text: //===----------------------------------------------------------------------===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is dual licensed under the MIT and the University of Illinois Open
  // Source Licenses. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  
  // <algorithm>
  
  // template<ForwardIterator Iter1, ForwardIterator Iter2>
  //   requires HasEqualTo<Iter1::value_type, Iter2::value_type>
  //   constexpr Iter1     // constexpr after C++17
  //   search(Iter1 first1, Iter1 last1, Iter2 first2, Iter2 last2);
  //
  //   template<class ForwardIterator, class Searcher>
  //   ForwardIterator search(ForwardIterator first, ForwardIterator last,
  //                          const Searcher& searcher); // C++17
  
  #include <algorithm>
  #include <cassert>
  
  #include "test_macros.h"
  #include "test_iterators.h"
  
  struct MySearcherC {
      template <typename Iterator>
      std::pair<Iterator, Iterator>
      TEST_CONSTEXPR operator() (Iterator b, Iterator e) const
      {
          return std::make_pair(b, e);
      }
  };
  
  #if TEST_STD_VER > 17
  TEST_CONSTEXPR bool test_constexpr() {
      int ia[] = {0, 1, 2, 3};
      int ib[] = {0, 1, 5, 3};
      int ic[] = {0, 1, 2, 0, 1, 2, 3, 0, 1, 2, 3, 4};
      return    (std::search(std::begin(ic), std::end(ic), std::begin(ia), std::end(ia)) == ic+3)
             && (std::search(std::begin(ic), std::end(ic), std::begin(ib), std::end(ib)) == std::end(ic))
             && (std::search(std::begin(ic), std::end(ic), MySearcherC()) == std::begin(ic))
             ;
      }
  #endif
  
  int searcher_called = 0;
  
  struct MySearcher {
      template <typename Iterator>
      std::pair<Iterator, Iterator>
      operator() (Iterator b, Iterator e) const
      {
          ++searcher_called;
          return std::make_pair(b, e);
      }
  };
  
  template <class Iter1, class Iter2>
  void
  test()
  {
      int ia[] = {0, 1, 2, 3, 4, 5};
      const unsigned sa = sizeof(ia)/sizeof(ia[0]);
      assert(std::search(Iter1(ia), Iter1(ia+sa), Iter2(ia), Iter2(ia)) == Iter1(ia));
      assert(std::search(Iter1(ia), Iter1(ia+sa), Iter2(ia), Iter2(ia+1)) == Iter1(ia));
      assert(std::search(Iter1(ia), Iter1(ia+sa), Iter2(ia+1), Iter2(ia+2)) == Iter1(ia+1));
      assert(std::search(Iter1(ia), Iter1(ia+sa), Iter2(ia+2), Iter2(ia+2)) == Iter1(ia));
      assert(std::search(Iter1(ia), Iter1(ia+sa), Iter2(ia+2), Iter2(ia+3)) == Iter1(ia+2));
      assert(std::search(Iter1(ia), Iter1(ia+sa), Iter2(ia+2), Iter2(ia+3)) == Iter1(ia+2));
      assert(std::search(Iter1(ia), Iter1(ia), Iter2(ia+2), Iter2(ia+3)) == Iter1(ia));
      assert(std::search(Iter1(ia), Iter1(ia+sa), Iter2(ia+sa-1), Iter2(ia+sa)) == Iter1(ia+sa-1));
      assert(std::search(Iter1(ia), Iter1(ia+sa), Iter2(ia+sa-3), Iter2(ia+sa)) == Iter1(ia+sa-3));
      assert(std::search(Iter1(ia), Iter1(ia+sa), Iter2(ia), Iter2(ia+sa)) == Iter1(ia));
      assert(std::search(Iter1(ia), Iter1(ia+sa-1), Iter2(ia), Iter2(ia+sa)) == Iter1(ia+sa-1));
      assert(std::search(Iter1(ia), Iter1(ia+1), Iter2(ia), Iter2(ia+sa)) == Iter1(ia+1));
      int ib[] = {0, 1, 2, 0, 1, 2, 3, 0, 1, 2, 3, 4};
      const unsigned sb = sizeof(ib)/sizeof(ib[0]);
      int ic[] = {1};
      assert(std::search(Iter1(ib), Iter1(ib+sb), Iter2(ic), Iter2(ic+1)) == Iter1(ib+1));
      int id[] = {1, 2};
      assert(std::search(Iter1(ib), Iter1(ib+sb), Iter2(id), Iter2(id+2)) == Iter1(ib+1));
      int ie[] = {1, 2, 3};
      assert(std::search(Iter1(ib), Iter1(ib+sb), Iter2(ie), Iter2(ie+3)) == Iter1(ib+4));
      int ig[] = {1, 2, 3, 4};
      assert(std::search(Iter1(ib), Iter1(ib+sb), Iter2(ig), Iter2(ig+4)) == Iter1(ib+8));
      int ih[] = {0, 1, 1, 1, 1, 2, 3, 0, 1, 2, 3, 4};
      const unsigned sh = sizeof(ih)/sizeof(ih[0]);
      int ii[] = {1, 1, 2};
      assert(std::search(Iter1(ih), Iter1(ih+sh), Iter2(ii), Iter2(ii+3)) == Iter1(ih+3));
      int ij[] = {0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0};
      const unsigned sj = sizeof(ij)/sizeof(ij[0]);
      int ik[] = {0, 0, 0, 0, 1, 1, 1, 1, 0, 0};
      const unsigned sk = sizeof(ik)/sizeof(ik[0]);
      assert(std::search(Iter1(ij), Iter1(ij+sj), Iter2(ik), Iter2(ik+sk)) == Iter1(ij+6));
  }
  
  int main()
  {
      test<forward_iterator<const int*>, forward_iterator<const int*> >();
      test<forward_iterator<const int*>, bidirectional_iterator<const int*> >();
      test<forward_iterator<const int*>, random_access_iterator<const int*> >();
      test<bidirectional_iterator<const int*>, forward_iterator<const int*> >();
      test<bidirectional_iterator<const int*>, bidirectional_iterator<const int*> >();
      test<bidirectional_iterator<const int*>, random_access_iterator<const int*> >();
      test<random_access_iterator<const int*>, forward_iterator<const int*> >();
      test<random_access_iterator<const int*>, bidirectional_iterator<const int*> >();
      test<random_access_iterator<const int*>, random_access_iterator<const int*> >();
  
  #if TEST_STD_VER > 14
  {
      typedef int * RI;
      static_assert((std::is_same<RI, decltype(std::search(RI(), RI(), MySearcher()))>::value), "" );
  
      RI it(nullptr);
      assert(it == std::search(it, it, MySearcher()));
      assert(searcher_called == 1);
  }
  #endif
  
  #if TEST_STD_VER > 17
      static_assert(test_constexpr());
  #endif
  }
  