1 // Bits and pieces used in algorithms -*- C++ -*-
3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 // Free Software Foundation, Inc.
6 // This file is part of the GNU ISO C++ Library. This library is free
7 // software; you can redistribute it and/or modify it under the
8 // terms of the GNU General Public License as published by the
9 // Free Software Foundation; either version 2, or (at your option)
12 // This library is distributed in the hope that it will be useful,
13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 // GNU General Public License for more details.
17 // You should have received a copy of the GNU General Public License along
18 // with this library; see the file COPYING. If not, write to the Free
19 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
22 // As a special exception, you may use this file as part of a free software
23 // library without restriction. Specifically, if other files instantiate
24 // templates or use macros or inline functions from this file, or you compile
25 // this file and link it with other files to produce an executable, this
26 // file does not by itself cause the resulting executable to be covered by
27 // the GNU General Public License. This exception does not however
28 // invalidate any other reasons why the executable file might be covered by
29 // the GNU General Public License.
34 * Hewlett-Packard Company
36 * Permission to use, copy, modify, distribute and sell this software
37 * and its documentation for any purpose is hereby granted without fee,
38 * provided that the above copyright notice appear in all copies and
39 * that both that copyright notice and this permission notice appear
40 * in supporting documentation. Hewlett-Packard Company makes no
41 * representations about the suitability of this software for any
42 * purpose. It is provided "as is" without express or implied warranty.
45 * Copyright (c) 1996-1998
46 * Silicon Graphics Computer Systems, Inc.
48 * Permission to use, copy, modify, distribute and sell this software
49 * and its documentation for any purpose is hereby granted without fee,
50 * provided that the above copyright notice appear in all copies and
51 * that both that copyright notice and this permission notice appear
52 * in supporting documentation. Silicon Graphics makes no
53 * representations about the suitability of this software for any
54 * purpose. It is provided "as is" without express or implied warranty.
57 /** @file stl_algobase.h
58 * This is an internal header file, included by other library headers.
59 * You should not attempt to use it directly.
65 #include <bits/c++config.h>
71 #include <bits/stl_pair.h>
72 #include <bits/cpp_type_traits.h>
73 #include <ext/type_traits.h>
74 #include <bits/stl_iterator_base_types.h>
75 #include <bits/stl_iterator_base_funcs.h>
76 #include <bits/stl_iterator.h>
77 #include <bits/concept_check.h>
78 #include <debug/debug.h>
80 _GLIBCXX_BEGIN_NAMESPACE(std
)
83 * @brief Swaps two values.
84 * @param a A thing of arbitrary type.
85 * @param b Another thing of arbitrary type.
88 * This is the simple classic generic implementation. It will work on
89 * any type which has a copy constructor and an assignment operator.
91 template<typename _Tp
>
93 swap(_Tp
& __a
, _Tp
& __b
)
95 // concept requirements
96 __glibcxx_function_requires(_SGIAssignableConcept
<_Tp
>)
103 // See http://gcc.gnu.org/ml/libstdc++/2004-08/msg00167.html: in a
104 // nutshell, we are partially implementing the resolution of DR 187,
105 // when it's safe, i.e., the value_types are equal.
106 template<bool _BoolType
>
109 template<typename _ForwardIterator1
, typename _ForwardIterator2
>
111 iter_swap(_ForwardIterator1 __a
, _ForwardIterator2 __b
)
113 typedef typename iterator_traits
<_ForwardIterator1
>::value_type
115 _ValueType1 __tmp
= *__a
;
122 struct __iter_swap
<true>
124 template<typename _ForwardIterator1
, typename _ForwardIterator2
>
126 iter_swap(_ForwardIterator1 __a
, _ForwardIterator2 __b
)
133 * @brief Swaps the contents of two iterators.
134 * @param a An iterator.
135 * @param b Another iterator.
138 * This function swaps the values pointed to by two iterators, not the
139 * iterators themselves.
