libstdc++-v3/include/parallel/algo.h

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2007-2016 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 terms
   7 // of the GNU General Public License as published by the Free Software
   8 // Foundation; either version 3, or (at your option) any later
   9 // version.
  10
  11 // This library is distributed in the hope that it will be useful, but
  12 // WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 // 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 /** @file parallel/algo.h
  26  *  @brief Parallel STL function calls corresponding to the stl_algo.h header.
  27  *
  28  *  The functions defined here mainly do case switches and
  29  *  call the actual parallelized versions in other files.
  30  *  Inlining policy: Functions that basically only contain one function call,
  31  *  are declared inline.
  32  *  This file is a GNU parallel extension to the Standard C++ Library.
  33  */
  34
  35 // Written by Johannes Singler and Felix Putze.
  36
  37 #ifndef _GLIBCXX_PARALLEL_ALGO_H
  38 #define _GLIBCXX_PARALLEL_ALGO_H 1
  39
  40 #include <parallel/algorithmfwd.h>
  41 #include <bits/stl_algobase.h>
  42 #include <bits/stl_algo.h>
  43 #include <parallel/iterator.h>
  44 #include <parallel/base.h>
  45 #include <parallel/sort.h>
  46 #include <parallel/workstealing.h>
  47 #include <parallel/par_loop.h>
  48 #include <parallel/omp_loop.h>
  49 #include <parallel/omp_loop_static.h>
  50 #include <parallel/for_each_selectors.h>
  51 #include <parallel/for_each.h>
  52 #include <parallel/find.h>
  53 #include <parallel/find_selectors.h>
  54 #include <parallel/search.h>
  55 #include <parallel/random_shuffle.h>
  56 #include <parallel/partition.h>
  57 #include <parallel/merge.h>
  58 #include <parallel/unique_copy.h>
  59 #include <parallel/set_operations.h>
  60
  61 namespace std _GLIBCXX_VISIBILITY(default)
  62 {
  63 namespace __parallel
  64 {
  65   // Sequential fallback
  66   template<typename _IIter, typename _Function>
  67     inline _Function
  68     for_each(_IIter __begin, _IIter __end, _Function __f,
  69              __gnu_parallel::sequential_tag)
  70     { return _GLIBCXX_STD_A::for_each(__begin, __end, __f); }
  71
  72   // Sequential fallback for input iterator case
  73   template<typename _IIter, typename _Function, typename _IteratorTag>
  74     inline _Function
  75     __for_each_switch(_IIter __begin, _IIter __end, _Function __f,
  76                       _IteratorTag)
  77     { return for_each(__begin, __end, __f, __gnu_parallel::sequential_tag()); }
  78
  79   // Parallel algorithm for random access iterators
  80   template<typename _RAIter, typename _Function>
  81     _Function
  82     __for_each_switch(_RAIter __begin, _RAIter __end,
  83                       _Function __f, random_access_iterator_tag,
  84                       __gnu_parallel::_Parallelism __parallelism_tag)
  85     {
  86       if (_GLIBCXX_PARALLEL_CONDITION(
  87             static_cast<__gnu_parallel::_SequenceIndex>(__end - __begin)
  88             >= __gnu_parallel::_Settings::get().for_each_minimal_n
  89             && __gnu_parallel::__is_parallel(__parallelism_tag)))
  90         {
  91           bool __dummy;
  92           __gnu_parallel::__for_each_selector<_RAIter> __functionality;
  93
  94           return __gnu_parallel::
  95             __for_each_template_random_access(
  96               __begin, __end, __f, __functionality,
  97               __gnu_parallel::_DummyReduct(), true, __dummy, -1,
  98               __parallelism_tag);
  99         }
 100       else
 101         return for_each(__begin, __end, __f, __gnu_parallel::sequential_tag());
 102     }
 103
 104   // Public interface
 105   template<typename _Iterator, typename _Function>
 106     inline _Function
 107     for_each(_Iterator __begin, _Iterator __end, _Function __f,
 108              __gnu_parallel::_Parallelism __parallelism_tag)
 109     {
 110       return __for_each_switch(__begin, __end, __f,
 111                                std::__iterator_category(__begin),
 112                                __parallelism_tag);
 113     }
 114
 115   template<typename _Iterator, typename _Function>
 116     inline _Function
 117     for_each(_Iterator __begin, _Iterator __end, _Function __f)
 118     {
 119       return __for_each_switch(__begin, __end, __f,
 120                                std::__iterator_category(__begin));
 121     }
 122
 123   // Sequential fallback
 124   template<typename _IIter, typename _Tp>
 125     inline _IIter
 126     find(_IIter __begin, _IIter __end, const _Tp& __val,
 127          __gnu_parallel::sequential_tag)
 128     { return _GLIBCXX_STD_A::find(__begin, __end, __val); }
 129
 130   // Sequential fallback for input iterator case
 131   template<typename _IIter, typename _Tp, typename _IteratorTag>
 132     inline _IIter
 133     __find_switch(_IIter __begin, _IIter __end, const _Tp& __val,
 134                 _IteratorTag)
 135     { return _GLIBCXX_STD_A::find(__begin, __end, __val); }
 136
 137   // Parallel find for random access iterators
 138   template<typename _RAIter, typename _Tp>
 139     _RAIter
 140     __find_switch(_RAIter __begin, _RAIter __end,
 141                 const _Tp& __val, random_access_iterator_tag)
 142     {
 143       typedef iterator_traits<_RAIter> _TraitsType;
 144       typedef typename _TraitsType::value_type _ValueType;
 145
 146       if (_GLIBCXX_PARALLEL_CONDITION(true))
 147         {
 148           __gnu_parallel::__binder2nd<__gnu_parallel::_EqualTo<_ValueType,
 149                                                                const _Tp&>,
 150                                       _ValueType, const _Tp&, bool>
 151             __comp(__gnu_parallel::_EqualTo<_ValueType, const _Tp&>(), __val);
 152           return __gnu_parallel::__find_template(
 153                    __begin, __end, __begin, __comp,
 154                    __gnu_parallel::__find_if_selector()).first;
 155         }
 156       else
 157         return _GLIBCXX_STD_A::find(__begin, __end, __val);
 158     }
 159
 160   // Public interface
 161   template<typename _IIter, typename _Tp>
 162     inline _IIter
 163     find(_IIter __begin, _IIter __end, const _Tp& __val)
 164     {
 165       return __find_switch(__begin, __end, __val,
 166                            std::__iterator_category(__begin));
 167     }
 168
 169   // Sequential fallback
 170   template<typename _IIter, typename _Predicate>
 171     inline _IIter
 172     find_if(_IIter __begin, _IIter __end, _Predicate __pred,
 173             __gnu_parallel::sequential_tag)
 174     { return _GLIBCXX_STD_A::find_if(__begin, __end, __pred); }
 175
 176   // Sequential fallback for input iterator case
 177   template<typename _IIter, typename _Predicate, typename _IteratorTag>
 178     inline _IIter
 179     __find_if_switch(_IIter __begin, _IIter __end, _Predicate __pred,
 180                    _IteratorTag)
 181     { return _GLIBCXX_STD_A::find_if(__begin, __end, __pred); }
 182
 183   // Parallel find_if for random access iterators
 184   template<typename _RAIter, typename _Predicate>
 185     _RAIter
 186     __find_if_switch(_RAIter __begin, _RAIter __end,
 187                    _Predicate __pred, random_access_iterator_tag)
 188     {
 189       if (_GLIBCXX_PARALLEL_CONDITION(true))
 190         return __gnu_parallel::__find_template(__begin, __end, __begin, __pred,
 191                                              __gnu_parallel::
 192                                              __find_if_selector()).first;
 193       else
 194         return _GLIBCXX_STD_A::find_if(__begin, __end, __pred);
 195     }
 196
 197   // Public interface
 198   template<typename _IIter, typename _Predicate>
 199     inline _IIter
 200     find_if(_IIter __begin, _IIter __end, _Predicate __pred)
 201     {
 202       return __find_if_switch(__begin, __end, __pred,
 203                               std::__iterator_category(__begin));
 204     }
 205
 206   // Sequential fallback
 207   template<typename _IIter, typename _FIterator>
 208     inline _IIter
 209     find_first_of(_IIter __begin1, _IIter __end1,
 210                   _FIterator __begin2, _FIterator __end2,
 211                   __gnu_parallel::sequential_tag)
 212     {
 213       return _GLIBCXX_STD_A::find_first_of(__begin1, __end1, __begin2, __end2);
 214     }
 215
 216   // Sequential fallback
 217   template<typename _IIter, typename _FIterator,
 218            typename _BinaryPredicate>
 219     inline _IIter
 220     find_first_of(_IIter __begin1, _IIter __end1,
 221                   _FIterator __begin2, _FIterator __end2,
 222                   _BinaryPredicate __comp, __gnu_parallel::sequential_tag)
 223   { return _GLIBCXX_STD_A::find_first_of(
 224              __begin1, __end1, __begin2, __end2, __comp); }
 225
 226   // Sequential fallback for input iterator type
 227   template<typename _IIter, typename _FIterator,
 228            typename _IteratorTag1, typename _IteratorTag2>
 229     inline _IIter
 230     __find_first_of_switch(_IIter __begin1, _IIter __end1,
 231                            _FIterator __begin2, _FIterator __end2,
 232                            _IteratorTag1, _IteratorTag2)
 233     { return find_first_of(__begin1, __end1, __begin2, __end2,
 234                            __gnu_parallel::sequential_tag()); }
 235
 236   // Parallel algorithm for random access iterators
 237   template<typename _RAIter, typename _FIterator,
 238            typename _BinaryPredicate, typename _IteratorTag>
 239     inline _RAIter
 240     __find_first_of_switch(_RAIter __begin1,
 241                            _RAIter __end1,
 242                            _FIterator __begin2, _FIterator __end2,
 243                            _BinaryPredicate __comp, random_access_iterator_tag,
 244                            _IteratorTag)
 245     {
 246       return __gnu_parallel::
 247         __find_template(__begin1, __end1, __begin1, __comp,
 248                       __gnu_parallel::__find_first_of_selector
 249                       <_FIterator>(__begin2, __end2)).first;
 250     }
 251
 252   // Sequential fallback for input iterator type
 253   template<typename _IIter, typename _FIterator,
 254            typename _BinaryPredicate, typename _IteratorTag1,
 255            typename _IteratorTag2>
 256     inline _IIter
 257     __find_first_of_switch(_IIter __begin1, _IIter __end1,
 258                            _FIterator __begin2, _FIterator __end2,
 259                            _BinaryPredicate __comp, _IteratorTag1, _IteratorTag2)
 260     { return find_first_of(__begin1, __end1, __begin2, __end2, __comp,
 261                            __gnu_parallel::sequential_tag()); }
 262
 263   // Public interface
 264   template<typename _IIter, typename _FIterator,
 265            typename _BinaryPredicate>
 266     inline _IIter
 267     find_first_of(_IIter __begin1, _IIter __end1,
 268                   _FIterator __begin2, _FIterator __end2,
 269                   _BinaryPredicate __comp)
 270     {
 271       return __find_first_of_switch(__begin1, __end1, __begin2, __end2, __comp,
 272                                     std::__iterator_category(__begin1),
 273                                     std::__iterator_category(__begin2));
 274     }
 275
 276   // Public interface, insert default comparator
 277   template<typename _IIter, typename _FIterator>
 278     inline _IIter
 279     find_first_of(_IIter __begin1, _IIter __end1,
 280                   _FIterator __begin2, _FIterator __end2)
 281     {
 282       typedef typename std::iterator_traits<_IIter>::value_type _IValueType;
 283       typedef typename std::iterator_traits<_FIterator>::value_type _FValueType;
 284
 285       return __gnu_parallel::find_first_of(__begin1, __end1, __begin2, __end2,
 286                          __gnu_parallel::_EqualTo<_IValueType, _FValueType>());
 287     }
 288
 289   // Sequential fallback
 290   template<typename _IIter, typename _OutputIterator>
 291     inline _OutputIterator
 292     unique_copy(_IIter __begin1, _IIter __end1, _OutputIterator __out,
 293                 __gnu_parallel::sequential_tag)
 294     { return _GLIBCXX_STD_A::unique_copy(__begin1, __end1, __out); }
 295
 296   // Sequential fallback
 297   template<typename _IIter, typename _OutputIterator,
 298            typename _Predicate>
 299     inline _OutputIterator
 300     unique_copy(_IIter __begin1, _IIter __end1, _OutputIterator __out,
 301                 _Predicate __pred, __gnu_parallel::sequential_tag)
 302     { return _GLIBCXX_STD_A::unique_copy(__begin1, __end1, __out, __pred); }
 303
 304   // Sequential fallback for input iterator case
 305   template<typename _IIter, typename _OutputIterator,
 306            typename _Predicate, typename _IteratorTag1, typename _IteratorTag2>
 307     inline _OutputIterator
 308     __unique_copy_switch(_IIter __begin, _IIter __last,
 309                        _OutputIterator __out, _Predicate __pred,
 310                        _IteratorTag1, _IteratorTag2)
 311     { return _GLIBCXX_STD_A::unique_copy(__begin, __last, __out, __pred); }
 312
 313   // Parallel unique_copy for random access iterators
 314   template<typename _RAIter, typename RandomAccessOutputIterator,
 315            typename _Predicate>
 316     RandomAccessOutputIterator
 317     __unique_copy_switch(_RAIter __begin, _RAIter __last,
 318                          RandomAccessOutputIterator __out, _Predicate __pred,
 319                          random_access_iterator_tag, random_access_iterator_tag)
 320     {
 321       if (_GLIBCXX_PARALLEL_CONDITION(
