stl_algobase.h

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00001 // Core algorithmic facilities -*- C++ -*-
00002 
00003 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007
00004 // Free Software Foundation, Inc.
00005 //
00006 // This file is part of the GNU ISO C++ Library.  This library is free
00007 // software; you can redistribute it and/or modify it under the
00008 // terms of the GNU General Public License as published by the
00009 // Free Software Foundation; either version 2, or (at your option)
00010 // any later version.
00011 
00012 // This library is distributed in the hope that it will be useful,
00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015 // GNU General Public License for more details.
00016 
00017 // You should have received a copy of the GNU General Public License along
00018 // with this library; see the file COPYING.  If not, write to the Free
00019 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
00020 // USA.
00021 
00022 // As a special exception, you may use this file as part of a free software
00023 // library without restriction.  Specifically, if other files instantiate
00024 // templates or use macros or inline functions from this file, or you compile
00025 // this file and link it with other files to produce an executable, this
00026 // file does not by itself cause the resulting executable to be covered by
00027 // the GNU General Public License.  This exception does not however
00028 // invalidate any other reasons why the executable file might be covered by
00029 // the GNU General Public License.
00030 
00031 /*
00032  *
00033  * Copyright (c) 1994
00034  * Hewlett-Packard Company
00035  *
00036  * Permission to use, copy, modify, distribute and sell this software
00037  * and its documentation for any purpose is hereby granted without fee,
00038  * provided that the above copyright notice appear in all copies and
00039  * that both that copyright notice and this permission notice appear
00040  * in supporting documentation.  Hewlett-Packard Company makes no
00041  * representations about the suitability of this software for any
00042  * purpose.  It is provided "as is" without express or implied warranty.
00043  *
00044  *
00045  * Copyright (c) 1996-1998
00046  * Silicon Graphics Computer Systems, Inc.
00047  *
00048  * Permission to use, copy, modify, distribute and sell this software
00049  * and its documentation for any purpose is hereby granted without fee,
00050  * provided that the above copyright notice appear in all copies and
00051  * that both that copyright notice and this permission notice appear
00052  * in supporting documentation.  Silicon Graphics makes no
00053  * representations about the suitability of this software for any
00054  * purpose.  It is provided "as is" without express or implied warranty.
00055  */
00056 
00057 /** @file stl_algobase.h
00058  *  This is an internal header file, included by other library headers.
00059  *  You should not attempt to use it directly.
00060  */
00061 
00062 #ifndef _STL_ALGOBASE_H
00063 #define _STL_ALGOBASE_H 1
00064 
00065 #include <bits/c++config.h>
00066 #include <cstddef>
00067 #include <bits/functexcept.h>
00068 #include <bits/cpp_type_traits.h>
00069 #include <ext/type_traits.h>
00070 #include <ext/numeric_traits.h>
00071 #include <bits/stl_pair.h>
00072 #include <bits/stl_iterator_base_types.h>
00073 #include <bits/stl_iterator_base_funcs.h>
00074 #include <bits/stl_iterator.h>
00075 #include <bits/concept_check.h>
00076 #include <debug/debug.h>
00077 #include <bits/stl_move.h> // For std::swap and _GLIBCXX_MOVE
00078 
00079 _GLIBCXX_BEGIN_NAMESPACE(std)
00080 
00081   // See http://gcc.gnu.org/ml/libstdc++/2004-08/msg00167.html: in a
00082   // nutshell, we are partially implementing the resolution of DR 187,
00083   // when it's safe, i.e., the value_types are equal.
00084   template<bool _BoolType>
00085     struct __iter_swap
00086     {
00087       template<typename _ForwardIterator1, typename _ForwardIterator2>
00088         static void
00089         iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b)
00090         {
00091           typedef typename iterator_traits<_ForwardIterator1>::value_type
00092             _ValueType1;
00093           _ValueType1 __tmp = _GLIBCXX_MOVE(*__a);
00094           *__a = _GLIBCXX_MOVE(*__b);
00095           *__b = _GLIBCXX_MOVE(__tmp);
00096     }
00097     };
00098 
00099   template<>
00100     struct __iter_swap<true>
00101     {
00102       template<typename _ForwardIterator1, typename _ForwardIterator2>
00103         static void 
00104         iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b)
00105         {
00106           swap(*__a, *__b);
00107         }
00108     };
00109 
00110   /**
00111    *  @brief Swaps the contents of two iterators.
00112    *  @param  a  An iterator.
00113    *  @param  b  Another iterator.
00114    *  @return   Nothing.
00115    *
00116    *  This function swaps the values pointed to by two iterators, not the
00117    *  iterators themselves.
00118   */
00119   template<typename _ForwardIterator1, typename _ForwardIterator2>
00120     inline void
00121     iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b)
00122     {
00123       typedef typename iterator_traits<_ForwardIterator1>::value_type
00124     _ValueType1;
00125       typedef typename iterator_traits<_ForwardIterator2>::value_type
00126     _ValueType2;
00127 
00128       // concept requirements
00129       __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
00130                   _ForwardIterator1>)
00131       __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
00132                   _ForwardIterator2>)
00133       __glibcxx_function_requires(_ConvertibleConcept<_ValueType1,
00134                   _ValueType2>)
00135       __glibcxx_function_requires(_ConvertibleConcept<_ValueType2,
00136                   _ValueType1>)
00137 
00138       typedef typename iterator_traits<_ForwardIterator1>::reference
00139     _ReferenceType1;
00140       typedef typename iterator_traits<_ForwardIterator2>::reference
00141     _ReferenceType2;
00142       std::__iter_swap<__are_same<_ValueType1, _ValueType2>::__value
00143     && __are_same<_ValueType1&, _ReferenceType1>::__value
00144     && __are_same<_ValueType2&, _ReferenceType2>::__value>::
00145 	iter_swap(__a, __b);
00146     }
00147 
00148   /**
00149    *  @brief Swap the elements of two sequences.