141 template<typename _ForwardIterator1
, typename _ForwardIterator2
>
143 iter_swap(_ForwardIterator1 __a
, _ForwardIterator2 __b
)
145 typedef typename iterator_traits
<_ForwardIterator1
>::value_type
147 typedef typename iterator_traits
<_ForwardIterator2
>::value_type
150 // concept requirements
151 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept
<
153 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept
<
155 __glibcxx_function_requires(_ConvertibleConcept
<_ValueType1
,
157 __glibcxx_function_requires(_ConvertibleConcept
<_ValueType2
,
160 typedef typename iterator_traits
<_ForwardIterator1
>::reference
162 typedef typename iterator_traits
<_ForwardIterator2
>::reference
164 std::__iter_swap
<__are_same
<_ValueType1
, _ValueType2
>::__value
&&
165 __are_same
<_ValueType1
&, _ReferenceType1
>::__value
&&
166 __are_same
<_ValueType2
&, _ReferenceType2
>::__value
>::
171 * @brief This does what you think it does.
172 * @param a A thing of arbitrary type.
173 * @param b Another thing of arbitrary type.
174 * @return The lesser of the parameters.
176 * This is the simple classic generic implementation. It will work on
177 * temporary expressions, since they are only evaluated once, unlike a
178 * preprocessor macro.
180 template<typename _Tp
>
182 min(const _Tp
& __a
, const _Tp
& __b
)
184 // concept requirements
185 __glibcxx_function_requires(_LessThanComparableConcept
<_Tp
>)
186 //return __b < __a ? __b : __a;
193 * @brief This does what you think it does.
194 * @param a A thing of arbitrary type.
195 * @param b Another thing of arbitrary type.
196 * @return The greater of the parameters.
198 * This is the simple classic generic implementation. It will work on
199 * temporary expressions, since they are only evaluated once, unlike a
200 * preprocessor macro.
202 template<typename _Tp
>
204 max(const _Tp
& __a
, const _Tp
& __b
)
206 // concept requirements
207 __glibcxx_function_requires(_LessThanComparableConcept
<_Tp
>)
208 //return __a < __b ? __b : __a;
215 * @brief This does what you think it does.
216 * @param a A thing of arbitrary type.
217 * @param b Another thing of arbitrary type.
218 * @param comp A @link s20_3_3_comparisons comparison functor@endlink.
219 * @return The lesser of the parameters.
221 * This will work on temporary expressions, since they are only evaluated
222 * once, unlike a preprocessor macro.
224 template<typename _Tp
, typename _Compare
>
226 min(const _Tp
& __a
, const _Tp
& __b
, _Compare __comp
)
228 //return __comp(__b, __a) ? __b : __a;
229 if (__comp(__b
, __a
))
235 * @brief This does what you think it does.
236 * @param a A thing of arbitrary type.
237 * @param b Another thing of arbitrary type.
238 * @param comp A @link s20_3_3_comparisons comparison functor@endlink.
239 * @return The greater of the parameters.
241 * This will work on temporary expressions, since they are only evaluated
242 * once, unlike a preprocessor macro.
244 template<typename _Tp
, typename _Compare
>
246 max(const _Tp
& __a
, const _Tp
& __b
, _Compare __comp
)
248 //return __comp(__a, __b) ? __b : __a;
249 if (__comp(__a
, __b
))
254 // All of these auxiliary structs serve two purposes. (1) Replace
255 // calls to copy with memmove whenever possible. (Memmove, not memcpy,
256 // because the input and output ranges are permitted to overlap.)
257 // (2) If we're using random access iterators, then write the loop as
258 // a for loop with an explicit count.