 322             static_cast<__gnu_parallel::_SequenceIndex>(__last - __begin)
 323             > __gnu_parallel::_Settings::get().unique_copy_minimal_n))
 324         return __gnu_parallel::__parallel_unique_copy(
 325                  __begin, __last, __out, __pred);
 326       else
 327         return _GLIBCXX_STD_A::unique_copy(__begin, __last, __out, __pred);
 328     }
 329
 330   // Public interface
 331   template<typename _IIter, typename _OutputIterator>
 332     inline _OutputIterator
 333     unique_copy(_IIter __begin1, _IIter __end1, _OutputIterator __out)
 334     {
 335       typedef typename std::iterator_traits<_IIter>::value_type _ValueType;
 336
 337       return __unique_copy_switch(
 338                __begin1, __end1, __out, equal_to<_ValueType>(),
 339                std::__iterator_category(__begin1),
 340                std::__iterator_category(__out));
 341     }
 342
 343   // Public interface
 344   template<typename _IIter, typename _OutputIterator, typename _Predicate>
 345     inline _OutputIterator
 346     unique_copy(_IIter __begin1, _IIter __end1, _OutputIterator __out,
 347                 _Predicate __pred)
 348     {
 349       return __unique_copy_switch(
 350                __begin1, __end1, __out, __pred,
 351                std::__iterator_category(__begin1),
 352                std::__iterator_category(__out));
 353     }
 354
 355   // Sequential fallback
 356   template<typename _IIter1, typename _IIter2,
 357            typename _OutputIterator>
 358     inline _OutputIterator
 359     set_union(_IIter1 __begin1, _IIter1 __end1,
 360               _IIter2 __begin2, _IIter2 __end2,
 361               _OutputIterator __out, __gnu_parallel::sequential_tag)
 362     { return _GLIBCXX_STD_A::set_union(
 363                __begin1, __end1, __begin2, __end2, __out); }
 364
 365   // Sequential fallback
 366   template<typename _IIter1, typename _IIter2,
 367            typename _OutputIterator, typename _Predicate>
 368     inline _OutputIterator
 369     set_union(_IIter1 __begin1, _IIter1 __end1,
 370               _IIter2 __begin2, _IIter2 __end2,
 371               _OutputIterator __out, _Predicate __pred,
 372               __gnu_parallel::sequential_tag)
 373     { return _GLIBCXX_STD_A::set_union(__begin1, __end1,
 374                                        __begin2, __end2, __out, __pred); }
 375
 376   // Sequential fallback for input iterator case
 377   template<typename _IIter1, typename _IIter2, typename _Predicate,
 378            typename _OutputIterator, typename _IteratorTag1,
 379            typename _IteratorTag2, typename _IteratorTag3>
 380     inline _OutputIterator
 381     __set_union_switch(
 382       _IIter1 __begin1, _IIter1 __end1, _IIter2 __begin2, _IIter2 __end2,
 383       _OutputIterator __result, _Predicate __pred,
 384       _IteratorTag1, _IteratorTag2, _IteratorTag3)
 385     { return _GLIBCXX_STD_A::set_union(__begin1, __end1,
 386                                        __begin2, __end2, __result, __pred); }
 387
 388   // Parallel set_union for random access iterators
 389   template<typename _RAIter1, typename _RAIter2,
 390            typename _Output_RAIter, typename _Predicate>
 391     _Output_RAIter
 392     __set_union_switch(_RAIter1 __begin1, _RAIter1 __end1,
 393                        _RAIter2 __begin2, _RAIter2 __end2,
 394                        _Output_RAIter __result, _Predicate __pred,
 395                        random_access_iterator_tag, random_access_iterator_tag,
 396                        random_access_iterator_tag)
 397     {
 398       if (_GLIBCXX_PARALLEL_CONDITION(
 399             static_cast<__gnu_parallel::_SequenceIndex>(__end1 - __begin1)
 400             >= __gnu_parallel::_Settings::get().set_union_minimal_n
 401             || static_cast<__gnu_parallel::_SequenceIndex>(__end2 - __begin2)
 402             >= __gnu_parallel::_Settings::get().set_union_minimal_n))
 403         return __gnu_parallel::__parallel_set_union(
 404                  __begin1, __end1, __begin2, __end2, __result, __pred);
 405       else
 406         return _GLIBCXX_STD_A::set_union(__begin1, __end1,
 407                                          __begin2, __end2, __result, __pred);
 408     }
 409
 410   // Public interface
 411   template<typename _IIter1, typename _IIter2,
 412            typename _OutputIterator>
 413     inline _OutputIterator
 414     set_union(_IIter1 __begin1, _IIter1 __end1,
 415               _IIter2 __begin2, _IIter2 __end2, _OutputIterator __out)
 416     {
 417       typedef typename std::iterator_traits<_IIter1>::value_type _ValueType1;
 418       typedef typename std::iterator_traits<_IIter2>::value_type _ValueType2;
 419
 420       return __set_union_switch(
 421                __begin1, __end1, __begin2, __end2, __out,
 422                __gnu_parallel::_Less<_ValueType1, _ValueType2>(),
 423                std::__iterator_category(__begin1),
 424                std::__iterator_category(__begin2),
 425                std::__iterator_category(__out));
 426     }
 427
 428   // Public interface
 429   template<typename _IIter1, typename _IIter2,
 430            typename _OutputIterator, typename _Predicate>
 431     inline _OutputIterator
 432     set_union(_IIter1 __begin1, _IIter1 __end1,
 433               _IIter2 __begin2, _IIter2 __end2,
 434               _OutputIterator __out, _Predicate __pred)
 435     {
 436       return __set_union_switch(
 437                __begin1, __end1, __begin2, __end2, __out, __pred,
 438                std::__iterator_category(__begin1),
 439                std::__iterator_category(__begin2),
 440                std::__iterator_category(__out));
 441     }
 442
 443   // Sequential fallback.
 444   template<typename _IIter1, typename _IIter2,
 445            typename _OutputIterator>
 446     inline _OutputIterator
 447     set_intersection(_IIter1 __begin1, _IIter1 __end1,
 448                      _IIter2 __begin2, _IIter2 __end2,
 449                      _OutputIterator __out, __gnu_parallel::sequential_tag)
 450     { return _GLIBCXX_STD_A::set_intersection(__begin1, __end1,
 451                                               __begin2, __end2, __out); }
 452
 453   // Sequential fallback.
 454   template<typename _IIter1, typename _IIter2,
 455            typename _OutputIterator, typename _Predicate>
 456     inline _OutputIterator
 457     set_intersection(_IIter1 __begin1, _IIter1 __end1,
 458                      _IIter2 __begin2, _IIter2 __end2,
 459                      _OutputIterator __out, _Predicate __pred,
 460                      __gnu_parallel::sequential_tag)
 461     { return _GLIBCXX_STD_A::set_intersection(
 462                __begin1, __end1, __begin2, __end2, __out, __pred); }
 463
 464   // Sequential fallback for input iterator case
 465   template<typename _IIter1, typename _IIter2,
 466            typename _Predicate, typename _OutputIterator,
 467            typename _IteratorTag1, typename _IteratorTag2,
 468            typename _IteratorTag3>
 469     inline _OutputIterator
 470     __set_intersection_switch(_IIter1 __begin1, _IIter1 __end1,
 471                               _IIter2 __begin2, _IIter2 __end2,
 472                               _OutputIterator __result, _Predicate __pred,
 473                               _IteratorTag1, _IteratorTag2, _IteratorTag3)
 474     { return _GLIBCXX_STD_A::set_intersection(__begin1, __end1, __begin2,
 475                                               __end2, __result, __pred); }
 476
 477   // Parallel set_intersection for random access iterators
 478   template<typename _RAIter1, typename _RAIter2,
 479            typename _Output_RAIter, typename _Predicate>
 480     _Output_RAIter
 481     __set_intersection_switch(_RAIter1 __begin1,
 482                               _RAIter1 __end1,
 483                               _RAIter2 __begin2,
 484                               _RAIter2 __end2,
 485                               _Output_RAIter __result,
 486                               _Predicate __pred,
 487                               random_access_iterator_tag,
 488                               random_access_iterator_tag,
 489                               random_access_iterator_tag)
 490     {
 491       if (_GLIBCXX_PARALLEL_CONDITION(
 492             static_cast<__gnu_parallel::_SequenceIndex>(__end1 - __begin1)
 493             >= __gnu_parallel::_Settings::get().set_union_minimal_n
 494             || static_cast<__gnu_parallel::_SequenceIndex>(__end2 - __begin2)
 495             >= __gnu_parallel::_Settings::get().set_union_minimal_n))
 496         return __gnu_parallel::__parallel_set_intersection(
 497                  __begin1, __end1, __begin2, __end2, __result, __pred);
 498       else
 499         return _GLIBCXX_STD_A::set_intersection(
 500                  __begin1, __end1, __begin2, __end2, __result, __pred);
 501     }
 502
 503   // Public interface
 504   template<typename _IIter1, typename _IIter2,
 505            typename _OutputIterator>
 506     inline _OutputIterator
 507     set_intersection(_IIter1 __begin1, _IIter1 __end1,
 508                      _IIter2 __begin2, _IIter2 __end2,
 509                      _OutputIterator __out)
 510     {
 511       typedef typename std::iterator_traits<_IIter1>::value_type _ValueType1;
 512       typedef typename std::iterator_traits<_IIter2>::value_type _ValueType2;
 513
 514       return __set_intersection_switch(
 515                __begin1, __end1, __begin2, __end2, __out,
 516                __gnu_parallel::_Less<_ValueType1, _ValueType2>(),
 517                std::__iterator_category(__begin1),
 518                std::__iterator_category(__begin2),
 519                std::__iterator_category(__out));
 520     }
 521
 522   template<typename _IIter1, typename _IIter2,
 523            typename _OutputIterator, typename _Predicate>
 524     inline _OutputIterator
 525     set_intersection(_IIter1 __begin1, _IIter1 __end1,
 526                      _IIter2 __begin2, _IIter2 __end2,
 527                      _OutputIterator __out, _Predicate __pred)
 528     {
 529       return __set_intersection_switch(
 530                __begin1, __end1, __begin2, __end2, __out, __pred,
 531                std::__iterator_category(__begin1),
 532                std::__iterator_category(__begin2),
 533                std::__iterator_category(__out));
 534     }
 535
 536   // Sequential fallback
 537   template<typename _IIter1, typename _IIter2,
 538            typename _OutputIterator>
 539     inline _OutputIterator
 540     set_symmetric_difference(_IIter1 __begin1, _IIter1 __end1,
 541                              _IIter2 __begin2, _IIter2 __end2,
 542                              _OutputIterator __out,
 543                              __gnu_parallel::sequential_tag)
 544     { return _GLIBCXX_STD_A::set_symmetric_difference(
 545                __begin1, __end1, __begin2, __end2, __out); }
 546
 547   // Sequential fallback
 548   template<typename _IIter1, typename _IIter2,
 549            typename _OutputIterator, typename _Predicate>
 550     inline _OutputIterator
 551     set_symmetric_difference(_IIter1 __begin1, _IIter1 __end1,
 552                              _IIter2 __begin2, _IIter2 __end2,
 553                              _OutputIterator __out, _Predicate __pred,
 554                              __gnu_parallel::sequential_tag)
 555     { return _GLIBCXX_STD_A::set_symmetric_difference(
 556                __begin1, __end1, __begin2, __end2, __out, __pred); }
 557
 558   // Sequential fallback for input iterator case
 559   template<typename _IIter1, typename _IIter2,
 560            typename _Predicate, typename _OutputIterator,
 561            typename _IteratorTag1, typename _IteratorTag2,
 562            typename _IteratorTag3>
 563     inline _OutputIterator
 564     __set_symmetric_difference_switch(
 565         _IIter1 __begin1, _IIter1 __end1, _IIter2 __begin2, _IIter2 __end2,
 566         _OutputIterator __result, _Predicate __pred,
 567         _IteratorTag1, _IteratorTag2, _IteratorTag3)
 568     { return _GLIBCXX_STD_A::set_symmetric_difference(
 569                __begin1, __end1, __begin2, __end2, __result, __pred); }
 570
 571   // Parallel set_symmetric_difference for random access iterators
 572   template<typename _RAIter1, typename _RAIter2,
 573            typename _Output_RAIter, typename _Predicate>
 574     _Output_RAIter
 575     __set_symmetric_difference_switch(_RAIter1 __begin1,
 576                                       _RAIter1 __end1,
 577                                       _RAIter2 __begin2,
 578                                       _RAIter2 __end2,
 579                                       _Output_RAIter __result,
 580                                       _Predicate __pred,
 581                                       random_access_iterator_tag,
 582                                       random_access_iterator_tag,
 583                                       random_access_iterator_tag)
 584     {
 585       if (_GLIBCXX_PARALLEL_CONDITION(
 586       static_cast<__gnu_parallel::_SequenceIndex>(__end1 - __begin1)
 587       >= __gnu_parallel::_Settings::get().set_symmetric_difference_minimal_n
 588       || static_cast<__gnu_parallel::_SequenceIndex>(__end2 - __begin2)
 589       >= __gnu_parallel::_Settings::get().set_symmetric_difference_minimal_n))
 590   return __gnu_parallel::__parallel_set_symmetric_difference(
 591            __begin1, __end1, __begin2, __end2, __result, __pred);
 592       else
 593         return _GLIBCXX_STD_A::set_symmetric_difference(
 594                  __begin1, __end1, __begin2, __end2, __result, __pred);
 595     }
 596
 597   // Public interface.