00150    *  @param  first1  A forward iterator.
00151    *  @param  last1   A forward iterator.
00152    *  @param  first2  A forward iterator.
00153    *  @return   An iterator equal to @p first2+(last1-first1).
00154    *
00155    *  Swaps each element in the range @p [first1,last1) with the
00156    *  corresponding element in the range @p [first2,(last1-first1)).
00157    *  The ranges must not overlap.
00158   */
00159   template<typename _ForwardIterator1, typename _ForwardIterator2>
00160     _ForwardIterator2
00161     swap_ranges(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
00162         _ForwardIterator2 __first2)
00163     {
00164       // concept requirements
00165       __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
00166                   _ForwardIterator1>)
00167       __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
00168                   _ForwardIterator2>)
00169       __glibcxx_requires_valid_range(__first1, __last1);
00170 
00171       for (; __first1 != __last1; ++__first1, ++__first2)
00172     std::iter_swap(__first1, __first2);
00173       return __first2;
00174     }
00175 
00176   /**
00177    *  @brief This does what you think it does.
00178    *  @param  a  A thing of arbitrary type.
00179    *  @param  b  Another thing of arbitrary type.
00180    *  @return   The lesser of the parameters.
00181    *
00182    *  This is the simple classic generic implementation.  It will work on
00183    *  temporary expressions, since they are only evaluated once, unlike a
00184    *  preprocessor macro.
00185   */
00186   template<typename _Tp>
00187     inline const _Tp&
00188     min(const _Tp& __a, const _Tp& __b)
00189     {
00190       // concept requirements
00191       __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
00192       //return __b < __a ? __b : __a;
00193       if (__b < __a)
00194     return __b;
00195       return __a;
00196     }
00197 
00198   /**
00199    *  @brief This does what you think it does.
00200    *  @param  a  A thing of arbitrary type.
00201    *  @param  b  Another thing of arbitrary type.
00202    *  @return   The greater of the parameters.
00203    *
00204    *  This is the simple classic generic implementation.  It will work on
00205    *  temporary expressions, since they are only evaluated once, unlike a
00206    *  preprocessor macro.
00207   */
00208   template<typename _Tp>
00209     inline const _Tp&
00210     max(const _Tp& __a, const _Tp& __b)
00211     {
00212       // concept requirements
00213       __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
00214       //return  __a < __b ? __b : __a;
00215       if (__a < __b)
00216     return __b;
00217       return __a;
00218     }
00219 
00220   /**
00221    *  @brief This does what you think it does.
00222    *  @param  a  A thing of arbitrary type.
00223    *  @param  b  Another thing of arbitrary type.
00224    *  @param  comp  A @link s20_3_3_comparisons comparison functor@endlink.
00225    *  @return   The lesser of the parameters.
00226    *
00227    *  This will work on temporary expressions, since they are only evaluated
00228    *  once, unlike a preprocessor macro.
00229   */
00230   template<typename _Tp, typename _Compare>
00231     inline const _Tp&
00232     min(const _Tp& __a, const _Tp& __b, _Compare __comp)
00233     {
00234       //return __comp(__b, __a) ? __b : __a;
00235       if (__comp(__b, __a))
00236     return __b;
00237       return __a;
00238     }
00239 
00240   /**
00241    *  @brief This does what you think it does.
00242    *  @param  a  A thing of arbitrary type.
00243    *  @param  b  Another thing of arbitrary type.
00244    *  @param  comp  A @link s20_3_3_comparisons comparison functor@endlink.
00245    *  @return   The greater of the parameters.
00246    *
00247    *  This will work on temporary expressions, since they are only evaluated
00248    *  once, unlike a preprocessor macro.
00249   */
00250   template<typename _Tp, typename _Compare>
00251     inline const _Tp&
00252     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
00253     {
00254       //return __comp(__a, __b) ? __b : __a;
00255       if (__comp(__a, __b))
00256     return __b;
00257       return __a;
00258     }
00259 
00260 
00261   // If _Iterator is a __normal_iterator return its base (a plain pointer,
00262   // normally) otherwise return it untouched.  See copy, fill, ... 
00263   template<typename _Iterator,
00264        bool _IsNormal = __is_normal_iterator<_Iterator>::__value>
00265     struct __niter_base
00266     {
00267       static _Iterator
00268       __b(_Iterator __it)
00269       { return __it; }
00270     };
00271 
00272   template<typename _Iterator>
00273     struct __niter_base<_Iterator, true>
00274     {
00275       static typename _Iterator::iterator_type
00276       __b(_Iterator __it)
00277       { return __it.base(); }
00278     };
00279 
00280   // Likewise, for move_iterator.
00281   template<typename _Iterator,
00282        bool _IsMove = __is_move_iterator<_Iterator>::__value>
00283     struct __miter_base
00284     {
00285       static _Iterator
00286       __b(_Iterator __it)
00287       { return __it; }
00288     };
00289 
00290   template<typename _Iterator>
00291     struct __miter_base<_Iterator, true>
00292     {
00293       static typename _Iterator::iterator_type
00294       __b(_Iterator __it)
00295       { return __it.base(); }
00296     };
00297 
00298   // All of these auxiliary structs serve two purposes.  (1) Replace
00299   // calls to copy with memmove whenever possible.  (Memmove, not memcpy,
00300   // because the input and output ranges are permitted to overlap.)
00301   // (2) If we're using random access iterators, then write the loop as
00302   // a for loop with an explicit count.