260 template<bool, typename
>
263 template<typename _II
, typename _OI
>
265 copy(_II __first
, _II __last
, _OI __result
)
267 for (; __first
!= __last
; ++__result
, ++__first
)
268 *__result
= *__first
;
273 template<bool _BoolType
>
274 struct __copy
<_BoolType
, random_access_iterator_tag
>
276 template<typename _II
, typename _OI
>
278 copy(_II __first
, _II __last
, _OI __result
)
280 typedef typename iterator_traits
<_II
>::difference_type _Distance
;
281 for(_Distance __n
= __last
- __first
; __n
> 0; --__n
)
283 *__result
= *__first
;
292 struct __copy
<true, random_access_iterator_tag
>
294 template<typename _Tp
>
296 copy(const _Tp
* __first
, const _Tp
* __last
, _Tp
* __result
)
298 std::memmove(__result
, __first
, sizeof(_Tp
) * (__last
- __first
));
299 return __result
+ (__last
- __first
);
303 template<typename _II
, typename _OI
>
305 __copy_aux(_II __first
, _II __last
, _OI __result
)
307 typedef typename iterator_traits
<_II
>::value_type _ValueTypeI
;
308 typedef typename iterator_traits
<_OI
>::value_type _ValueTypeO
;
309 typedef typename iterator_traits
<_II
>::iterator_category _Category
;
310 const bool __simple
= (__is_scalar
<_ValueTypeI
>::__value
311 && __is_pointer
<_II
>::__value
312 && __is_pointer
<_OI
>::__value
313 && __are_same
<_ValueTypeI
, _ValueTypeO
>::__value
);
315 return std::__copy
<__simple
, _Category
>::copy(__first
, __last
, __result
);
318 // Helpers for streambuf iterators (either istream or ostream).
319 template<typename _CharT
>
320 typename
__gnu_cxx::__enable_if
<__is_char
<_CharT
>::__value
,
321 ostreambuf_iterator
<_CharT
> >::__type
322 __copy_aux(_CharT
*, _CharT
*, ostreambuf_iterator
<_CharT
>);
324 template<typename _CharT
>
325 typename
__gnu_cxx::__enable_if
<__is_char
<_CharT
>::__value
,
326 ostreambuf_iterator
<_CharT
> >::__type
327 __copy_aux(const _CharT
*, const _CharT
*, ostreambuf_iterator
<_CharT
>);
329 template<typename _CharT
>
330 typename
__gnu_cxx::__enable_if
<__is_char
<_CharT
>::__value
, _CharT
*>::__type
331 __copy_aux(istreambuf_iterator
<_CharT
>, istreambuf_iterator
<_CharT
>,
337 template<typename _II
, typename _OI
>
339 __copy_n(_II __first
, _II __last
, _OI __result
)
340 { return std::__copy_aux(__first
, __last
, __result
); }
344 struct __copy_normal
<true, false>
346 template<typename _II
, typename _OI
>
348 __copy_n(_II __first
, _II __last
, _OI __result
)
349 { return std::__copy_aux(__first
.base(), __last
.base(), __result
); }
353 struct __copy_normal
<false, true>
355 template<typename _II
, typename _OI
>
357 __copy_n(_II __first
, _II __last
, _OI __result
)
358 { return _OI(std::__copy_aux(__first
, __last
, __result
.base())); }
362 struct __copy_normal
<true, true>
364 template<typename _II
, typename _OI
>
366 __copy_n(_II __first
, _II __last
, _OI __result
)
367 { return _OI(std::__copy_aux(__first
.base(), __last
.base(),
372 * @brief Copies the range [first,last) into result.
373 * @param first An input iterator.
374 * @param last An input iterator.
375 * @param result An output iterator.
376 * @return result + (first - last)
378 * This inline function will boil down to a call to @c memmove whenever
379 * possible. Failing that, if random access iterators are passed, then the
380 * loop count will be known (and therefore a candidate for compiler
381 * optimizations such as unrolling). Result may not be contained within
382 * [first,last); the copy_backward function should be used instead.
384 * Note that the end of the output range is permitted to be contained
385 * within [first,last).