 598   template<typename _IIter1, typename _IIter2,
 599            typename _OutputIterator>
 600     inline _OutputIterator
 601     set_symmetric_difference(_IIter1 __begin1, _IIter1 __end1,
 602                              _IIter2 __begin2, _IIter2 __end2,
 603                              _OutputIterator __out)
 604     {
 605       typedef typename std::iterator_traits<_IIter1>::value_type _ValueType1;
 606       typedef typename std::iterator_traits<_IIter2>::value_type _ValueType2;
 607
 608       return __set_symmetric_difference_switch(
 609                __begin1, __end1, __begin2, __end2, __out,
 610                __gnu_parallel::_Less<_ValueType1, _ValueType2>(),
 611                std::__iterator_category(__begin1),
 612                std::__iterator_category(__begin2),
 613                std::__iterator_category(__out));
 614     }
 615
 616   // Public interface.
 617   template<typename _IIter1, typename _IIter2,
 618            typename _OutputIterator, typename _Predicate>
 619     inline _OutputIterator
 620     set_symmetric_difference(_IIter1 __begin1, _IIter1 __end1,
 621                              _IIter2 __begin2, _IIter2 __end2,
 622                              _OutputIterator __out, _Predicate __pred)
 623     {
 624       return __set_symmetric_difference_switch(
 625                __begin1, __end1, __begin2, __end2, __out, __pred,
 626                std::__iterator_category(__begin1),
 627                std::__iterator_category(__begin2),
 628                std::__iterator_category(__out));
 629     }
 630
 631   // Sequential fallback.
 632   template<typename _IIter1, typename _IIter2,
 633            typename _OutputIterator>
 634     inline _OutputIterator
 635     set_difference(_IIter1 __begin1, _IIter1 __end1,
 636                    _IIter2 __begin2, _IIter2 __end2,
 637                    _OutputIterator __out, __gnu_parallel::sequential_tag)
 638     { return _GLIBCXX_STD_A::set_difference(
 639                __begin1,__end1, __begin2, __end2, __out); }
 640
 641   // Sequential fallback.
 642   template<typename _IIter1, typename _IIter2,
 643            typename _OutputIterator, typename _Predicate>
 644     inline _OutputIterator
 645     set_difference(_IIter1 __begin1, _IIter1 __end1,
 646                    _IIter2 __begin2, _IIter2 __end2,
 647                    _OutputIterator __out, _Predicate __pred,
 648                    __gnu_parallel::sequential_tag)
 649     { return _GLIBCXX_STD_A::set_difference(__begin1, __end1,
 650                                             __begin2, __end2, __out, __pred); }
 651
 652   // Sequential fallback for input iterator case.
 653   template<typename _IIter1, typename _IIter2, typename _Predicate,
 654            typename _OutputIterator, typename _IteratorTag1,
 655            typename _IteratorTag2, typename _IteratorTag3>
 656     inline _OutputIterator
 657     __set_difference_switch(_IIter1 __begin1, _IIter1 __end1,
 658                             _IIter2 __begin2, _IIter2 __end2,
 659                             _OutputIterator __result, _Predicate __pred,
 660                             _IteratorTag1, _IteratorTag2, _IteratorTag3)
 661     { return _GLIBCXX_STD_A::set_difference(
 662                __begin1, __end1, __begin2, __end2, __result, __pred); }
 663
 664   // Parallel set_difference for random access iterators
 665   template<typename _RAIter1, typename _RAIter2,
 666            typename _Output_RAIter, typename _Predicate>
 667     _Output_RAIter
 668     __set_difference_switch(_RAIter1 __begin1,
 669                             _RAIter1 __end1,
 670                             _RAIter2 __begin2,
 671                             _RAIter2 __end2,
 672                             _Output_RAIter __result, _Predicate __pred,
 673                             random_access_iterator_tag,
 674                             random_access_iterator_tag,
 675                             random_access_iterator_tag)
 676     {
 677       if (_GLIBCXX_PARALLEL_CONDITION(
 678             static_cast<__gnu_parallel::_SequenceIndex>(__end1 - __begin1)
 679             >= __gnu_parallel::_Settings::get().set_difference_minimal_n
 680             || static_cast<__gnu_parallel::_SequenceIndex>(__end2 - __begin2)
 681             >= __gnu_parallel::_Settings::get().set_difference_minimal_n))
 682         return __gnu_parallel::__parallel_set_difference(
 683                  __begin1, __end1, __begin2, __end2, __result, __pred);
 684       else
 685         return _GLIBCXX_STD_A::set_difference(
 686                  __begin1, __end1, __begin2, __end2, __result, __pred);
 687     }
 688
 689   // Public interface
 690   template<typename _IIter1, typename _IIter2,
 691            typename _OutputIterator>
 692     inline _OutputIterator
 693     set_difference(_IIter1 __begin1, _IIter1 __end1,
 694                    _IIter2 __begin2, _IIter2 __end2,
 695                    _OutputIterator __out)
 696     {
 697       typedef typename std::iterator_traits<_IIter1>::value_type _ValueType1;
 698       typedef typename std::iterator_traits<_IIter2>::value_type _ValueType2;
 699
 700       return __set_difference_switch(
 701                __begin1, __end1, __begin2, __end2, __out,
 702                __gnu_parallel::_Less<_ValueType1, _ValueType2>(),
 703                std::__iterator_category(__begin1),
 704                std::__iterator_category(__begin2),
 705                std::__iterator_category(__out));
 706     }
 707
 708   // Public interface
 709   template<typename _IIter1, typename _IIter2,
 710            typename _OutputIterator, typename _Predicate>
 711     inline _OutputIterator
 712     set_difference(_IIter1 __begin1, _IIter1 __end1,
 713                    _IIter2 __begin2, _IIter2 __end2,
 714                    _OutputIterator __out, _Predicate __pred)
 715     {
 716       return __set_difference_switch(
 717                __begin1, __end1, __begin2, __end2, __out, __pred,
 718                std::__iterator_category(__begin1),
 719                std::__iterator_category(__begin2),
 720                std::__iterator_category(__out));
 721     }
 722
 723   // Sequential fallback
 724   template<typename _FIterator>
 725     inline _FIterator
 726     adjacent_find(_FIterator __begin, _FIterator __end,
 727                   __gnu_parallel::sequential_tag)
 728     { return _GLIBCXX_STD_A::adjacent_find(__begin, __end); }
 729
 730   // Sequential fallback
 731   template<typename _FIterator, typename _BinaryPredicate>
 732     inline _FIterator
 733     adjacent_find(_FIterator __begin, _FIterator __end,
 734                   _BinaryPredicate __binary_pred,
 735                   __gnu_parallel::sequential_tag)
 736     { return _GLIBCXX_STD_A::adjacent_find(__begin, __end, __binary_pred); }
 737
 738   // Parallel algorithm for random access iterators
 739   template<typename _RAIter>
 740     _RAIter
 741     __adjacent_find_switch(_RAIter __begin, _RAIter __end,
 742                            random_access_iterator_tag)
 743     {
 744       typedef iterator_traits<_RAIter> _TraitsType;
 745       typedef typename _TraitsType::value_type _ValueType;
 746
 747       if (_GLIBCXX_PARALLEL_CONDITION(true))
 748         {
 749           _RAIter __spot = __gnu_parallel::
 750               __find_template(
 751                 __begin, __end - 1, __begin, equal_to<_ValueType>(),
 752                 __gnu_parallel::__adjacent_find_selector())
 753             .first;
 754           if (__spot == (__end - 1))
 755             return __end;
 756           else
 757             return __spot;
 758         }
 759       else
 760         return adjacent_find(__begin, __end, __gnu_parallel::sequential_tag());
 761     }
 762
 763   // Sequential fallback for input iterator case
 764   template<typename _FIterator, typename _IteratorTag>
 765     inline _FIterator
 766     __adjacent_find_switch(_FIterator __begin, _FIterator __end,
 767                            _IteratorTag)
 768     { return adjacent_find(__begin, __end, __gnu_parallel::sequential_tag()); }
 769
 770   // Public interface
 771   template<typename _FIterator>
 772     inline _FIterator
 773     adjacent_find(_FIterator __begin, _FIterator __end)
 774     {
 775       return __adjacent_find_switch(__begin, __end,
 776                                     std::__iterator_category(__begin));
 777     }
 778
 779   // Sequential fallback for input iterator case
 780   template<typename _FIterator, typename _BinaryPredicate,
 781            typename _IteratorTag>
 782     inline _FIterator
 783     __adjacent_find_switch(_FIterator __begin, _FIterator __end,
 784                            _BinaryPredicate __pred, _IteratorTag)
 785     { return adjacent_find(__begin, __end, __pred,
 786                            __gnu_parallel::sequential_tag()); }
 787
 788   // Parallel algorithm for random access iterators
 789   template<typename _RAIter, typename _BinaryPredicate>
 790     _RAIter
 791     __adjacent_find_switch(_RAIter __begin, _RAIter __end,
 792                            _BinaryPredicate __pred, random_access_iterator_tag)
 793     {
 794       if (_GLIBCXX_PARALLEL_CONDITION(true))
 795         return __gnu_parallel::__find_template(__begin, __end, __begin, __pred,
 796                                              __gnu_parallel::
 797                                              __adjacent_find_selector()).first;
 798       else
 799         return adjacent_find(__begin, __end, __pred,
 800                              __gnu_parallel::sequential_tag());
 801     }
 802
 803   // Public interface
 804   template<typename _FIterator, typename _BinaryPredicate>
 805     inline _FIterator
 806     adjacent_find(_FIterator __begin, _FIterator __end,
 807                   _BinaryPredicate __pred)
 808     {
 809       return __adjacent_find_switch(__begin, __end, __pred,
 810                                     std::__iterator_category(__begin));
 811     }
 812
 813   // Sequential fallback
 814   template<typename _IIter, typename _Tp>
 815     inline typename iterator_traits<_IIter>::difference_type
 816     count(_IIter __begin, _IIter __end, const _Tp& __value,
 817           __gnu_parallel::sequential_tag)
 818     { return _GLIBCXX_STD_A::count(__begin, __end, __value); }
 819
 820   // Parallel code for random access iterators
 821   template<typename _RAIter, typename _Tp>
 822     typename iterator_traits<_RAIter>::difference_type
 823     __count_switch(_RAIter __begin, _RAIter __end,
 824                    const _Tp& __value, random_access_iterator_tag,
 825                    __gnu_parallel::_Parallelism __parallelism_tag)
 826     {
 827       typedef iterator_traits<_RAIter> _TraitsType;
 828       typedef typename _TraitsType::value_type _ValueType;
 829       typedef typename _TraitsType::difference_type _DifferenceType;
 830       typedef __gnu_parallel::_SequenceIndex _SequenceIndex;
 831
 832       if (_GLIBCXX_PARALLEL_CONDITION(
 833             static_cast<_SequenceIndex>(__end - __begin)
 834             >= __gnu_parallel::_Settings::get().count_minimal_n
 835             && __gnu_parallel::__is_parallel(__parallelism_tag)))
 836         {
 837           __gnu_parallel::__count_selector<_RAIter, _DifferenceType>
 838             __functionality;
 839           _DifferenceType __res = 0;
 840           __gnu_parallel::
 841             __for_each_template_random_access(
 842               __begin, __end, __value, __functionality,
 843               std::plus<_SequenceIndex>(), __res, __res, -1,
 844               __parallelism_tag);
 845           return __res;
 846         }
 847       else
 848         return count(__begin, __end, __value,
 849                      __gnu_parallel::sequential_tag());
 850     }
 851
 852   // Sequential fallback for input iterator case.