00303 
00304   template<bool, bool, typename>
00305     struct __copy_move
00306     {
00307       template<typename _II, typename _OI>
00308         static _OI
00309         __copy_m(_II __first, _II __last, _OI __result)
00310         {
00311       for (; __first != __last; ++__result, ++__first)
00312         *__result = *__first;
00313       return __result;
00314     }
00315     };
00316 
00317 #ifdef __GXX_EXPERIMENTAL_CXX0X__
00318   template<typename _Category>
00319     struct __copy_move<true, false, _Category>
00320     {
00321       template<typename _II, typename _OI>
00322         static _OI
00323         __copy_m(_II __first, _II __last, _OI __result)
00324         {
00325       for (; __first != __last; ++__result, ++__first)
00326         *__result = std::move(*__first);
00327       return __result;
00328     }
00329     };
00330 #endif
00331 
00332   template<>
00333     struct __copy_move<false, false, random_access_iterator_tag>
00334     {
00335       template<typename _II, typename _OI>
00336         static _OI
00337         __copy_m(_II __first, _II __last, _OI __result)
00338         { 
00339       typedef typename iterator_traits<_II>::difference_type _Distance;
00340       for(_Distance __n = __last - __first; __n > 0; --__n)
00341         {
00342           *__result = *__first;
00343           ++__first;
00344           ++__result;
00345         }
00346       return __result;
00347     }
00348     };
00349 
00350 #ifdef __GXX_EXPERIMENTAL_CXX0X__
00351   template<>
00352     struct __copy_move<true, false, random_access_iterator_tag>
00353     {
00354       template<typename _II, typename _OI>
00355         static _OI
00356         __copy_m(_II __first, _II __last, _OI __result)
00357         { 
00358       typedef typename iterator_traits<_II>::difference_type _Distance;
00359       for(_Distance __n = __last - __first; __n > 0; --__n)
00360         {
00361           *__result = std::move(*__first);
00362           ++__first;
00363           ++__result;
00364         }
00365       return __result;
00366     }
00367     };
00368 #endif
00369 
00370   template<bool _IsMove>
00371     struct __copy_move<_IsMove, true, random_access_iterator_tag>
00372     {
00373       template<typename _Tp>
00374         static _Tp*
00375         __copy_m(const _Tp* __first, const _Tp* __last, _Tp* __result)
00376         {
00377       __builtin_memmove(__result, __first,
00378                 sizeof(_Tp) * (__last - __first));
00379       return __result + (__last - __first);
00380     }
00381     };
00382 
00383   template<bool _IsMove, typename _II, typename _OI>
00384     inline _OI
00385     __copy_move_a(_II __first, _II __last, _OI __result)
00386     {
00387       typedef typename iterator_traits<_II>::value_type _ValueTypeI;
00388       typedef typename iterator_traits<_OI>::value_type _ValueTypeO;
00389       typedef typename iterator_traits<_II>::iterator_category _Category;
00390       const bool __simple = (__is_pod(_ValueTypeI)
00391                          && __is_pointer<_II>::__value
00392                          && __is_pointer<_OI>::__value
00393                  && __are_same<_ValueTypeI, _ValueTypeO>::__value);
00394 
00395       return std::__copy_move<_IsMove, __simple,
00396                           _Category>::__copy_m(__first, __last, __result);
00397     }
00398 
00399   // Helpers for streambuf iterators (either istream or ostream).
00400   // NB: avoid including <iosfwd>, relatively large.
00401   template<typename _CharT>
00402     struct char_traits;
00403 
00404   template<typename _CharT, typename _Traits>
00405     class istreambuf_iterator;
00406 
00407   template<typename _CharT, typename _Traits>
00408     class ostreambuf_iterator;
00409 
00410   template<bool _IsMove, typename _CharT>
00411     typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, 
00412          ostreambuf_iterator<_CharT, char_traits<_CharT> > >::__type
00413     __copy_move_a2(_CharT*, _CharT*,
00414            ostreambuf_iterator<_CharT, char_traits<_CharT> >);
00415 
00416   template<bool _IsMove, typename _CharT>
00417     typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, 
00418          ostreambuf_iterator<_CharT, char_traits<_CharT> > >::__type
00419     __copy_move_a2(const _CharT*, const _CharT*,
00420            ostreambuf_iterator<_CharT, char_traits<_CharT> >);
00421 
00422   template<bool _IsMove, typename _CharT>
00423     typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
00424                     _CharT*>::__type
00425     __copy_move_a2(istreambuf_iterator<_CharT, char_traits<_CharT> >,
00426            istreambuf_iterator<_CharT, char_traits<_CharT> >, _CharT*);
00427 
00428   template<bool _IsMove, typename _II, typename _OI>
00429     inline _OI
00430     __copy_move_a2(_II __first, _II __last, _OI __result)
00431     {
00432       return _OI(std::__copy_move_a<_IsMove>
00433          (std::__niter_base<_II>::__b(__first),
00434           std::__niter_base<_II>::__b(__last),
00435           std::__niter_base<_OI>::__b(__result)));
00436     }
00437 
00438   /**
00439    *  @brief Copies the range [first,last) into result.
00440    *  @param  first  An input iterator.
00441    *  @param  last   An input iterator.
00442    *  @param  result An output iterator.
00443    *  @return   result + (first - last)
00444    *
00445    *  This inline function will boil down to a call to @c memmove whenever
00446    *  possible.  Failing that, if random access iterators are passed, then the
00447    *  loop count will be known (and therefore a candidate for compiler
00448    *  optimizations such as unrolling).  Result may not be contained within
00449    *  [first,last); the copy_backward function should be used instead.
00450    *
00451    *  Note that the end of the output range is permitted to be contained
00452    *  within [first,last).