387 template<typename _InputIterator
, typename _OutputIterator
>
388 inline _OutputIterator
389 copy(_InputIterator __first
, _InputIterator __last
,
390 _OutputIterator __result
)
392 // concept requirements
393 __glibcxx_function_requires(_InputIteratorConcept
<_InputIterator
>)
394 __glibcxx_function_requires(_OutputIteratorConcept
<_OutputIterator
,
395 typename iterator_traits
<_InputIterator
>::value_type
>)
396 __glibcxx_requires_valid_range(__first
, __last
);
398 const bool __in
= __is_normal_iterator
<_InputIterator
>::__value
;
399 const bool __out
= __is_normal_iterator
<_OutputIterator
>::__value
;
400 return std::__copy_normal
<__in
, __out
>::__copy_n(__first
, __last
,
404 // Overload for streambuf iterators.
405 template<typename _CharT
>
406 typename
__gnu_cxx::__enable_if
<__is_char
<_CharT
>::__value
,
407 ostreambuf_iterator
<_CharT
> >::__type
408 copy(istreambuf_iterator
<_CharT
>, istreambuf_iterator
<_CharT
>,
409 ostreambuf_iterator
<_CharT
>);
411 template<bool, typename
>
412 struct __copy_backward
414 template<typename _BI1
, typename _BI2
>
416 __copy_b(_BI1 __first
, _BI1 __last
, _BI2 __result
)
418 while (__first
!= __last
)
419 *--__result
= *--__last
;
424 template<bool _BoolType
>
425 struct __copy_backward
<_BoolType
, random_access_iterator_tag
>
427 template<typename _BI1
, typename _BI2
>
429 __copy_b(_BI1 __first
, _BI1 __last
, _BI2 __result
)
431 typename iterator_traits
<_BI1
>::difference_type __n
;
432 for (__n
= __last
- __first
; __n
> 0; --__n
)
433 *--__result
= *--__last
;
439 struct __copy_backward
<true, random_access_iterator_tag
>
441 template<typename _Tp
>
443 __copy_b(const _Tp
* __first
, const _Tp
* __last
, _Tp
* __result
)
445 const ptrdiff_t _Num
= __last
- __first
;
446 std::memmove(__result
- _Num
, __first
, sizeof(_Tp
) * _Num
);
447 return __result
- _Num
;
451 template<typename _BI1
, typename _BI2
>
453 __copy_backward_aux(_BI1 __first
, _BI1 __last
, _BI2 __result
)
455 typedef typename iterator_traits
<_BI1
>::value_type _ValueType1
;
456 typedef typename iterator_traits
<_BI2
>::value_type _ValueType2
;
457 typedef typename iterator_traits
<_BI1
>::iterator_category _Category
;
458 const bool __simple
= (__is_scalar
<_ValueType1
>::__value
459 && __is_pointer
<_BI1
>::__value
460 && __is_pointer
<_BI2
>::__value
461 && __are_same
<_ValueType1
, _ValueType2
>::__value
);
463 return std::__copy_backward
<__simple
, _Category
>::__copy_b(__first
,
469 struct __copy_backward_normal
471 template<typename _BI1
, typename _BI2
>
473 __copy_b_n(_BI1 __first
, _BI1 __last
, _BI2 __result
)
474 { return std::__copy_backward_aux(__first
, __last
, __result
); }
478 struct __copy_backward_normal
<true, false>
480 template<typename _BI1
, typename _BI2
>
482 __copy_b_n(_BI1 __first
, _BI1 __last
, _BI2 __result
)
483 { return std::__copy_backward_aux(__first
.base(), __last
.base(),
488 struct __copy_backward_normal
<false, true>
490 template<typename _BI1
, typename _BI2
>
492 __copy_b_n(_BI1 __first
, _BI1 __last
, _BI2 __result
)
493 { return _BI2(std::__copy_backward_aux(__first
, __last
,
498 struct __copy_backward_normal
<true, true>
500 template<typename _BI1
, typename _BI2
>
502 __copy_b_n(_BI1 __first
, _BI1 __last
, _BI2 __result
)
503 { return _BI2(std::__copy_backward_aux(__first
.base(), __last
.base(),
508 * @brief Copies the range [first,last) into result.