 853   template<typename _IIter, typename _Tp, typename _IteratorTag>
 854     inline typename iterator_traits<_IIter>::difference_type
 855     __count_switch(_IIter __begin, _IIter __end, const _Tp& __value,
 856                    _IteratorTag)
 857     { return count(__begin, __end, __value, __gnu_parallel::sequential_tag());
 858       }
 859
 860   // Public interface.
 861   template<typename _IIter, typename _Tp>
 862     inline typename iterator_traits<_IIter>::difference_type
 863     count(_IIter __begin, _IIter __end, const _Tp& __value,
 864           __gnu_parallel::_Parallelism __parallelism_tag)
 865     {
 866       return __count_switch(__begin, __end, __value,
 867                             std::__iterator_category(__begin),
 868                             __parallelism_tag);
 869     }
 870
 871   template<typename _IIter, typename _Tp>
 872     inline typename iterator_traits<_IIter>::difference_type
 873     count(_IIter __begin, _IIter __end, const _Tp& __value)
 874     {
 875       return __count_switch(__begin, __end, __value,
 876                             std::__iterator_category(__begin));
 877     }
 878
 879
 880   // Sequential fallback.
 881   template<typename _IIter, typename _Predicate>
 882     inline typename iterator_traits<_IIter>::difference_type
 883     count_if(_IIter __begin, _IIter __end, _Predicate __pred,
 884              __gnu_parallel::sequential_tag)
 885     { return _GLIBCXX_STD_A::count_if(__begin, __end, __pred); }
 886
 887   // Parallel count_if for random access iterators
 888   template<typename _RAIter, typename _Predicate>
 889     typename iterator_traits<_RAIter>::difference_type
 890     __count_if_switch(_RAIter __begin, _RAIter __end,
 891                       _Predicate __pred, random_access_iterator_tag,
 892                       __gnu_parallel::_Parallelism __parallelism_tag)
 893     {
 894       typedef iterator_traits<_RAIter> _TraitsType;
 895       typedef typename _TraitsType::value_type _ValueType;
 896       typedef typename _TraitsType::difference_type _DifferenceType;
 897       typedef __gnu_parallel::_SequenceIndex _SequenceIndex;
 898
 899       if (_GLIBCXX_PARALLEL_CONDITION(
 900             static_cast<_SequenceIndex>(__end - __begin)
 901             >= __gnu_parallel::_Settings::get().count_minimal_n
 902             && __gnu_parallel::__is_parallel(__parallelism_tag)))
 903         {
 904           _DifferenceType __res = 0;
 905           __gnu_parallel::
 906             __count_if_selector<_RAIter, _DifferenceType>
 907             __functionality;
 908           __gnu_parallel::
 909             __for_each_template_random_access(
 910               __begin, __end, __pred, __functionality,
 911               std::plus<_SequenceIndex>(), __res, __res, -1,
 912               __parallelism_tag);
 913           return __res;
 914         }
 915       else
 916         return count_if(__begin, __end, __pred,
 917                         __gnu_parallel::sequential_tag());
 918     }
 919
 920   // Sequential fallback for input iterator case.
 921   template<typename _IIter, typename _Predicate, typename _IteratorTag>
 922     inline typename iterator_traits<_IIter>::difference_type
 923     __count_if_switch(_IIter __begin, _IIter __end, _Predicate __pred,
 924                       _IteratorTag)
 925     { return count_if(__begin, __end, __pred,
 926                       __gnu_parallel::sequential_tag()); }
 927
 928   // Public interface.
 929   template<typename _IIter, typename _Predicate>
 930     inline typename iterator_traits<_IIter>::difference_type
 931     count_if(_IIter __begin, _IIter __end, _Predicate __pred,
 932              __gnu_parallel::_Parallelism __parallelism_tag)
 933     {
 934       return __count_if_switch(__begin, __end, __pred,
 935                                std::__iterator_category(__begin),
 936                                __parallelism_tag);
 937     }
 938
 939   template<typename _IIter, typename _Predicate>
 940     inline typename iterator_traits<_IIter>::difference_type
 941     count_if(_IIter __begin, _IIter __end, _Predicate __pred)
 942     {
 943       return __count_if_switch(__begin, __end, __pred,
 944                                std::__iterator_category(__begin));
 945     }
 946
 947
 948   // Sequential fallback.
 949   template<typename _FIterator1, typename _FIterator2>
 950     inline _FIterator1
 951     search(_FIterator1 __begin1, _FIterator1 __end1,
 952            _FIterator2 __begin2, _FIterator2 __end2,
 953            __gnu_parallel::sequential_tag)
 954     { return _GLIBCXX_STD_A::search(__begin1, __end1, __begin2, __end2); }
 955
 956   // Parallel algorithm for random access iterator
 957   template<typename _RAIter1, typename _RAIter2>
 958     _RAIter1
 959     __search_switch(_RAIter1 __begin1, _RAIter1 __end1,
 960                     _RAIter2 __begin2, _RAIter2 __end2,
 961                     random_access_iterator_tag, random_access_iterator_tag)
 962     {
 963       typedef typename std::iterator_traits<_RAIter1>::value_type _ValueType1;
 964       typedef typename std::iterator_traits<_RAIter2>::value_type _ValueType2;
 965
 966       if (_GLIBCXX_PARALLEL_CONDITION(
 967                 static_cast<__gnu_parallel::_SequenceIndex>(__end1 - __begin1)
 968             >= __gnu_parallel::_Settings::get().search_minimal_n))
 969         return __gnu_parallel::
 970           __search_template(
 971             __begin1, __end1, __begin2, __end2,
 972             __gnu_parallel::_EqualTo<_ValueType1, _ValueType2>());
 973       else
 974         return search(__begin1, __end1, __begin2, __end2,
 975                       __gnu_parallel::sequential_tag());
 976     }
 977
 978   // Sequential fallback for input iterator case
 979   template<typename _FIterator1, typename _FIterator2,
 980            typename _IteratorTag1, typename _IteratorTag2>
 981     inline _FIterator1
 982     __search_switch(_FIterator1 __begin1, _FIterator1 __end1,
 983                     _FIterator2 __begin2, _FIterator2 __end2,
 984                     _IteratorTag1, _IteratorTag2)
 985     { return search(__begin1, __end1, __begin2, __end2,
 986                     __gnu_parallel::sequential_tag()); }
 987
 988   // Public interface.
 989   template<typename _FIterator1, typename _FIterator2>
 990     inline _FIterator1
 991     search(_FIterator1 __begin1, _FIterator1 __end1,
 992            _FIterator2 __begin2, _FIterator2 __end2)
 993     {
 994       return __search_switch(__begin1, __end1, __begin2, __end2,
 995                              std::__iterator_category(__begin1),
 996                              std::__iterator_category(__begin2));
 997     }
 998
 999   // Public interface.
1000   template<typename _FIterator1, typename _FIterator2,
1001            typename _BinaryPredicate>
1002     inline _FIterator1
1003     search(_FIterator1 __begin1, _FIterator1 __end1,
1004            _FIterator2 __begin2, _FIterator2 __end2,
1005            _BinaryPredicate __pred, __gnu_parallel::sequential_tag)
1006     { return _GLIBCXX_STD_A::search(
1007                                __begin1, __end1, __begin2, __end2, __pred); }
1008
1009   // Parallel algorithm for random access iterator.
1010   template<typename _RAIter1, typename _RAIter2,
1011            typename _BinaryPredicate>
1012     _RAIter1
1013     __search_switch(_RAIter1 __begin1, _RAIter1 __end1,
1014                     _RAIter2 __begin2, _RAIter2 __end2,
1015                     _BinaryPredicate __pred,
1016                     random_access_iterator_tag, random_access_iterator_tag)
1017     {
1018       if (_GLIBCXX_PARALLEL_CONDITION(
1019                 static_cast<__gnu_parallel::_SequenceIndex>(__end1 - __begin1)
1020             >= __gnu_parallel::_Settings::get().search_minimal_n))
1021         return __gnu_parallel::__search_template(__begin1, __end1,
1022                                                __begin2, __end2, __pred);
1023       else
1024         return search(__begin1, __end1, __begin2, __end2, __pred,
1025                       __gnu_parallel::sequential_tag());
1026     }
1027
1028   // Sequential fallback for input iterator case
1029   template<typename _FIterator1, typename _FIterator2,
1030            typename _BinaryPredicate, typename _IteratorTag1,
1031            typename _IteratorTag2>
1032     inline _FIterator1
1033     __search_switch(_FIterator1 __begin1, _FIterator1 __end1,
1034                     _FIterator2 __begin2, _FIterator2 __end2,
1035                     _BinaryPredicate __pred, _IteratorTag1, _IteratorTag2)
1036     { return search(__begin1, __end1, __begin2, __end2, __pred,
1037                     __gnu_parallel::sequential_tag()); }
1038
1039   // Public interface
1040   template<typename _FIterator1, typename _FIterator2,
1041            typename _BinaryPredicate>
1042     inline _FIterator1
1043     search(_FIterator1 __begin1, _FIterator1 __end1,
1044            _FIterator2 __begin2, _FIterator2 __end2,
1045            _BinaryPredicate  __pred)
1046     {
1047       return __search_switch(__begin1, __end1, __begin2, __end2, __pred,
1048                              std::__iterator_category(__begin1),
1049                              std::__iterator_category(__begin2));
1050     }
1051
1052   // Sequential fallback
1053   template<typename _FIterator, typename _Integer, typename _Tp>
1054     inline _FIterator
1055     search_n(_FIterator __begin, _FIterator __end, _Integer __count,
1056              const _Tp& __val, __gnu_parallel::sequential_tag)
1057     { return _GLIBCXX_STD_A::search_n(__begin, __end, __count, __val); }
1058
1059   // Sequential fallback
1060   template<typename _FIterator, typename _Integer, typename _Tp,
1061            typename _BinaryPredicate>
1062     inline _FIterator
1063     search_n(_FIterator __begin, _FIterator __end, _Integer __count,
1064              const _Tp& __val, _BinaryPredicate __binary_pred,
1065              __gnu_parallel::sequential_tag)
1066     { return _GLIBCXX_STD_A::search_n(
1067                __begin, __end, __count, __val, __binary_pred); }
1068
1069   // Public interface.
1070   template<typename _FIterator, typename _Integer, typename _Tp>
1071     inline _FIterator
1072     search_n(_FIterator __begin, _FIterator __end, _Integer __count,
1073              const _Tp& __val)
1074     {
1075       typedef typename iterator_traits<_FIterator>::value_type _ValueType;
1076       return __gnu_parallel::search_n(__begin, __end, __count, __val,
1077                       __gnu_parallel::_EqualTo<_ValueType, _Tp>());
1078     }
1079
1080   // Parallel algorithm for random access iterators.