00453   */
00454   template<typename _II, typename _OI>
00455     inline _OI
00456     copy(_II __first, _II __last, _OI __result)
00457     {
00458       // concept requirements
00459       __glibcxx_function_requires(_InputIteratorConcept<_II>)
00460       __glibcxx_function_requires(_OutputIteratorConcept<_OI,
00461         typename iterator_traits<_II>::value_type>)
00462       __glibcxx_requires_valid_range(__first, __last);
00463 
00464       return (std::__copy_move_a2<__is_move_iterator<_II>::__value>
00465           (std::__miter_base<_II>::__b(__first),
00466            std::__miter_base<_II>::__b(__last), __result));
00467     }
00468 
00469 #ifdef __GXX_EXPERIMENTAL_CXX0X__
00470   /**
00471    *  @brief Moves the range [first,last) into result.
00472    *  @param  first  An input iterator.
00473    *  @param  last   An input iterator.
00474    *  @param  result An output iterator.
00475    *  @return   result + (first - last)
00476    *
00477    *  This inline function will boil down to a call to @c memmove whenever
00478    *  possible.  Failing that, if random access iterators are passed, then the
00479    *  loop count will be known (and therefore a candidate for compiler
00480    *  optimizations such as unrolling).  Result may not be contained within
00481    *  [first,last); the move_backward function should be used instead.
00482    *
00483    *  Note that the end of the output range is permitted to be contained
00484    *  within [first,last).
00485   */
00486   template<typename _II, typename _OI>
00487     inline _OI
00488     move(_II __first, _II __last, _OI __result)
00489     {
00490       // concept requirements
00491       __glibcxx_function_requires(_InputIteratorConcept<_II>)
00492       __glibcxx_function_requires(_OutputIteratorConcept<_OI,
00493         typename iterator_traits<_II>::value_type>)
00494       __glibcxx_requires_valid_range(__first, __last);
00495 
00496       return (std::__copy_move_a2<true>
00497           (std::__miter_base<_II>::__b(__first),
00498            std::__miter_base<_II>::__b(__last), __result));
00499     }
00500 
00501 #define _GLIBCXX_MOVE3(_Tp, _Up, _Vp) std::move(_Tp, _Up, _Vp)
00502 #else
00503 #define _GLIBCXX_MOVE3(_Tp, _Up, _Vp) std::copy(_Tp, _Up, _Vp)
00504 #endif
00505 
00506   template<bool, bool, typename>
00507     struct __copy_move_backward
00508     {
00509       template<typename _BI1, typename _BI2>
00510         static _BI2
00511         __copy_move_b(_BI1 __first, _BI1 __last, _BI2 __result)
00512         {
00513       while (__first != __last)
00514         *--__result = *--__last;
00515       return __result;
00516     }
00517     };
00518 
00519 #ifdef __GXX_EXPERIMENTAL_CXX0X__
00520   template<typename _Category>
00521     struct __copy_move_backward<true, false, _Category>
00522     {
00523       template<typename _BI1, typename _BI2>
00524         static _BI2
00525         __copy_move_b(_BI1 __first, _BI1 __last, _BI2 __result)
00526         {
00527       while (__first != __last)
00528         *--__result = std::move(*--__last);
00529       return __result;
00530     }
00531     };
00532 #endif
00533 
00534   template<>
00535     struct __copy_move_backward<false, false, random_access_iterator_tag>
00536     {
00537       template<typename _BI1, typename _BI2>
00538         static _BI2
00539         __copy_move_b(_BI1 __first, _BI1 __last, _BI2 __result)
00540         {
00541       typename iterator_traits<_BI1>::difference_type __n;
00542       for (__n = __last - __first; __n > 0; --__n)
00543         *--__result = *--__last;
00544       return __result;
00545     }
00546     };
00547 
00548 #ifdef __GXX_EXPERIMENTAL_CXX0X__
00549   template<>
00550     struct __copy_move_backward<true, false, random_access_iterator_tag>
00551     {
00552       template<typename _BI1, typename _BI2>
00553         static _BI2
00554         __copy_move_b(_BI1 __first, _BI1 __last, _BI2 __result)
00555         {
00556       typename iterator_traits<_BI1>::difference_type __n;
00557       for (__n = __last - __first; __n > 0; --__n)
00558         *--__result = std::move(*--__last);
00559       return __result;
00560     }
00561     };
00562 #endif
00563 
00564   template<bool _IsMove>
00565     struct __copy_move_backward<_IsMove, true, random_access_iterator_tag>
00566     {
00567       template<typename _Tp>
00568         static _Tp*
00569         __copy_move_b(const _Tp* __first, const _Tp* __last, _Tp* __result)
00570         {
00571       const ptrdiff_t _Num = __last - __first;
00572       __builtin_memmove(__result - _Num, __first, sizeof(_Tp) * _Num);
00573       return __result - _Num;
00574     }
00575     };
00576 
00577   template<bool _IsMove, typename _BI1, typename _BI2>
00578     inline _BI2
00579     __copy_move_backward_a(_BI1 __first, _BI1 __last, _BI2 __result)
00580     {
00581       typedef typename iterator_traits<_BI1>::value_type _ValueType1;
00582       typedef typename iterator_traits<_BI2>::value_type _ValueType2;
00583       typedef typename iterator_traits<_BI1>::iterator_category _Category;
00584       const bool __simple = (__is_pod(_ValueType1)
00585                          && __is_pointer<_BI1>::__value
00586                          && __is_pointer<_BI2>::__value
00587                  && __are_same<_ValueType1, _ValueType2>::__value);
00588 
00589       return std::__copy_move_backward<_IsMove, __simple,
00590                                    _Category>::__copy_move_b(__first,
00591                                  __last,
00592                                  __result);
00593     }
00594 
00595   template<bool _IsMove, typename _BI1, typename _BI2>
00596     inline _BI2
00597     __copy_move_backward_a2(_BI1 __first, _BI1 __last, _BI2 __result)
00598     {
00599       return _BI2(std::__copy_move_backward_a<_IsMove>
00600           (std::__niter_base<_BI1>::__b(__first),
00601            std::__niter_base<_BI1>::__b(__last),
00602            std::__niter_base<_BI2>::__b(__result)));
00603     }
00604 
00605   /**
00606    *  @brief Copies the range [first,last) into result.
