename _Key, typename _Compare, typename _Alloc>
809 inline bool
810 operator<(const set<_Key, _Compare, _Alloc>& __x,
811 const set<_Key, _Compare, _Alloc>& __y)
812 { return __x._M_t < __y._M_t; }
813
814 /// Returns !(x == y).
815 template<typename _Key, typename _Compare, typename _Alloc>
816 inline bool
817 operator!=(const set<_Key, _Compare, _Alloc>& __x,
818 const set<_Key, _Compare, _Alloc>& __y)
819 { return !(__x == __y); }
820
821 /// Returns y < x.
822 template<typename _Key, typename _Compare, typename _Alloc>
823 inline bool
824 operator>(const set<_Key, _Compare, _Alloc>& __x,
825 const set<_Key, _Compare, _Alloc>& __y)
826 { return __y < __x; }
827
828 /// Returns !(y < x)
829 template<typename _Key, typename _Compare, typename _Alloc>
830 inline bool
831 operator<=(const set<_Key, _Compare, _Alloc>& __x,
832 const set<_Key, _Compare, _Alloc>& __y)
833 { return !(__y < __x); }
834
835 /// Returns !(x < y)
836 template<typename _Key, typename _Compare, typename _Alloc>
837 inline bool
838 operator>=(const set<_Key, _Compare, _Alloc>& __x,
839 const set<_Key, _Compare, _Alloc>& __y)
840 { return !(__x < __y); }
841
842 /// See std::set::swap().
843 template<typename _Key, typename _Compare, typename _Alloc>
844 inline void
845 swap(set<_Key, _Compare, _Alloc>& __x, set<_Key, _Compare, _Alloc>& __y)
846 { __x.swap(__y); }
847
848_GLIBCXX_END_NAMESPACE_CONTAINER
849} //namespace std
850#endif /* _STL_SET_H */
851