1081   template<typename _RAIter, typename _Integer,
1082            typename _Tp, typename _BinaryPredicate>
1083     _RAIter
1084     __search_n_switch(_RAIter __begin, _RAIter __end, _Integer __count,
1085                       const _Tp& __val, _BinaryPredicate __binary_pred,
1086                       random_access_iterator_tag)
1087     {
1088       if (_GLIBCXX_PARALLEL_CONDITION(
1089                 static_cast<__gnu_parallel::_SequenceIndex>(__end - __begin)
1090             >= __gnu_parallel::_Settings::get().search_minimal_n))
1091         {
1092           __gnu_parallel::_PseudoSequence<_Tp, _Integer> __ps(__val, __count);
1093           return __gnu_parallel::__search_template(
1094                    __begin, __end, __ps.begin(), __ps.end(), __binary_pred);
1095         }
1096       else
1097         return _GLIBCXX_STD_A::search_n(__begin, __end, __count, __val,
1098                                         __binary_pred);
1099     }
1100
1101   // Sequential fallback for input iterator case.
1102   template<typename _FIterator, typename _Integer, typename _Tp,
1103            typename _BinaryPredicate, typename _IteratorTag>
1104     inline _FIterator
1105     __search_n_switch(_FIterator __begin, _FIterator __end, _Integer __count,
1106                       const _Tp& __val, _BinaryPredicate __binary_pred,
1107                       _IteratorTag)
1108     { return _GLIBCXX_STD_A::search_n(__begin, __end, __count, __val,
1109                                       __binary_pred); }
1110
1111   // Public interface.
1112   template<typename _FIterator, typename _Integer, typename _Tp,
1113            typename _BinaryPredicate>
1114     inline _FIterator
1115     search_n(_FIterator __begin, _FIterator __end, _Integer __count,
1116              const _Tp& __val, _BinaryPredicate __binary_pred)
1117     {
1118       return __search_n_switch(__begin, __end, __count, __val, __binary_pred,
1119                                std::__iterator_category(__begin));
1120     }
1121
1122
1123   // Sequential fallback.
1124   template<typename _IIter, typename _OutputIterator,
1125            typename _UnaryOperation>
1126     inline _OutputIterator
1127     transform(_IIter __begin, _IIter __end, _OutputIterator __result,
1128               _UnaryOperation __unary_op, __gnu_parallel::sequential_tag)
1129     { return _GLIBCXX_STD_A::transform(__begin, __end, __result, __unary_op); }
1130
1131   // Parallel unary transform for random access iterators.
1132   template<typename _RAIter1, typename _RAIter2,
1133            typename _UnaryOperation>
1134     _RAIter2
1135     __transform1_switch(_RAIter1 __begin, _RAIter1 __end,
1136                         _RAIter2 __result, _UnaryOperation __unary_op,
1137                         random_access_iterator_tag, random_access_iterator_tag,
1138                         __gnu_parallel::_Parallelism __parallelism_tag)
1139     {
1140       if (_GLIBCXX_PARALLEL_CONDITION(
1141             static_cast<__gnu_parallel::_SequenceIndex>(__end - __begin)
1142             >= __gnu_parallel::_Settings::get().transform_minimal_n
1143             && __gnu_parallel::__is_parallel(__parallelism_tag)))
1144         {
1145           bool __dummy = true;
1146           typedef __gnu_parallel::_IteratorPair<_RAIter1,
1147             _RAIter2, random_access_iterator_tag> _ItTrip;
1148           _ItTrip __begin_pair(__begin, __result),
1149                   __end_pair(__end, __result + (__end - __begin));
1150           __gnu_parallel::__transform1_selector<_ItTrip> __functionality;
1151           __gnu_parallel::
1152             __for_each_template_random_access(
1153               __begin_pair, __end_pair, __unary_op, __functionality,
1154               __gnu_parallel::_DummyReduct(),
1155               __dummy, __dummy, -1, __parallelism_tag);
1156           return __functionality._M_finish_iterator;
1157         }
1158       else
1159         return transform(__begin, __end, __result, __unary_op,
1160                          __gnu_parallel::sequential_tag());
1161     }
1162
1163   // Sequential fallback for input iterator case.
1164   template<typename _RAIter1, typename _RAIter2,
1165            typename _UnaryOperation, typename _IteratorTag1,
1166            typename _IteratorTag2>
1167     inline _RAIter2
1168     __transform1_switch(_RAIter1 __begin, _RAIter1 __end,
1169                         _RAIter2 __result, _UnaryOperation __unary_op,
1170                         _IteratorTag1, _IteratorTag2)
1171     { return transform(__begin, __end, __result, __unary_op,
1172                        __gnu_parallel::sequential_tag()); }
1173
1174   // Public interface.
1175   template<typename _IIter, typename _OutputIterator,
1176            typename _UnaryOperation>
1177     inline _OutputIterator
1178     transform(_IIter __begin, _IIter __end, _OutputIterator __result,
1179               _UnaryOperation __unary_op,
1180               __gnu_parallel::_Parallelism __parallelism_tag)
1181     {
1182       return __transform1_switch(__begin, __end, __result, __unary_op,
1183                                  std::__iterator_category(__begin),
1184                                  std::__iterator_category(__result),
1185                                  __parallelism_tag);
1186     }
1187
1188   template<typename _IIter, typename _OutputIterator,
1189            typename _UnaryOperation>
1190     inline _OutputIterator
1191     transform(_IIter __begin, _IIter __end, _OutputIterator __result,
1192               _UnaryOperation __unary_op)
1193     {
1194       return __transform1_switch(__begin, __end, __result, __unary_op,
1195                                  std::__iterator_category(__begin),
1196                                  std::__iterator_category(__result));
1197     }
1198
1199
1200   // Sequential fallback
1201   template<typename _IIter1, typename _IIter2,
1202            typename _OutputIterator, typename _BinaryOperation>
1203     inline _OutputIterator
1204     transform(_IIter1 __begin1, _IIter1 __end1,
1205               _IIter2 __begin2, _OutputIterator __result,
1206               _BinaryOperation __binary_op, __gnu_parallel::sequential_tag)
1207     { return _GLIBCXX_STD_A::transform(__begin1, __end1,
1208                                        __begin2, __result, __binary_op); }
1209
1210   // Parallel binary transform for random access iterators.
1211   template<typename _RAIter1, typename _RAIter2,
1212            typename _RAIter3, typename _BinaryOperation>
1213     _RAIter3
1214     __transform2_switch(_RAIter1 __begin1, _RAIter1 __end1,
1215                         _RAIter2 __begin2,
1216                         _RAIter3 __result, _BinaryOperation __binary_op,
1217                         random_access_iterator_tag, random_access_iterator_tag,
1218                         random_access_iterator_tag,
1219                         __gnu_parallel::_Parallelism __parallelism_tag)
1220     {
1221       if (_GLIBCXX_PARALLEL_CONDITION(
1222             (__end1 - __begin1) >=
1223                 __gnu_parallel::_Settings::get().transform_minimal_n
1224             && __gnu_parallel::__is_parallel(__parallelism_tag)))
1225         {
1226           bool __dummy = true;
1227           typedef __gnu_parallel::_IteratorTriple<_RAIter1,
1228             _RAIter2, _RAIter3,
1229             random_access_iterator_tag> _ItTrip;
1230           _ItTrip __begin_triple(__begin1, __begin2, __result),
1231             __end_triple(__end1, __begin2 + (__end1 - __begin1),
1232                        __result + (__end1 - __begin1));
1233           __gnu_parallel::__transform2_selector<_ItTrip> __functionality;
1234           __gnu_parallel::
1235             __for_each_template_random_access(__begin_triple, __end_triple,
1236                                               __binary_op, __functionality,
1237                                               __gnu_parallel::_DummyReduct(),
1238                                               __dummy, __dummy, -1,
1239                                               __parallelism_tag);
1240           return __functionality._M_finish_iterator;
1241         }
1242       else
1243         return transform(__begin1, __end1, __begin2, __result, __binary_op,
1244                          __gnu_parallel::sequential_tag());
1245     }
1246
1247   // Sequential fallback for input iterator case.
1248   template<typename _IIter1, typename _IIter2,
1249            typename _OutputIterator, typename _BinaryOperation,
1250            typename _Tag1, typename _Tag2, typename _Tag3>
1251     inline _OutputIterator
1252     __transform2_switch(_IIter1 __begin1, _IIter1 __end1,
1253                         _IIter2 __begin2, _OutputIterator __result,
1254                         _BinaryOperation __binary_op, _Tag1, _Tag2, _Tag3)
1255     { return transform(__begin1, __end1, __begin2, __result, __binary_op,
1256                        __gnu_parallel::sequential_tag()); }
1257
1258   // Public interface.
1259   template<typename _IIter1, typename _IIter2,
1260            typename _OutputIterator, typename _BinaryOperation>
1261     inline _OutputIterator
1262     transform(_IIter1 __begin1, _IIter1 __end1,
1263               _IIter2 __begin2, _OutputIterator __result,
1264               _BinaryOperation __binary_op,
1265               __gnu_parallel::_Parallelism __parallelism_tag)
1266     {
1267       return __transform2_switch(
1268                __begin1, __end1, __begin2, __result, __binary_op,
1269                std::__iterator_category(__begin1),
1270                std::__iterator_category(__begin2),
1271                std::__iterator_category(__result),
1272                __parallelism_tag);
1273     }
1274
1275   template<typename _IIter1, typename _IIter2,
1276            typename _OutputIterator, typename _BinaryOperation>
1277     inline _OutputIterator
1278     transform(_IIter1 __begin1, _IIter1 __end1,
1279               _IIter2 __begin2, _OutputIterator __result,
1280               _BinaryOperation __binary_op)
1281     {
1282       return __transform2_switch(
1283                __begin1, __end1, __begin2, __result, __binary_op,
1284                std::__iterator_category(__begin1),
1285                std::__iterator_category(__begin2),
1286                std::__iterator_category(__result));
1287     }
1288
1289   // Sequential fallback
1290   template<typename _FIterator, typename _Tp>
1291     inline void
1292     replace(_FIterator __begin, _FIterator __end, const _Tp& __old_value,
1293             const _Tp& __new_value, __gnu_parallel::sequential_tag)
1294     { _GLIBCXX_STD_A::replace(__begin, __end, __old_value, __new_value); }
1295
1296   // Sequential fallback for input iterator case
1297   template<typename _FIterator, typename _Tp, typename _IteratorTag>
1298     inline void
1299     __replace_switch(_FIterator __begin, _FIterator __end,
1300                      const _Tp& __old_value, const _Tp& __new_value,
1301                      _IteratorTag)
1302     { replace(__begin, __end, __old_value, __new_value,
1303               __gnu_parallel::sequential_tag()); }
1304
1305   // Parallel replace for random access iterators
1306   template<typename _RAIter, typename _Tp>
1307     inline void
1308     __replace_switch(_RAIter __begin, _RAIter __end,
1309                      const _Tp& __old_value, const _Tp& __new_value,
1310                      random_access_iterator_tag,
1311                      __gnu_parallel::_Parallelism __parallelism_tag)
1312     {
1313       // XXX parallel version is where?
1314       replace(__begin, __end, __old_value, __new_value,
1315               __gnu_parallel::sequential_tag());
1316     }
1317
1318   // Public interface
1319   template<typename _FIterator, typename _Tp>
1320     inline void
1321     replace(_FIterator __begin, _FIterator __end, const _Tp& __old_value,
1322             const _Tp& __new_value,
1323             __gnu_parallel::_Parallelism __parallelism_tag)
1324     {
1325       __replace_switch(__begin, __end, __old_value, __new_value,
1326                        std::__iterator_category(__begin),
1327                        __parallelism_tag);
1328     }
1329
1330   template<typename _FIterator, typename _Tp>
1331     inline void
1332     replace(_FIterator __begin, _FIterator __end, const _Tp& __old_value,
1333             const _Tp& __new_value)
1334     {
1335       __replace_switch(__begin, __end, __old_value, __new_value,
1336                        std::__iterator_category(__begin));
1337     }
1338
1339
1340   // Sequential fallback
1341   template<typename _FIterator, typename _Predicate, typename _Tp>
1342     inline void
1343     replace_if(_FIterator __begin, _FIterator __end, _Predicate __pred,
1344                const _Tp& __new_value, __gnu_parallel::sequential_tag)
1345     { _GLIBCXX_STD_A::replace_if(__begin, __end, __pred, __new_value); }
1346
1347   // Sequential fallback for input iterator case
1348   template<typename _FIterator, typename _Predicate, typename _Tp,
1349            typename _IteratorTag>
1350     inline void
1351     __replace_if_switch(_FIterator __begin, _FIterator __end,
1352                         _Predicate __pred, const _Tp& __new_value, _IteratorTag)
1353     { replace_if(__begin, __end, __pred, __new_value,
1354                  __gnu_parallel::sequential_tag()); }
1355
1356   // Parallel algorithm for random access iterators.