00607    *  @param  first  A bidirectional iterator.
00608    *  @param  last   A bidirectional iterator.
00609    *  @param  result A bidirectional iterator.
00610    *  @return   result - (first - last)
00611    *
00612    *  The function has the same effect as copy, but starts at the end of the
00613    *  range and works its way to the start, returning the start of the result.
00614    *  This inline function will boil down to a call to @c memmove whenever
00615    *  possible.  Failing that, if random access iterators are passed, then the
00616    *  loop count will be known (and therefore a candidate for compiler
00617    *  optimizations such as unrolling).
00618    *
00619    *  Result may not be in the range [first,last).  Use copy instead.  Note
00620    *  that the start of the output range may overlap [first,last).
00621   */
00622   template<typename _BI1, typename _BI2>
00623     inline _BI2
00624     copy_backward(_BI1 __first, _BI1 __last, _BI2 __result)
00625     {
00626       // concept requirements
00627       __glibcxx_function_requires(_BidirectionalIteratorConcept<_BI1>)
00628       __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<_BI2>)
00629       __glibcxx_function_requires(_ConvertibleConcept<
00630         typename iterator_traits<_BI1>::value_type,
00631         typename iterator_traits<_BI2>::value_type>)
00632       __glibcxx_requires_valid_range(__first, __last);
00633 
00634       return (std::__copy_move_backward_a2<__is_move_iterator<_BI1>::__value>
00635           (std::__miter_base<_BI1>::__b(__first),
00636            std::__miter_base<_BI1>::__b(__last), __result));
00637     }
00638 
00639 #ifdef __GXX_EXPERIMENTAL_CXX0X__
00640   /**
00641    *  @brief Moves the range [first,last) into result.
00642    *  @param  first  A bidirectional iterator.
00643    *  @param  last   A bidirectional iterator.
00644    *  @param  result A bidirectional iterator.
00645    *  @return   result - (first - last)
00646    *
00647    *  The function has the same effect as move, but starts at the end of the
00648    *  range and works its way to the start, returning the start of the result.
00649    *  This inline function will boil down to a call to @c memmove whenever
00650    *  possible.  Failing that, if random access iterators are passed, then the
00651    *  loop count will be known (and therefore a candidate for compiler
00652    *  optimizations such as unrolling).
00653    *
00654    *  Result may not be in the range [first,last).  Use move instead.  Note
00655    *  that the start of the output range may overlap [first,last).
00656   */
00657   template<typename _BI1, typename _BI2>
00658     inline _BI2
00659     move_backward(_BI1 __first, _BI1 __last, _BI2 __result)
00660     {
00661       // concept requirements
00662       __glibcxx_function_requires(_BidirectionalIteratorConcept<_BI1>)
00663       __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<_BI2>)
00664       __glibcxx_function_requires(_ConvertibleConcept<
00665         typename iterator_traits<_BI1>::value_type,
00666         typename iterator_traits<_BI2>::value_type>)
00667       __glibcxx_requires_valid_range(__first, __last);
00668 
00669       return (std::__copy_move_backward_a2<true>
00670           (std::__miter_base<_BI1>::__b(__first),
00671            std::__miter_base<_BI1>::__b(__last), __result));
00672     }
00673 
00674 #define _GLIBCXX_MOVE_BACKWARD3(_Tp, _Up, _Vp) std::move_backward(_Tp, _Up, _Vp)
00675 #else
00676 #define _GLIBCXX_MOVE_BACKWARD3(_Tp, _Up, _Vp) std::copy_backward(_Tp, _Up, _Vp)
00677 #endif
00678 
00679   template<typename _ForwardIterator, typename _Tp>
00680     inline typename
00681     __gnu_cxx::__enable_if<!__is_scalar<_Tp>::__value, void>::__type
00682     __fill_a(_ForwardIterator __first, _ForwardIterator __last,
00683          const _Tp& __value)
00684     {
00685       for (; __first != __last; ++__first)
00686     *__first = __value;
00687     }
00688     
00689   template<typename _ForwardIterator, typename _Tp>
00690     inline typename
00691     __gnu_cxx::__enable_if<__is_scalar<_Tp>::__value, void>::__type
00692     __fill_a(_ForwardIterator __first, _ForwardIterator __last, _Tp __value)
00693     {
00694       for (; __first != __last; ++__first)
00695     *__first = __value;
00696     }
00697 
00698   // Specialization: for char types we can use memset.
00699   template<typename _Tp>
00700     inline typename
00701     __gnu_cxx::__enable_if<__is_byte<_Tp>::__value, void>::__type
00702     __fill_a(_Tp* __first, _Tp* __last, _Tp __c)
00703     { __builtin_memset(__first, static_cast<unsigned char>(__c),
00704                __last - __first); }
00705 
00706   /**
00707    *  @brief Fills the range [first,last) with copies of value.
00708    *  @param  first  A forward iterator.
00709    *  @param  last   A forward iterator.
00710    *  @param  value  A reference-to-const of arbitrary type.
00711    *  @return   Nothing.
00712    *
00713    *  This function fills a range with copies of the same value.  For char
00714    *  types filling contiguous areas of memory, this becomes an inline call
00715    *  to @c memset or @c wmemset.