509 * @param first A bidirectional iterator.
510 * @param last A bidirectional iterator.
511 * @param result A bidirectional iterator.
512 * @return result - (first - last)
514 * The function has the same effect as copy, but starts at the end of the
515 * range and works its way to the start, returning the start of the result.
516 * This inline function will boil down to a call to @c memmove whenever
517 * possible. Failing that, if random access iterators are passed, then the
518 * loop count will be known (and therefore a candidate for compiler
519 * optimizations such as unrolling).
521 * Result may not be in the range [first,last). Use copy instead. Note
522 * that the start of the output range may overlap [first,last).
524 template <typename _BI1
, typename _BI2
>
526 copy_backward(_BI1 __first
, _BI1 __last
, _BI2 __result
)
528 // concept requirements
529 __glibcxx_function_requires(_BidirectionalIteratorConcept
<_BI1
>)
530 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept
<_BI2
>)
531 __glibcxx_function_requires(_ConvertibleConcept
<
532 typename iterator_traits
<_BI1
>::value_type
,
533 typename iterator_traits
<_BI2
>::value_type
>)
534 __glibcxx_requires_valid_range(__first
, __last
);
536 const bool __bi1
= __is_normal_iterator
<_BI1
>::__value
;
537 const bool __bi2
= __is_normal_iterator
<_BI2
>::__value
;
538 return std::__copy_backward_normal
<__bi1
, __bi2
>::__copy_b_n(__first
,
546 template<typename _ForwardIterator
, typename _Tp
>
548 fill(_ForwardIterator __first
, _ForwardIterator __last
,
551 for (; __first
!= __last
; ++__first
)
559 template<typename _ForwardIterator
, typename _Tp
>
561 fill(_ForwardIterator __first
, _ForwardIterator __last
,
564 const _Tp __tmp
= __value
;
565 for (; __first
!= __last
; ++__first
)
571 * @brief Fills the range [first,last) with copies of value.
572 * @param first A forward iterator.
573 * @param last A forward iterator.
574 * @param value A reference-to-const of arbitrary type.
577 * This function fills a range with copies of the same value. For one-byte
578 * types filling contiguous areas of memory, this becomes an inline call to
581 template<typename _ForwardIterator
, typename _Tp
>
583 fill(_ForwardIterator __first
, _ForwardIterator __last
, const _Tp
& __value
)
585 // concept requirements
586 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept
<
588 __glibcxx_requires_valid_range(__first
, __last
);
590 const bool __scalar
= __is_scalar
<_Tp
>::__value
;
591 std::__fill
<__scalar
>::fill(__first
, __last
, __value
);
594 // Specialization: for one-byte types we can use memset.
596 fill(unsigned char* __first
, unsigned char* __last
, const unsigned char& __c
)
598 __glibcxx_requires_valid_range(__first
, __last
);
599 const unsigned char __tmp
= __c
;
600 std::memset(__first
, __tmp
, __last
- __first
);
604 fill(signed char* __first
, signed char* __last
, const signed char& __c
)
606 __glibcxx_requires_valid_range(__first
, __last
);
607 const signed char __tmp
= __c
;
608 std::memset(__first
, static_cast<unsigned char>(__tmp
), __last
- __first
);
612 fill(char* __first
, char* __last
, const char& __c
)
614 __glibcxx_requires_valid_range(__first
, __last
);
615 const char __tmp
= __c
;
616 std::memset(__first
, static_cast<unsigned char>(__tmp
), __last
- __first
);
622 template<typename _OutputIterator
, typename _Size
, typename _Tp
>
623 static _OutputIterator
624 fill_n(_OutputIterator __first
, _Size __n
, const _Tp
& __value
)
626 for (; __n
> 0; --__n
, ++__first
)
633 struct __fill_n
<true>
635 template<typename _OutputIterator
, typename _Size
, typename _Tp
>
636 static _OutputIterator
637 fill_n(_OutputIterator __first
, _Size __n
, const _Tp
& __value
)
639 const _Tp __tmp
= __value
;
640 for (; __n
> 0; --__n
, ++__first
)
647 * @brief Fills the range [first,first+n) with copies of value.