1357   template<typename _RAIter, typename _Predicate, typename _Tp>
1358     void
1359     __replace_if_switch(_RAIter __begin, _RAIter __end,
1360                         _Predicate __pred, const _Tp& __new_value,
1361                         random_access_iterator_tag,
1362                         __gnu_parallel::_Parallelism __parallelism_tag)
1363     {
1364       if (_GLIBCXX_PARALLEL_CONDITION(
1365             static_cast<__gnu_parallel::_SequenceIndex>(__end - __begin)
1366             >= __gnu_parallel::_Settings::get().replace_minimal_n
1367             && __gnu_parallel::__is_parallel(__parallelism_tag)))
1368         {
1369           bool __dummy;
1370           __gnu_parallel::
1371             __replace_if_selector<_RAIter, _Predicate, _Tp>
1372             __functionality(__new_value);
1373           __gnu_parallel::
1374             __for_each_template_random_access(
1375               __begin, __end, __pred, __functionality,
1376               __gnu_parallel::_DummyReduct(),
1377               true, __dummy, -1, __parallelism_tag);
1378         }
1379       else
1380         replace_if(__begin, __end, __pred, __new_value,
1381                    __gnu_parallel::sequential_tag());
1382     }
1383
1384   // Public interface.
1385   template<typename _FIterator, typename _Predicate, typename _Tp>
1386     inline void
1387     replace_if(_FIterator __begin, _FIterator __end,
1388                _Predicate __pred, const _Tp& __new_value,
1389                __gnu_parallel::_Parallelism __parallelism_tag)
1390     {
1391       __replace_if_switch(__begin, __end, __pred, __new_value,
1392                           std::__iterator_category(__begin),
1393                           __parallelism_tag);
1394     }
1395
1396   template<typename _FIterator, typename _Predicate, typename _Tp>
1397     inline void
1398     replace_if(_FIterator __begin, _FIterator __end,
1399                _Predicate __pred, const _Tp& __new_value)
1400     {
1401       __replace_if_switch(__begin, __end, __pred, __new_value,
1402                           std::__iterator_category(__begin));
1403     }
1404
1405   // Sequential fallback
1406   template<typename _FIterator, typename _Generator>
1407     inline void
1408     generate(_FIterator __begin, _FIterator __end, _Generator __gen,
1409              __gnu_parallel::sequential_tag)
1410     { _GLIBCXX_STD_A::generate(__begin, __end, __gen); }
1411
1412   // Sequential fallback for input iterator case.
1413   template<typename _FIterator, typename _Generator, typename _IteratorTag>
1414     inline void
1415     __generate_switch(_FIterator __begin, _FIterator __end, _Generator __gen,
1416                       _IteratorTag)
1417     { generate(__begin, __end, __gen, __gnu_parallel::sequential_tag()); }
1418
1419   // Parallel algorithm for random access iterators.
1420   template<typename _RAIter, typename _Generator>
1421     void
1422     __generate_switch(_RAIter __begin, _RAIter __end,
1423                       _Generator __gen, random_access_iterator_tag,
1424                       __gnu_parallel::_Parallelism __parallelism_tag)
1425     {
1426       if (_GLIBCXX_PARALLEL_CONDITION(
1427             static_cast<__gnu_parallel::_SequenceIndex>(__end - __begin)
1428             >= __gnu_parallel::_Settings::get().generate_minimal_n
1429             && __gnu_parallel::__is_parallel(__parallelism_tag)))
1430         {
1431           bool __dummy;
1432           __gnu_parallel::__generate_selector<_RAIter>
1433             __functionality;
1434           __gnu_parallel::
1435             __for_each_template_random_access(
1436               __begin, __end, __gen, __functionality,
1437               __gnu_parallel::_DummyReduct(),
1438               true, __dummy, -1, __parallelism_tag);
1439         }
1440       else
1441         generate(__begin, __end, __gen, __gnu_parallel::sequential_tag());
1442     }
1443
1444   // Public interface.
1445   template<typename _FIterator, typename _Generator>
1446     inline void
1447     generate(_FIterator __begin, _FIterator __end,
1448              _Generator __gen, __gnu_parallel::_Parallelism __parallelism_tag)
1449     {
1450       __generate_switch(__begin, __end, __gen,
1451                         std::__iterator_category(__begin),
1452                         __parallelism_tag);
1453     }
1454
1455   template<typename _FIterator, typename _Generator>
1456     inline void
1457     generate(_FIterator __begin, _FIterator __end, _Generator __gen)
1458     {
1459       __generate_switch(__begin, __end, __gen,
1460                         std::__iterator_category(__begin));
1461     }
1462
1463
1464   // Sequential fallback.
1465   template<typename _OutputIterator, typename _Size, typename _Generator>
1466     inline _OutputIterator
1467     generate_n(_OutputIterator __begin, _Size __n, _Generator __gen,
1468                __gnu_parallel::sequential_tag)
1469     { return _GLIBCXX_STD_A::generate_n(__begin, __n, __gen); }
1470
1471   // Sequential fallback for input iterator case.
1472   template<typename _OutputIterator, typename _Size, typename _Generator,
1473            typename _IteratorTag>
1474     inline _OutputIterator
1475     __generate_n_switch(_OutputIterator __begin, _Size __n, _Generator __gen,
1476                         _IteratorTag)
1477     { return generate_n(__begin, __n, __gen,
1478                         __gnu_parallel::sequential_tag()); }
1479
1480   // Parallel algorithm for random access iterators.
1481   template<typename _RAIter, typename _Size, typename _Generator>
1482     inline _RAIter
1483     __generate_n_switch(_RAIter __begin, _Size __n, _Generator __gen,
1484                         random_access_iterator_tag,
1485                         __gnu_parallel::_Parallelism __parallelism_tag)
1486     {
1487       // XXX parallel version is where?
1488       return generate_n(__begin, __n, __gen, __gnu_parallel::sequential_tag());
1489     }
1490
1491   // Public interface.
1492   template<typename _OutputIterator, typename _Size, typename _Generator>
1493     inline _OutputIterator
1494     generate_n(_OutputIterator __begin, _Size __n, _Generator __gen,
1495                __gnu_parallel::_Parallelism __parallelism_tag)
1496     {
1497       return __generate_n_switch(__begin, __n, __gen,
1498                                  std::__iterator_category(__begin),
1499                                  __parallelism_tag);
1500     }
1501
1502   template<typename _OutputIterator, typename _Size, typename _Generator>
1503     inline _OutputIterator
1504     generate_n(_OutputIterator __begin, _Size __n, _Generator __gen)
1505     {
1506       return __generate_n_switch(__begin, __n, __gen,
1507                                  std::__iterator_category(__begin));
1508     }
1509
1510
1511   // Sequential fallback.
1512   template<typename _RAIter>
1513     inline void
1514     random_shuffle(_RAIter __begin, _RAIter __end,
1515                    __gnu_parallel::sequential_tag)
1516     { _GLIBCXX_STD_A::random_shuffle(__begin, __end); }
1517
1518   // Sequential fallback.
1519   template<typename _RAIter, typename _RandomNumberGenerator>
1520     inline void
1521     random_shuffle(_RAIter __begin, _RAIter __end,
1522                    _RandomNumberGenerator& __rand,
1523                    __gnu_parallel::sequential_tag)
1524     { _GLIBCXX_STD_A::random_shuffle(__begin, __end, __rand); }
1525
1526
1527   /** @brief Functor wrapper for std::rand(). */
1528   template<typename _MustBeInt = int>
1529     struct _CRandNumber
1530     {
1531       int
1532       operator()(int __limit)
1533       { return rand() % __limit; }
1534     };
1535
1536   // Fill in random number generator.
1537   template<typename _RAIter>
1538     inline void
1539     random_shuffle(_RAIter __begin, _RAIter __end)
1540     {
1541       _CRandNumber<> __r;
1542       // Parallelization still possible.
1543       __gnu_parallel::random_shuffle(__begin, __end, __r);
1544     }
1545
1546   // Parallel algorithm for random access iterators.
1547   template<typename _RAIter, typename _RandomNumberGenerator>
1548     void
1549     random_shuffle(_RAIter __begin, _RAIter __end,
1550 #if __cplusplus >= 201103L
1551                    _RandomNumberGenerator&& __rand)
1552 #else
1553                    _RandomNumberGenerator& __rand)
1554 #endif
1555     {
1556       if (__begin == __end)
1557         return;
1558       if (_GLIBCXX_PARALLEL_CONDITION(
1559             static_cast<__gnu_parallel::_SequenceIndex>(__end - __begin)
1560             >= __gnu_parallel::_Settings::get().random_shuffle_minimal_n))
1561         __gnu_parallel::__parallel_random_shuffle(__begin, __end, __rand);
1562       else
1563         __gnu_parallel::__sequential_random_shuffle(__begin, __end, __rand);
1564     }
1565
1566   // Sequential fallback.
1567   template<typename _FIterator, typename _Predicate>
1568     inline _FIterator
1569     partition(_FIterator __begin, _FIterator __end,
1570               _Predicate __pred, __gnu_parallel::sequential_tag)
1571     { return _GLIBCXX_STD_A::partition(__begin, __end, __pred); }
1572
1573   // Sequential fallback for input iterator case.
1574   template<typename _FIterator, typename _Predicate, typename _IteratorTag>
1575     inline _FIterator
1576     __partition_switch(_FIterator __begin, _FIterator __end,
1577                        _Predicate __pred, _IteratorTag)
1578     { return partition(__begin, __end, __pred,
1579                        __gnu_parallel::sequential_tag()); }
1580
1581   // Parallel algorithm for random access iterators.
1582   template<typename _RAIter, typename _Predicate>
1583     _RAIter
1584     __partition_switch(_RAIter __begin, _RAIter __end,
1585                        _Predicate __pred, random_access_iterator_tag)
1586     {
1587       if (_GLIBCXX_PARALLEL_CONDITION(
1588             static_cast<__gnu_parallel::_SequenceIndex>(__end - __begin)
1589             >= __gnu_parallel::_Settings::get().partition_minimal_n))
1590         {
1591           typedef typename std::iterator_traits<_RAIter>::
1592             difference_type _DifferenceType;
1593           _DifferenceType __middle = __gnu_parallel::
1594             __parallel_partition(__begin, __end, __pred,
1595                                __gnu_parallel::__get_max_threads());
1596           return __begin + __middle;
1597         }
1598       else
1599         return partition(__begin, __end, __pred,
1600                          __gnu_parallel::sequential_tag());
1601     }
1602
1603   // Public interface.