00716   */
00717   template<typename _ForwardIterator, typename _Tp>
00718     inline void
00719     fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value)
00720     {
00721       // concept requirements
00722       __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
00723                   _ForwardIterator>)
00724       __glibcxx_requires_valid_range(__first, __last);
00725 
00726       std::__fill_a(std::__niter_base<_ForwardIterator>::__b(__first),
00727             std::__niter_base<_ForwardIterator>::__b(__last), __value);
00728     }
00729 
00730   template<typename _OutputIterator, typename _Size, typename _Tp>
00731     inline typename
00732     __gnu_cxx::__enable_if<!__is_scalar<_Tp>::__value, _OutputIterator>::__type
00733     __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value)
00734     {
00735       for (; __n > 0; --__n, ++__first)
00736     *__first = __value;
00737       return __first;
00738     }
00739 
00740   template<typename _OutputIterator, typename _Size, typename _Tp>
00741     inline typename
00742     __gnu_cxx::__enable_if<__is_scalar<_Tp>::__value, _OutputIterator>::__type
00743     __fill_n_a(_OutputIterator __first, _Size __n, _Tp __value)
00744     {
00745       for (; __n > 0; --__n, ++__first)
00746     *__first = __value;
00747       return __first;
00748     }
00749 
00750   template<typename _Size, typename _Tp>
00751     inline typename
00752     __gnu_cxx::__enable_if<__is_byte<_Tp>::__value, _Tp*>::__type
00753     __fill_n_a(_Tp* __first, _Size __n, _Tp __c)
00754     {
00755       std::__fill_a(__first, __first + __n, __c);
00756       return __first + __n;
00757     }
00758 
00759   /**
00760    *  @brief Fills the range [first,first+n) with copies of value.
00761    *  @param  first  An output iterator.
00762    *  @param  n      The count of copies to perform.
00763    *  @param  value  A reference-to-const of arbitrary type.
00764    *  @return   The iterator at first+n.
00765    *
00766    *  This function fills a range with copies of the same value.  For char
00767    *  types filling contiguous areas of memory, this becomes an inline call
00768    *  to @c memset or @ wmemset.
00769   */
00770   template<typename _OI, typename _Size, typename _Tp>
00771     inline _OI
00772     fill_n(_OI __first, _Size __n, const _Tp& __value)
00773     {
00774       // concept requirements
00775       __glibcxx_function_requires(_OutputIteratorConcept<_OI, _Tp>)
00776 
00777       return _OI(std::__fill_n_a(std::__niter_base<_OI>::__b(__first),
00778                  __n, __value));
00779     }
00780 
00781   template<bool _BoolType>
00782     struct __equal
00783     {
00784       template<typename _II1, typename _II2>
00785         static bool
00786         equal(_II1 __first1, _II1 __last1, _II2 __first2)
00787         {
00788       for (; __first1 != __last1; ++__first1, ++__first2)
00789         if (!(*__first1 == *__first2))
00790           return false;
00791       return true;
00792     }
00793     };
00794 
00795   template<>
00796     struct __equal<true>
00797     {
00798       template<typename _Tp>
00799         static bool
00800         equal(const _Tp* __first1, const _Tp* __last1, const _Tp* __first2)
00801         {
00802       return !__builtin_memcmp(__first1, __first2, sizeof(_Tp)
00803                    * (__last1 - __first1));
00804     }
00805     };
00806 
00807   template<typename _II1, typename _II2>
00808     inline bool
00809     __equal_aux(_II1 __first1, _II1 __last1, _II2 __first2)
00810     {
00811       typedef typename iterator_traits<_II1>::value_type _ValueType1;
00812       typedef typename iterator_traits<_II2>::value_type _ValueType2;
00813       const bool __simple = (__is_integer<_ValueType1>::__value
00814                          && __is_pointer<_II1>::__value
00815                          && __is_pointer<_II2>::__value
00816                  && __are_same<_ValueType1, _ValueType2>::__value);
00817 
00818       return std::__equal<__simple>::equal(__first1, __last1, __first2);
00819     }
00820 
00821 
00822   template<typename, typename>
00823     struct __lc_rai
00824     {
00825       template<typename _II1, typename _II2>
00826         static _II1
00827         __newlast1(_II1, _II1 __last1, _II2, _II2)
00828         { return __last1; }
00829 
00830       template<typename _II>
00831         static bool
00832         __cnd2(_II __first, _II __last)
00833         { return __first != __last; }
00834     };
00835 
00836   template<>
00837     struct __lc_rai<random_access_iterator_tag, random_access_iterator_tag>
00838     {
00839       template<typename _RAI1, typename _RAI2>
00840         static _RAI1
00841         __newlast1(_RAI1 __first1, _RAI1 __last1,
00842            _RAI2 __first2, _RAI2 __last2)
00843         {
00844       const typename iterator_traits<_RAI1>::difference_type
00845         __diff1 = __last1 - __first1;
00846       const typename iterator_traits<_RAI2>::difference_type
00847         __diff2 = __last2 - __first2;
00848       return __diff2 < __diff1 ? __first1 + __diff2 : __last1;
00849     }
00850 
00851       template<typename _RAI>
00852         static bool
00853         __cnd2(_RAI, _RAI)
00854         { return true; }
00855     };
00856 
00857   template<bool _BoolType>
00858     struct __lexicographical_compare
00859     {
00860       template<typename _II1, typename _II2>
00861         static bool __lc(_II1, _II1, _II2, _II2);
00862     };
00863 
00864   template<bool _BoolType>
00865     template<typename _II1, typename _II2>
00866       bool
00867       __lexicographical_compare<_BoolType>::