648 * @param first An output iterator.
649 * @param n The count of copies to perform.
650 * @param value A reference-to-const of arbitrary type.
651 * @return The iterator at first+n.
653 * This function fills a range with copies of the same value. For one-byte
654 * types filling contiguous areas of memory, this becomes an inline call to
657 template<typename _OutputIterator
, typename _Size
, typename _Tp
>
659 fill_n(_OutputIterator __first
, _Size __n
, const _Tp
& __value
)
661 // concept requirements
662 __glibcxx_function_requires(_OutputIteratorConcept
<_OutputIterator
, _Tp
>)
664 const bool __scalar
= __is_scalar
<_Tp
>::__value
;
665 return std::__fill_n
<__scalar
>::fill_n(__first
, __n
, __value
);
668 template<typename _Size
>
669 inline unsigned char*
670 fill_n(unsigned char* __first
, _Size __n
, const unsigned char& __c
)
672 std::fill(__first
, __first
+ __n
, __c
);
673 return __first
+ __n
;
676 template<typename _Size
>
678 fill_n(signed char* __first
, _Size __n
, const signed char& __c
)
680 std::fill(__first
, __first
+ __n
, __c
);
681 return __first
+ __n
;
684 template<typename _Size
>
686 fill_n(char* __first
, _Size __n
, const char& __c
)
688 std::fill(__first
, __first
+ __n
, __c
);
689 return __first
+ __n
;
693 * @brief Finds the places in ranges which don't match.
694 * @param first1 An input iterator.
695 * @param last1 An input iterator.
696 * @param first2 An input iterator.
697 * @return A pair of iterators pointing to the first mismatch.
699 * This compares the elements of two ranges using @c == and returns a pair
700 * of iterators. The first iterator points into the first range, the
701 * second iterator points into the second range, and the elements pointed
702 * to by the iterators are not equal.
704 template<typename _InputIterator1
, typename _InputIterator2
>
705 pair
<_InputIterator1
, _InputIterator2
>
706 mismatch(_InputIterator1 __first1
, _InputIterator1 __last1
,
707 _InputIterator2 __first2
)
709 // concept requirements
710 __glibcxx_function_requires(_InputIteratorConcept
<_InputIterator1
>)
711 __glibcxx_function_requires(_InputIteratorConcept
<_InputIterator2
>)
712 __glibcxx_function_requires(_EqualOpConcept
<
713 typename iterator_traits
<_InputIterator1
>::value_type
,
714 typename iterator_traits
<_InputIterator2
>::value_type
>)
715 __glibcxx_requires_valid_range(__first1
, __last1
);
717 while (__first1
!= __last1
&& *__first1
== *__first2
)
722 return pair
<_InputIterator1
, _InputIterator2
>(__first1
, __first2
);
726 * @brief Finds the places in ranges which don't match.
727 * @param first1 An input iterator.
728 * @param last1 An input iterator.
729 * @param first2 An input iterator.
730 * @param binary_pred A binary predicate @link s20_3_1_base functor@endlink.
731 * @return A pair of iterators pointing to the first mismatch.
733 * This compares the elements of two ranges using the binary_pred
734 * parameter, and returns a pair
735 * of iterators. The first iterator points into the first range, the
736 * second iterator points into the second range, and the elements pointed
737 * to by the iterators are not equal.