1604   template<typename _FIterator, typename _Predicate>
1605     inline _FIterator
1606     partition(_FIterator __begin, _FIterator __end, _Predicate __pred)
1607     {
1608       return __partition_switch(__begin, __end, __pred,
1609                                 std::__iterator_category(__begin));
1610     }
1611
1612   // sort interface
1613
1614   // Sequential fallback
1615   template<typename _RAIter>
1616     inline void
1617     sort(_RAIter __begin, _RAIter __end,
1618          __gnu_parallel::sequential_tag)
1619     { _GLIBCXX_STD_A::sort(__begin, __end); }
1620
1621   // Sequential fallback
1622   template<typename _RAIter, typename _Compare>
1623     inline void
1624     sort(_RAIter __begin, _RAIter __end, _Compare __comp,
1625          __gnu_parallel::sequential_tag)
1626     { _GLIBCXX_STD_A::sort<_RAIter, _Compare>(__begin, __end,
1627                                                              __comp); }
1628
1629   // Public interface
1630   template<typename _RAIter, typename _Compare,
1631            typename _Parallelism>
1632     void
1633     sort(_RAIter __begin, _RAIter __end, _Compare __comp,
1634          _Parallelism __parallelism)
1635   {
1636     typedef typename iterator_traits<_RAIter>::value_type _ValueType;
1637
1638     if (__begin != __end)
1639       {
1640         if (_GLIBCXX_PARALLEL_CONDITION(
1641             static_cast<__gnu_parallel::_SequenceIndex>(__end - __begin) >=
1642               __gnu_parallel::_Settings::get().sort_minimal_n))
1643           __gnu_parallel::__parallel_sort<false>(
1644                             __begin, __end, __comp, __parallelism);
1645         else
1646           sort(__begin, __end, __comp, __gnu_parallel::sequential_tag());
1647       }
1648   }
1649
1650   // Public interface, insert default comparator
1651   template<typename _RAIter>
1652     inline void
1653     sort(_RAIter __begin, _RAIter __end)
1654     {
1655       typedef typename iterator_traits<_RAIter>::value_type _ValueType;
1656       sort(__begin, __end, std::less<_ValueType>(),
1657            __gnu_parallel::default_parallel_tag());
1658     }
1659
1660   // Public interface, insert default comparator
1661   template<typename _RAIter>
1662     inline void
1663     sort(_RAIter __begin, _RAIter __end,
1664          __gnu_parallel::default_parallel_tag __parallelism)
1665     {
1666       typedef typename iterator_traits<_RAIter>::value_type _ValueType;
1667       sort(__begin, __end, std::less<_ValueType>(), __parallelism);
1668     }
1669
1670   // Public interface, insert default comparator
1671   template<typename _RAIter>
1672     inline void
1673     sort(_RAIter __begin, _RAIter __end,
1674          __gnu_parallel::parallel_tag __parallelism)
1675     {
1676       typedef typename iterator_traits<_RAIter>::value_type _ValueType;
1677       sort(__begin, __end, std::less<_ValueType>(), __parallelism);
1678     }
1679
1680   // Public interface, insert default comparator
1681   template<typename _RAIter>
1682     inline void
1683     sort(_RAIter __begin, _RAIter __end,
1684          __gnu_parallel::multiway_mergesort_tag __parallelism)
1685     {
1686       typedef typename iterator_traits<_RAIter>::value_type _ValueType;
1687       sort(__begin, __end, std::less<_ValueType>(), __parallelism);
1688     }
1689
1690   // Public interface, insert default comparator
1691   template<typename _RAIter>
1692     inline void
1693     sort(_RAIter __begin, _RAIter __end,
1694          __gnu_parallel::multiway_mergesort_sampling_tag __parallelism)
1695     {
1696       typedef typename iterator_traits<_RAIter>::value_type _ValueType;
1697       sort(__begin, __end, std::less<_ValueType>(), __parallelism);
1698     }
1699
1700   // Public interface, insert default comparator
1701   template<typename _RAIter>
1702     inline void
1703     sort(_RAIter __begin, _RAIter __end,
1704          __gnu_parallel::multiway_mergesort_exact_tag __parallelism)
1705     {
1706       typedef typename iterator_traits<_RAIter>::value_type _ValueType;
1707       sort(__begin, __end, std::less<_ValueType>(), __parallelism);
1708     }
1709
1710   // Public interface, insert default comparator
1711   template<typename _RAIter>
1712     inline void
1713     sort(_RAIter __begin, _RAIter __end,
1714          __gnu_parallel::quicksort_tag __parallelism)
1715     {
1716       typedef typename iterator_traits<_RAIter>::value_type _ValueType;
1717       sort(__begin, __end, std::less<_ValueType>(), __parallelism);
1718     }
1719
1720   // Public interface, insert default comparator
1721   template<typename _RAIter>
1722     inline void
1723     sort(_RAIter __begin, _RAIter __end,
1724          __gnu_parallel::balanced_quicksort_tag __parallelism)
1725     {
1726       typedef typename iterator_traits<_RAIter>::value_type _ValueType;
1727       sort(__begin, __end, std::less<_ValueType>(), __parallelism);
1728     }
1729
1730   // Public interface
1731   template<typename _RAIter, typename _Compare>
1732     void
1733     sort(_RAIter __begin, _RAIter __end, _Compare __comp)
1734     {
1735       typedef typename iterator_traits<_RAIter>::value_type _ValueType;
1736       sort(__begin, __end, __comp, __gnu_parallel::default_parallel_tag());
1737     }
1738
1739   // stable_sort interface
1740
1741
1742   // Sequential fallback
1743   template<typename _RAIter>
1744     inline void
1745     stable_sort(_RAIter __begin, _RAIter __end,
1746                 __gnu_parallel::sequential_tag)
1747     { _GLIBCXX_STD_A::stable_sort(__begin, __end); }
1748
1749   // Sequential fallback
1750   template<typename _RAIter, typename _Compare>
1751     inline void
1752     stable_sort(_RAIter __begin, _RAIter __end,
1753                 _Compare __comp, __gnu_parallel::sequential_tag)
1754     { _GLIBCXX_STD_A::stable_sort<_RAIter, _Compare>(__begin, __end, __comp); }
1755
1756   // Public interface
1757   template<typename _RAIter, typename _Compare,
1758            typename _Parallelism>
1759     void
1760     stable_sort(_RAIter __begin, _RAIter __end,
1761                 _Compare __comp, _Parallelism __parallelism)
1762     {
1763       typedef iterator_traits<_RAIter> _TraitsType;
1764       typedef typename _TraitsType::value_type _ValueType;
1765
1766       if (__begin != __end)
1767         {
1768           if (_GLIBCXX_PARALLEL_CONDITION(
1769                 static_cast<__gnu_parallel::_SequenceIndex>(__end - __begin) >=
1770                 __gnu_parallel::_Settings::get().sort_minimal_n))
1771             __gnu_parallel::__parallel_sort<true>(__begin, __end,
1772                                                   __comp, __parallelism);
1773           else
1774             stable_sort(__begin, __end, __comp,
1775                         __gnu_parallel::sequential_tag());
1776         }
1777     }
1778
1779   // Public interface, insert default comparator
1780   template<typename _RAIter>
1781     inline void
1782     stable_sort(_RAIter __begin, _RAIter __end)
1783     {
1784       typedef typename iterator_traits<_RAIter>::value_type _ValueType;
1785       stable_sort(__begin, __end, std::less<_ValueType>(),
1786                   __gnu_parallel::default_parallel_tag());
1787     }
1788
1789   // Public interface, insert default comparator
1790   template<typename _RAIter>
1791     inline void
1792     stable_sort(_RAIter __begin, _RAIter __end,
1793                 __gnu_parallel::default_parallel_tag __parallelism)
1794     {
1795       typedef typename iterator_traits<_RAIter>::value_type _ValueType;
1796       stable_sort(__begin, __end, std::less<_ValueType>(), __parallelism);
1797     }
1798
1799   // Public interface, insert default comparator
1800   template<typename _RAIter>
1801     inline void
1802     stable_sort(_RAIter __begin, _RAIter __end,
1803                 __gnu_parallel::parallel_tag __parallelism)
1804     {
1805       typedef typename iterator_traits<_RAIter>::value_type _ValueType;
1806       stable_sort(__begin, __end, std::less<_ValueType>(), __parallelism);
1807     }
1808
1809   // Public interface, insert default comparator
1810   template<typename _RAIter>
1811     inline void
1812     stable_sort(_RAIter __begin, _RAIter __end,
1813                 __gnu_parallel::multiway_mergesort_tag __parallelism)
1814     {
1815       typedef typename iterator_traits<_RAIter>::value_type _ValueType;
1816       stable_sort(__begin, __end, std::less<_ValueType>(), __parallelism);
1817     }
1818
1819   // Public interface, insert default comparator
1820   template<typename _RAIter>
1821     inline void
1822     stable_sort(_RAIter __begin, _RAIter __end,
1823                 __gnu_parallel::quicksort_tag __parallelism)
1824     {
1825       typedef typename iterator_traits<_RAIter>::value_type _ValueType;
1826       stable_sort(__begin, __end, std::less<_ValueType>(), __parallelism);
1827     }
1828
1829   // Public interface, insert default comparator
1830   template<typename _RAIter>
1831     inline void
1832     stable_sort(_RAIter __begin, _RAIter __end,
1833                 __gnu_parallel::balanced_quicksort_tag __parallelism)
1834     {
1835       typedef typename iterator_traits<_RAIter>::value_type _ValueType;
1836       stable_sort(__begin, __end, std::less<_ValueType>(), __parallelism);
1837     }
1838
1839   // Public interface
1840   template<typename _RAIter, typename _Compare>
1841     void
1842     stable_sort(_RAIter __begin, _RAIter __end, _Compare __comp)
1843     {
1844       stable_sort(
1845         __begin, __end, __comp, __gnu_parallel::default_parallel_tag());
1846     }
1847
1848   // Sequential fallback
1849   template<typename _IIter1, typename _IIter2,
1850            typename _OutputIterator>
1851     inline _OutputIterator
1852     merge(_IIter1 __begin1, _IIter1 __end1, _IIter2 __begin2,
1853           _IIter2 __end2, _OutputIterator __result,
1854           __gnu_parallel::sequential_tag)
1855     { return _GLIBCXX_STD_A::merge(
1856                __begin1, __end1, __begin2, __end2, __result); }
1857
1858   // Sequential fallback
1859   template<typename _IIter1, typename _IIter2,
1860            typename _OutputIterator, typename _Compare>
1861     inline _OutputIterator
1862     merge(_IIter1 __begin1, _IIter1 __end1, _IIter2 __begin2,
1863           _IIter2 __end2, _OutputIterator __result, _Compare __comp,
1864           __gnu_parallel::sequential_tag)
1865     { return _GLIBCXX_STD_A::merge(
1866                 __begin1, __end1, __begin2, __end2, __result, __comp); }
1867
1868   // Sequential fallback for input iterator case
1869   template<typename _IIter1, typename _IIter2, typename _OutputIterator,
1870            typename _Compare, typename _IteratorTag1,
1871            typename _IteratorTag2, typename _IteratorTag3>
1872     inline _OutputIterator
1873     __merge_switch(_IIter1 __begin1, _IIter1 __end1,
1874                    _IIter2 __begin2, _IIter2 __end2,
1875                    _OutputIterator __result, _Compare __comp,
1876                    _IteratorTag1, _IteratorTag2, _IteratorTag3)
1877      { return _GLIBCXX_STD_A::merge(__begin1, __end1, __begin2, __end2,
1878                                     __result, __comp); }
1879
1880   // Parallel algorithm for random access iterators
1881   template<typename _IIter1, typename _IIter2,
1882            typename _OutputIterator, typename _Compare>
1883     _OutputIterator
1884     __merge_switch(_IIter1 __begin1, _IIter1 __end1,
1885                    _IIter2 __begin2, _IIter2 __end2,
1886                    _OutputIterator __result, _Compare __comp,
1887                    random_access_iterator_tag, random_access_iterator_tag,
1888                    random_access_iterator_tag)
1889     {
1890       if (_GLIBCXX_PARALLEL_CONDITION(
1891             (static_cast<__gnu_parallel::_SequenceIndex>(__end1 - __begin1)
1892              >= __gnu_parallel::_Settings::get().merge_minimal_n
1893              || static_cast<__gnu_parallel::_SequenceIndex>(__end2 - __begin2)
1894              >= __gnu_parallel::_Settings::get().merge_minimal_n)))
1895         return __gnu_parallel::__parallel_merge_advance(
1896                  __begin1, __end1, __begin2, __end2, __result,
1897                  (__end1 - __begin1) + (__end2 - __begin2), __comp);
1898       else
1899         return __gnu_parallel::__merge_advance(
1900                  __begin1, __end1, __begin2, __end2, __result,
1901                  (__end1 - __begin1) + (__end2 - __begin2), __comp);
1902   }
1903
1904   // Public interface
1905   template<typename _IIter1, typename _IIter2,
1906            typename _OutputIterator, typename _Compare>