00868       __lc(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
00869       {
00870     typedef typename iterator_traits<_II1>::iterator_category _Category1;
00871     typedef typename iterator_traits<_II2>::iterator_category _Category2;
00872     typedef std::__lc_rai<_Category1, _Category2>   __rai_type;
00873     
00874     __last1 = __rai_type::__newlast1(__first1, __last1,
00875                      __first2, __last2);
00876     for (; __first1 != __last1 && __rai_type::__cnd2(__first2, __last2);
00877          ++__first1, ++__first2)
00878       {
00879         if (*__first1 < *__first2)
00880           return true;
00881         if (*__first2 < *__first1)
00882           return false;
00883       }
00884     return __first1 == __last1 && __first2 != __last2;
00885       }
00886 
00887   template<>
00888     struct __lexicographical_compare<true>
00889     {
00890       template<typename _Tp, typename _Up>
00891         static bool
00892         __lc(const _Tp* __first1, const _Tp* __last1,
00893          const _Up* __first2, const _Up* __last2)
00894     {
00895       const size_t __len1 = __last1 - __first1;
00896       const size_t __len2 = __last2 - __first2;
00897       const int __result = __builtin_memcmp(__first1, __first2,
00898                         std::min(__len1, __len2));
00899       return __result != 0 ? __result < 0 : __len1 < __len2;
00900     }
00901     };
00902 
00903   template<typename _II1, typename _II2>
00904     inline bool
00905     __lexicographical_compare_aux(_II1 __first1, _II1 __last1,
00906                   _II2 __first2, _II2 __last2)
00907     {
00908       typedef typename iterator_traits<_II1>::value_type _ValueType1;
00909       typedef typename iterator_traits<_II2>::value_type _ValueType2;
00910       const bool __simple =
00911     (__is_byte<_ValueType1>::__value && __is_byte<_ValueType2>::__value
00912      && !__gnu_cxx::__numeric_traits<_ValueType1>::__is_signed
00913      && !__gnu_cxx::__numeric_traits<_ValueType2>::__is_signed
00914      && __is_pointer<_II1>::__value
00915      && __is_pointer<_II2>::__value);
00916 
00917       return std::__lexicographical_compare<__simple>::__lc(__first1, __last1,
00918                                 __first2, __last2);
00919     }
00920 
00921 _GLIBCXX_END_NAMESPACE
00922 
00923 _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_P)
00924 
00925   /**
00926    *  @brief Tests a range for element-wise equality.
00927    *  @param  first1  An input iterator.
00928    *  @param  last1   An input iterator.
00929    *  @param  first2  An input iterator.
00930    *  @return   A boolean true or false.
00931    *
00932    *  This compares the elements of two ranges using @c == and returns true or
00933    *  false depending on whether all of the corresponding elements of the
00934    *  ranges are equal.
00935   */
00936   template<typename _II1, typename _II2>
00937     inline bool
00938     equal(_II1 __first1, _II1 __last1, _II2 __first2)
00939     {
00940       // concept requirements
00941       __glibcxx_function_requires(_InputIteratorConcept<_II1>)
00942       __glibcxx_function_requires(_InputIteratorConcept<_II2>)
00943       __glibcxx_function_requires(_EqualOpConcept<
00944         typename iterator_traits<_II1>::value_type,
00945         typename iterator_traits<_II2>::value_type>)
00946       __glibcxx_requires_valid_range(__first1, __last1);
00947 
00948       return std::__equal_aux(std::__niter_base<_II1>::__b(__first1),
00949                   std::__niter_base<_II1>::__b(__last1),
00950                   std::__niter_base<_II2>::__b(__first2));
00951     }
00952 
00953   /**
00954    *  @brief Tests a range for element-wise equality.
00955    *  @param  first1  An input iterator.
00956    *  @param  last1   An input iterator.
00957    *  @param  first2  An input iterator.
00958    *  @param binary_pred A binary predicate @link s20_3_1_base
00959    *                  functor@endlink.
00960    *  @return         A boolean true or false.
00961    *
00962    *  This compares the elements of two ranges using the binary_pred
00963    *  parameter, and returns true or
00964    *  false depending on whether all of the corresponding elements of the
00965    *  ranges are equal.
00966   */
00967   template<typename _IIter1, typename _IIter2, typename _BinaryPredicate>
00968     inline bool
00969     equal(_IIter1 __first1, _IIter1 __last1,
00970       _IIter2 __first2, _BinaryPredicate __binary_pred)
00971     {
00972       // concept requirements
00973       __glibcxx_function_requires(_InputIteratorConcept<_IIter1>)
00974       __glibcxx_function_requires(_InputIteratorConcept<_IIter2>)
00975       __glibcxx_requires_valid_range(__first1, __last1);
00976 
00977       for (; __first1 != __last1; ++__first1, ++__first2)
00978     if (!bool(__binary_pred(*__first1, *__first2)))
00979       return false;
00980       return true;
00981     }
00982 
00983   /**
00984    *  @brief Performs "dictionary" comparison on ranges.
00985    *  @param  first1  An input iterator.
00986    *  @param  last1   An input iterator.
00987    *  @param  first2  An input iterator.
00988    *  @param  last2   An input iterator.
00989    *  @return   A boolean true or false.
00990    *
00991    *  "Returns true if the sequence of elements defined by the range
00992    *  [first1,last1) is lexicographically less than the sequence of elements
00993    *  defined by the range [first2,last2).  Returns false otherwise."
00994    *  (Quoted from [25.3.8]/1.)  If the iterators are all character pointers,
00995    *  then this is an inline call to @c memcmp.