739 template<typename _InputIterator1
, typename _InputIterator2
,
740 typename _BinaryPredicate
>
741 pair
<_InputIterator1
, _InputIterator2
>
742 mismatch(_InputIterator1 __first1
, _InputIterator1 __last1
,
743 _InputIterator2 __first2
, _BinaryPredicate __binary_pred
)
745 // concept requirements
746 __glibcxx_function_requires(_InputIteratorConcept
<_InputIterator1
>)
747 __glibcxx_function_requires(_InputIteratorConcept
<_InputIterator2
>)
748 __glibcxx_requires_valid_range(__first1
, __last1
);
750 while (__first1
!= __last1
&& __binary_pred(*__first1
, *__first2
))
755 return pair
<_InputIterator1
, _InputIterator2
>(__first1
, __first2
);
759 * @brief Tests a range for element-wise equality.
760 * @param first1 An input iterator.
761 * @param last1 An input iterator.
762 * @param first2 An input iterator.
763 * @return A boolean true or false.
765 * This compares the elements of two ranges using @c == and returns true or
766 * false depending on whether all of the corresponding elements of the
769 template<typename _InputIterator1
, typename _InputIterator2
>
771 equal(_InputIterator1 __first1
, _InputIterator1 __last1
,
772 _InputIterator2 __first2
)
774 // concept requirements
775 __glibcxx_function_requires(_InputIteratorConcept
<_InputIterator1
>)
776 __glibcxx_function_requires(_InputIteratorConcept
<_InputIterator2
>)
777 __glibcxx_function_requires(_EqualOpConcept
<
778 typename iterator_traits
<_InputIterator1
>::value_type
,
779 typename iterator_traits
<_InputIterator2
>::value_type
>)
780 __glibcxx_requires_valid_range(__first1
, __last1
);
782 for (; __first1
!= __last1
; ++__first1
, ++__first2
)
783 if (!(*__first1
== *__first2
))
789 * @brief Tests a range for element-wise equality.
790 * @param first1 An input iterator.
791 * @param last1 An input iterator.
792 * @param first2 An input iterator.
793 * @param binary_pred A binary predicate @link s20_3_1_base functor@endlink.
794 * @return A boolean true or false.
796 * This compares the elements of two ranges using the binary_pred
797 * parameter, and returns true or
798 * false depending on whether all of the corresponding elements of the
801 template<typename _InputIterator1
, typename _InputIterator2
,
802 typename _BinaryPredicate
>
804 equal(_InputIterator1 __first1
, _InputIterator1 __last1
,
805 _InputIterator2 __first2
,
806 _BinaryPredicate __binary_pred
)
808 // concept requirements
809 __glibcxx_function_requires(_InputIteratorConcept
<_InputIterator1
>)
810 __glibcxx_function_requires(_InputIteratorConcept
<_InputIterator2
>)
811 __glibcxx_requires_valid_range(__first1
, __last1
);
813 for (; __first1
!= __last1
; ++__first1
, ++__first2
)
814 if (!__binary_pred(*__first1
, *__first2
))
820 * @brief Performs "dictionary" comparison on ranges.
821 * @param first1 An input iterator.
822 * @param last1 An input iterator.
823 * @param first2 An input iterator.
824 * @param last2 An input iterator.
825 * @return A boolean true or false.
827 * "Returns true if the sequence of elements defined by the range
828 * [first1,last1) is lexicographically less than the sequence of elements
829 * defined by the range [first2,last2). Returns false otherwise."
830 * (Quoted from [25.3.8]/1.) If the iterators are all character pointers,
831 * then this is an inline call to @c memcmp.