1907     inline _OutputIterator
1908     merge(_IIter1 __begin1, _IIter1 __end1, _IIter2 __begin2,
1909           _IIter2 __end2, _OutputIterator __result, _Compare __comp)
1910     {
1911       return __merge_switch(
1912                 __begin1, __end1, __begin2, __end2, __result, __comp,
1913                 std::__iterator_category(__begin1),
1914                 std::__iterator_category(__begin2),
1915                 std::__iterator_category(__result));
1916   }
1917
1918   // Public interface, insert default comparator
1919   template<typename _IIter1, typename _IIter2,
1920            typename _OutputIterator>
1921     inline _OutputIterator
1922     merge(_IIter1 __begin1, _IIter1 __end1, _IIter2 __begin2,
1923           _IIter2 __end2, _OutputIterator __result)
1924     {
1925       typedef typename std::iterator_traits<_IIter1>::value_type _ValueType1;
1926       typedef typename std::iterator_traits<_IIter2>::value_type _ValueType2;
1927
1928       return __gnu_parallel::merge(__begin1, __end1, __begin2, __end2,
1929                 __result, __gnu_parallel::_Less<_ValueType1, _ValueType2>());
1930     }
1931
1932   // Sequential fallback
1933   template<typename _RAIter>
1934     inline void
1935     nth_element(_RAIter __begin, _RAIter __nth,
1936                 _RAIter __end, __gnu_parallel::sequential_tag)
1937     { return _GLIBCXX_STD_A::nth_element(__begin, __nth, __end); }
1938
1939   // Sequential fallback
1940   template<typename _RAIter, typename _Compare>
1941     inline void
1942     nth_element(_RAIter __begin, _RAIter __nth,
1943                 _RAIter __end, _Compare __comp,
1944                 __gnu_parallel::sequential_tag)
1945     { return _GLIBCXX_STD_A::nth_element(__begin, __nth, __end, __comp); }
1946
1947   // Public interface
1948   template<typename _RAIter, typename _Compare>
1949     inline void
1950     nth_element(_RAIter __begin, _RAIter __nth,
1951                 _RAIter __end, _Compare __comp)
1952     {
1953       if (_GLIBCXX_PARALLEL_CONDITION(
1954             static_cast<__gnu_parallel::_SequenceIndex>(__end - __begin)
1955             >= __gnu_parallel::_Settings::get().nth_element_minimal_n))
1956         __gnu_parallel::__parallel_nth_element(__begin, __nth, __end, __comp);
1957       else
1958         nth_element(__begin, __nth, __end, __comp,
1959                     __gnu_parallel::sequential_tag());
1960     }
1961
1962   // Public interface, insert default comparator
1963   template<typename _RAIter>
1964     inline void
1965     nth_element(_RAIter __begin, _RAIter __nth,
1966                 _RAIter __end)
1967     {
1968       typedef typename iterator_traits<_RAIter>::value_type _ValueType;
1969       __gnu_parallel::nth_element(__begin, __nth, __end,
1970                                   std::less<_ValueType>());
1971     }
1972
1973   // Sequential fallback
1974   template<typename _RAIter, typename _Compare>
1975     inline void
1976     partial_sort(_RAIter __begin, _RAIter __middle,
1977                  _RAIter __end, _Compare __comp,
1978                  __gnu_parallel::sequential_tag)
1979     { _GLIBCXX_STD_A::partial_sort(__begin, __middle, __end, __comp); }
1980
1981   // Sequential fallback
1982   template<typename _RAIter>
1983     inline void
1984     partial_sort(_RAIter __begin, _RAIter __middle,
1985                  _RAIter __end, __gnu_parallel::sequential_tag)
1986     { _GLIBCXX_STD_A::partial_sort(__begin, __middle, __end); }
1987
1988   // Public interface, parallel algorithm for random access iterators
1989   template<typename _RAIter, typename _Compare>
1990     void
1991     partial_sort(_RAIter __begin, _RAIter __middle,
1992                  _RAIter __end, _Compare __comp)
1993     {
1994       if (_GLIBCXX_PARALLEL_CONDITION(
1995             static_cast<__gnu_parallel::_SequenceIndex>(__end - __begin)
1996             >= __gnu_parallel::_Settings::get().partial_sort_minimal_n))
1997         __gnu_parallel::
1998           __parallel_partial_sort(__begin, __middle, __end, __comp);
1999       else
2000         partial_sort(__begin, __middle, __end, __comp,
2001                      __gnu_parallel::sequential_tag());
2002     }
2003
2004   // Public interface, insert default comparator
2005   template<typename _RAIter>
2006     inline void
2007     partial_sort(_RAIter __begin, _RAIter __middle,
2008                  _RAIter __end)
2009     {
2010       typedef iterator_traits<_RAIter> _TraitsType;
2011       typedef typename _TraitsType::value_type _ValueType;
2012       __gnu_parallel::partial_sort(__begin, __middle, __end,
2013                                    std::less<_ValueType>());
2014     }
2015
2016   // Sequential fallback
2017   template<typename _FIterator>
2018     inline _FIterator
2019     max_element(_FIterator __begin, _FIterator __end,
2020                 __gnu_parallel::sequential_tag)
2021     { return _GLIBCXX_STD_A::max_element(__begin, __end); }
2022
2023   // Sequential fallback
2024   template<typename _FIterator, typename _Compare>
2025     inline _FIterator
2026     max_element(_FIterator __begin, _FIterator __end, _Compare __comp,
2027                 __gnu_parallel::sequential_tag)
2028     { return _GLIBCXX_STD_A::max_element(__begin, __end, __comp); }
2029
2030   // Sequential fallback for input iterator case
2031   template<typename _FIterator, typename _Compare, typename _IteratorTag>
2032     inline _FIterator
2033     __max_element_switch(_FIterator __begin, _FIterator __end,
2034                        _Compare __comp, _IteratorTag)
2035     { return max_element(__begin, __end, __comp,
2036                          __gnu_parallel::sequential_tag()); }
2037
2038   // Parallel algorithm for random access iterators
2039   template<typename _RAIter, typename _Compare>
2040     _RAIter
2041     __max_element_switch(_RAIter __begin, _RAIter __end,
2042                          _Compare __comp, random_access_iterator_tag,
2043                          __gnu_parallel::_Parallelism __parallelism_tag)
2044     {
2045       if (_GLIBCXX_PARALLEL_CONDITION(
2046             static_cast<__gnu_parallel::_SequenceIndex>(__end - __begin)
2047             >= __gnu_parallel::_Settings::get().max_element_minimal_n
2048             && __gnu_parallel::__is_parallel(__parallelism_tag)))
2049         {
2050           _RAIter __res(__begin);
2051           __gnu_parallel::__identity_selector<_RAIter>
2052             __functionality;
2053           __gnu_parallel::
2054             __for_each_template_random_access(
2055               __begin, __end, __gnu_parallel::_Nothing(), __functionality,
2056               __gnu_parallel::__max_element_reduct<_Compare, _RAIter>(__comp),
2057               __res, __res, -1, __parallelism_tag);
2058           return __res;
2059         }
2060       else
2061         return max_element(__begin, __end, __comp,
2062                            __gnu_parallel::sequential_tag());
2063     }
2064
2065   // Public interface, insert default comparator
2066   template<typename _FIterator>
2067     inline _FIterator
2068     max_element(_FIterator __begin, _FIterator __end,
2069                 __gnu_parallel::_Parallelism __parallelism_tag)
2070     {
2071       typedef typename iterator_traits<_FIterator>::value_type _ValueType;
2072       return max_element(__begin, __end, std::less<_ValueType>(),
2073                          __parallelism_tag);
2074     }
2075
2076   template<typename _FIterator>
2077     inline _FIterator
2078     max_element(_FIterator __begin, _FIterator __end)
2079     {
2080       typedef typename iterator_traits<_FIterator>::value_type _ValueType;
2081       return __gnu_parallel::max_element(__begin, __end,
2082                                          std::less<_ValueType>());
2083     }
2084
2085   // Public interface
2086   template<typename _FIterator, typename _Compare>
2087     inline _FIterator
2088     max_element(_FIterator __begin, _FIterator __end, _Compare __comp,
2089                 __gnu_parallel::_Parallelism __parallelism_tag)
2090     {
2091       return __max_element_switch(__begin, __end, __comp,
2092                                   std::__iterator_category(__begin),
2093                                   __parallelism_tag);
2094     }
2095
2096   template<typename _FIterator, typename _Compare>
2097     inline _FIterator
2098     max_element(_FIterator __begin, _FIterator __end, _Compare __comp)
2099     {
2100       return __max_element_switch(__begin, __end, __comp,
2101                                   std::__iterator_category(__begin));
2102     }
2103
2104
2105   // Sequential fallback
2106   template<typename _FIterator>
2107     inline _FIterator
2108     min_element(_FIterator __begin, _FIterator __end,
2109                 __gnu_parallel::sequential_tag)
2110     { return _GLIBCXX_STD_A::min_element(__begin, __end); }
2111
2112   // Sequential fallback
2113   template<typename _FIterator, typename _Compare>
2114     inline _FIterator
2115     min_element(_FIterator __begin, _FIterator __end, _Compare __comp,
2116                 __gnu_parallel::sequential_tag)
2117     { return _GLIBCXX_STD_A::min_element(__begin, __end, __comp); }
2118
2119   // Sequential fallback for input iterator case
2120   template<typename _FIterator, typename _Compare, typename _IteratorTag>
2121     inline _FIterator
2122     __min_element_switch(_FIterator __begin, _FIterator __end,
2123                        _Compare __comp, _IteratorTag)
2124     { return min_element(__begin, __end, __comp,
2125                          __gnu_parallel::sequential_tag()); }
2126
2127   // Parallel algorithm for random access iterators
2128   template<typename _RAIter, typename _Compare>
2129     _RAIter
2130     __min_element_switch(_RAIter __begin, _RAIter __end,
2131                          _Compare __comp, random_access_iterator_tag,
2132                          __gnu_parallel::_Parallelism __parallelism_tag)
2133     {
2134       if (_GLIBCXX_PARALLEL_CONDITION(
2135             static_cast<__gnu_parallel::_SequenceIndex>(__end - __begin)
2136             >= __gnu_parallel::_Settings::get().min_element_minimal_n
2137             && __gnu_parallel::__is_parallel(__parallelism_tag)))
2138         {
2139           _RAIter __res(__begin);
2140           __gnu_parallel::__identity_selector<_RAIter>
2141             __functionality;
2142           __gnu_parallel::
2143             __for_each_template_random_access(
2144               __begin, __end, __gnu_parallel::_Nothing(), __functionality,
2145               __gnu_parallel::__min_element_reduct<_Compare, _RAIter>(__comp),
2146               __res, __res, -1, __parallelism_tag);
2147           return __res;
2148         }
2149       else
2150         return min_element(__begin, __end, __comp,
2151                            __gnu_parallel::sequential_tag());
2152     }
2153
2154   // Public interface, insert default comparator
2155   template<typename _FIterator>
2156     inline _FIterator
2157     min_element(_FIterator __begin, _FIterator __end,
2158                 __gnu_parallel::_Parallelism __parallelism_tag)
2159     {
2160       typedef typename iterator_traits<_FIterator>::value_type _ValueType;
2161       return min_element(__begin, __end, std::less<_ValueType>(),
2162                          __parallelism_tag);
2163     }
2164
2165   template<typename _FIterator>
2166     inline _FIterator
2167     min_element(_FIterator __begin, _FIterator __end)
2168     {
2169       typedef typename iterator_traits<_FIterator>::value_type _ValueType;
2170       return __gnu_parallel::min_element(__begin, __end,
2171                                          std::less<_ValueType>());
2172     }
2173
2174   // Public interface
2175   template<typename _FIterator, typename _Compare>
2176     inline _FIterator
2177     min_element(_FIterator __begin, _FIterator __end, _Compare __comp,
2178                 __gnu_parallel::_Parallelism __parallelism_tag)
2179     {
2180       return __min_element_switch(__begin, __end, __comp,
2181                                   std::__iterator_category(__begin),
2182                                   __parallelism_tag);
2183     }
2184
2185   template<typename _FIterator, typename _Compare>
2186     inline _FIterator
2187     min_element(_FIterator __begin, _FIterator __end, _Compare __comp)
2188     {
2189       return __min_element_switch(__begin, __end, __comp,
2190                                   std::__iterator_category(__begin));
2191     }
2192 } // end namespace
2193 } // end namespace
2194
2195 #endif /* _GLIBCXX_PARALLEL_ALGO_H */