00996   */
00997   template<typename _II1, typename _II2>
00998     inline bool
00999     lexicographical_compare(_II1 __first1, _II1 __last1,
01000                 _II2 __first2, _II2 __last2)
01001     {
01002       // concept requirements
01003       typedef typename iterator_traits<_II1>::value_type _ValueType1;
01004       typedef typename iterator_traits<_II2>::value_type _ValueType2;
01005       __glibcxx_function_requires(_InputIteratorConcept<_II1>)
01006       __glibcxx_function_requires(_InputIteratorConcept<_II2>)
01007       __glibcxx_function_requires(_LessThanOpConcept<_ValueType1, _ValueType2>)
01008       __glibcxx_function_requires(_LessThanOpConcept<_ValueType2, _ValueType1>)
01009       __glibcxx_requires_valid_range(__first1, __last1);
01010       __glibcxx_requires_valid_range(__first2, __last2);
01011 
01012       return std::__lexicographical_compare_aux
01013     (std::__niter_base<_II1>::__b(__first1),
01014      std::__niter_base<_II1>::__b(__last1),
01015      std::__niter_base<_II2>::__b(__first2),
01016      std::__niter_base<_II2>::__b(__last2));
01017     }
01018 
01019   /**
01020    *  @brief Performs "dictionary" comparison on ranges.
01021    *  @param  first1  An input iterator.
01022    *  @param  last1   An input iterator.
01023    *  @param  first2  An input iterator.
01024    *  @param  last2   An input iterator.
01025    *  @param  comp  A @link s20_3_3_comparisons comparison functor@endlink.
01026    *  @return   A boolean true or false.
01027    *
01028    *  The same as the four-parameter @c lexicographical_compare, but uses the
01029    *  comp parameter instead of @c <.
01030   */
01031   template<typename _II1, typename _II2, typename _Compare>
01032     bool
01033     lexicographical_compare(_II1 __first1, _II1 __last1,
01034                 _II2 __first2, _II2 __last2, _Compare __comp)
01035     {
01036       typedef typename iterator_traits<_II1>::iterator_category _Category1;
01037       typedef typename iterator_traits<_II2>::iterator_category _Category2;
01038       typedef std::__lc_rai<_Category1, _Category2>     __rai_type;
01039 
01040       // concept requirements
01041       __glibcxx_function_requires(_InputIteratorConcept<_II1>)
01042       __glibcxx_function_requires(_InputIteratorConcept<_II2>)
01043       __glibcxx_requires_valid_range(__first1, __last1);
01044       __glibcxx_requires_valid_range(__first2, __last2);
01045 
01046       __last1 = __rai_type::__newlast1(__first1, __last1, __first2, __last2);
01047       for (; __first1 != __last1 && __rai_type::__cnd2(__first2, __last2);
01048        ++__first1, ++__first2)
01049     {
01050       if (__comp(*__first1, *__first2))
01051         return true;
01052       if (__comp(*__first2, *__first1))
01053         return false;
01054     }
01055       return __first1 == __last1 && __first2 != __last2;
01056     }
01057 
01058   /**
01059    *  @brief Finds the places in ranges which don't match.
01060    *  @param  first1  An input iterator.
01061    *  @param  last1   An input iterator.
01062    *  @param  first2  An input iterator.
01063    *  @return   A pair of iterators pointing to the first mismatch.
01064    *
01065    *  This compares the elements of two ranges using @c == and returns a pair
01066    *  of iterators.  The first iterator points into the first range, the
01067    *  second iterator points into the second range, and the elements pointed
01068    *  to by the iterators are not equal.
01069   */
01070   template<typename _InputIterator1, typename _InputIterator2>
01071     pair<_InputIterator1, _InputIterator2>
01072     mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
01073          _InputIterator2 __first2)
01074     {
01075       // concept requirements
01076       __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
01077       __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
01078       __glibcxx_function_requires(_EqualOpConcept<
01079         typename iterator_traits<_InputIterator1>::value_type,
01080         typename iterator_traits<_InputIterator2>::value_type>)
01081       __glibcxx_requires_valid_range(__first1, __last1);
01082 
01083       while (__first1 != __last1 && *__first1 == *__first2)
01084         {
01085       ++__first1;
01086       ++__first2;
01087         }
01088       return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
01089     }
01090 
01091   /**
01092    *  @brief Finds the places in ranges which don't match.
01093    *  @param  first1  An input iterator.
01094    *  @param  last1   An input iterator.
01095    *  @param  first2  An input iterator.
01096    *  @param binary_pred A binary predicate @link s20_3_1_base
01097    *         functor@endlink.
01098    *  @return   A pair of iterators pointing to the first mismatch.
01099    *
01100    *  This compares the elements of two ranges using the binary_pred
01101    *  parameter, and returns a pair
01102    *  of iterators.  The first iterator points into the first range, the
01103    *  second iterator points into the second range, and the elements pointed
01104    *  to by the iterators are not equal.
01105   */
01106   template<typename _InputIterator1, typename _InputIterator2,
01107        typename _BinaryPredicate>
01108     pair<_InputIterator1, _InputIterator2>
01109     mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
01110          _InputIterator2 __first2, _BinaryPredicate __binary_pred)
01111     {
01112       // concept requirements
01113       __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
01114       __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
01115       __glibcxx_requires_valid_range(__first1, __last1);
01116 
01117       while (__first1 != __last1 && bool(__binary_pred(*__first1, *__first2)))
01118         {
01119       ++__first1;
01120       ++__first2;
01121         }
01122       return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
01123     }
01124 
01125 _GLIBCXX_END_NESTED_NAMESPACE
01126 
01127 // NB: This file is included within many other C++ includes, as a way
01128 // of getting the base algorithms. So, make sure that parallel bits
01129 // come in too if requested. 
01130 #ifdef _GLIBCXX_PARALLEL
01131 # include <parallel/algobase.h>
01132 #endif
01133 
01134 #endif

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