833 template<typename _InputIterator1
, typename _InputIterator2
>
835 lexicographical_compare(_InputIterator1 __first1
, _InputIterator1 __last1
,
836 _InputIterator2 __first2
, _InputIterator2 __last2
)
838 // concept requirements
839 __glibcxx_function_requires(_InputIteratorConcept
<_InputIterator1
>)
840 __glibcxx_function_requires(_InputIteratorConcept
<_InputIterator2
>)
841 __glibcxx_function_requires(_LessThanOpConcept
<
842 typename iterator_traits
<_InputIterator1
>::value_type
,
843 typename iterator_traits
<_InputIterator2
>::value_type
>)
844 __glibcxx_function_requires(_LessThanOpConcept
<
845 typename iterator_traits
<_InputIterator2
>::value_type
,
846 typename iterator_traits
<_InputIterator1
>::value_type
>)
847 __glibcxx_requires_valid_range(__first1
, __last1
);
848 __glibcxx_requires_valid_range(__first2
, __last2
);
850 for (; __first1
!= __last1
&& __first2
!= __last2
;
851 ++__first1
, ++__first2
)
853 if (*__first1
< *__first2
)
855 if (*__first2
< *__first1
)
858 return __first1
== __last1
&& __first2
!= __last2
;
862 * @brief Performs "dictionary" comparison on ranges.
863 * @param first1 An input iterator.
864 * @param last1 An input iterator.
865 * @param first2 An input iterator.
866 * @param last2 An input iterator.
867 * @param comp A @link s20_3_3_comparisons comparison functor@endlink.
868 * @return A boolean true or false.
870 * The same as the four-parameter @c lexigraphical_compare, but uses the
871 * comp parameter instead of @c <.
873 template<typename _InputIterator1
, typename _InputIterator2
,
876 lexicographical_compare(_InputIterator1 __first1
, _InputIterator1 __last1
,
877 _InputIterator2 __first2
, _InputIterator2 __last2
,
880 // concept requirements
881 __glibcxx_function_requires(_InputIteratorConcept
<_InputIterator1
>)
882 __glibcxx_function_requires(_InputIteratorConcept
<_InputIterator2
>)
883 __glibcxx_requires_valid_range(__first1
, __last1
);
884 __glibcxx_requires_valid_range(__first2
, __last2
);
886 for (; __first1
!= __last1
&& __first2
!= __last2
;
887 ++__first1
, ++__first2
)
889 if (__comp(*__first1
, *__first2
))
891 if (__comp(*__first2
, *__first1
))
894 return __first1
== __last1
&& __first2
!= __last2
;
898 lexicographical_compare(const unsigned char* __first1
,
899 const unsigned char* __last1
,
900 const unsigned char* __first2
,
901 const unsigned char* __last2
)
903 __glibcxx_requires_valid_range(__first1
, __last1
);
904 __glibcxx_requires_valid_range(__first2
, __last2
);
906 const size_t __len1
= __last1
- __first1
;
907 const size_t __len2
= __last2
- __first2
;
908 const int __result
= std::memcmp(__first1
, __first2
,
909 std::min(__len1
, __len2
));
910 return __result
!= 0 ? __result
< 0 : __len1
< __len2
;
914 lexicographical_compare(const char* __first1
, const char* __last1
,
915 const char* __first2
, const char* __last2
)
917 __glibcxx_requires_valid_range(__first1
, __last1
);
918 __glibcxx_requires_valid_range(__first2
, __last2
);
920 #if CHAR_MAX == SCHAR_MAX
921 return std::lexicographical_compare((const signed char*) __first1
,
922 (const signed char*) __last1
,
923 (const signed char*) __first2
,
924 (const signed char*) __last2
);
925 #else /* CHAR_MAX == SCHAR_MAX */
926 return std::lexicographical_compare((const unsigned char*) __first1
,
927 (const unsigned char*) __last1
,
928 (const unsigned char*) __first2
,
929 (const unsigned char*) __last2
);
930 #endif /* CHAR_MAX == SCHAR_MAX */
933 _GLIBCXX_END_NAMESPACE