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      1 //===----------------------------------------------------------------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is dual licensed under the MIT and the University of Illinois Open
      6 // Source Licenses. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 
     10 // <algorithm>
     11 
     12 // template<ForwardIterator Iter1, ForwardIterator Iter2,
     13 //          Predicate<auto, Iter1::value_type, Iter2::value_type> Pred>
     14 //   requires CopyConstructible<Pred>
     15 //   constexpr Iter1  // constexpr after C++17
     16 //   find_end(Iter1 first1, Iter1 last1, Iter2 first2, Iter2 last2, Pred pred);
     17 
     18 #include <algorithm>
     19 #include <functional>
     20 #include <cassert>
     21 
     22 #include "test_macros.h"
     23 #include "test_iterators.h"
     24 
     25 struct count_equal
     26 {
     27     static unsigned count;
     28     template <class T>
     29     TEST_CONSTEXPR_CXX14 bool operator()(const T& x, const T& y)
     30         {++count; return x == y;}
     31 };
     32 
     33 #if TEST_STD_VER > 17
     34 constexpr bool test_constexpr() {
     35     int ia[] = {0, 1, 2};
     36     int ib[] = {4, 5, 6};
     37     int ic[] = {0, 1, 2, 3, 4, 5, 0, 1, 2, 3, 4, 0, 1, 2, 3, 0, 1, 2, 0, 1, 0};
     38     typedef forward_iterator<int*>       FI;
     39     typedef bidirectional_iterator<int*> BI;
     40     typedef random_access_iterator<int*> RI;
     41     std::equal_to<int> eq{};
     42     return    (std::find_end(FI(std::begin(ic)), FI(std::end(ic)), FI(std::begin(ia)), FI(std::end(ia)), eq) == FI(ic+15))
     43            && (std::find_end(FI(std::begin(ic)), FI(std::end(ic)), FI(std::begin(ib)), FI(std::end(ib)), eq) == FI(std::end(ic)))
     44            && (std::find_end(BI(std::begin(ic)), BI(std::end(ic)), BI(std::begin(ia)), BI(std::end(ia)), eq) == BI(ic+15))
     45            && (std::find_end(BI(std::begin(ic)), BI(std::end(ic)), BI(std::begin(ib)), BI(std::end(ib)), eq) == BI(std::end(ic)))
     46            && (std::find_end(RI(std::begin(ic)), RI(std::end(ic)), RI(std::begin(ia)), RI(std::end(ia)), eq) == RI(ic+15))
     47            && (std::find_end(RI(std::begin(ic)), RI(std::end(ic)), RI(std::begin(ib)), RI(std::end(ib)), eq) == RI(std::end(ic)))
     48            ;
     49     }
     50 #endif
     51 
     52 unsigned count_equal::count = 0;
     53 
     54 template <class Iter1, class Iter2>
     55 void
     56 test()
     57 {
     58     int ia[] = {0, 1, 2, 3, 4, 5, 0, 1, 2, 3, 4, 0, 1, 2, 3, 0, 1, 2, 0, 1, 0};
     59     const unsigned sa = sizeof(ia)/sizeof(ia[0]);
     60     int b[] = {0};
     61     count_equal::count = 0;
     62     assert(std::find_end(Iter1(ia), Iter1(ia+sa), Iter2(b), Iter2(b+1), count_equal()) == Iter1(ia+sa-1));
     63     assert(count_equal::count <= 1*(sa-1+1));
     64     int c[] = {0, 1};
     65     count_equal::count = 0;
     66     assert(std::find_end(Iter1(ia), Iter1(ia+sa), Iter2(c), Iter2(c+2), count_equal()) == Iter1(ia+18));
     67     assert(count_equal::count <= 2*(sa-2+1));
     68     int d[] = {0, 1, 2};
     69     count_equal::count = 0;
     70     assert(std::find_end(Iter1(ia), Iter1(ia+sa), Iter2(d), Iter2(d+3), count_equal()) == Iter1(ia+15));
     71     assert(count_equal::count <= 3*(sa-3+1));
     72     int e[] = {0, 1, 2, 3};
     73     count_equal::count = 0;
     74     assert(std::find_end(Iter1(ia), Iter1(ia+sa), Iter2(e), Iter2(e+4), count_equal()) == Iter1(ia+11));
     75     assert(count_equal::count <= 4*(sa-4+1));
     76     int f[] = {0, 1, 2, 3, 4};
     77     count_equal::count = 0;
     78     assert(std::find_end(Iter1(ia), Iter1(ia+sa), Iter2(f), Iter2(f+5), count_equal()) == Iter1(ia+6));
     79     assert(count_equal::count <= 5*(sa-5+1));
     80     int g[] = {0, 1, 2, 3, 4, 5};
     81     count_equal::count = 0;
     82     assert(std::find_end(Iter1(ia), Iter1(ia+sa), Iter2(g), Iter2(g+6), count_equal()) == Iter1(ia));
     83     assert(count_equal::count <= 6*(sa-6+1));
     84     int h[] = {0, 1, 2, 3, 4, 5, 6};
     85     count_equal::count = 0;
     86     assert(std::find_end(Iter1(ia), Iter1(ia+sa), Iter2(h), Iter2(h+7), count_equal()) == Iter1(ia+sa));
     87     assert(count_equal::count <= 7*(sa-7+1));
     88     count_equal::count = 0;
     89     assert(std::find_end(Iter1(ia), Iter1(ia+sa), Iter2(b), Iter2(b), count_equal()) == Iter1(ia+sa));
     90     assert(count_equal::count <= 0);
     91     count_equal::count = 0;
     92     assert(std::find_end(Iter1(ia), Iter1(ia), Iter2(b), Iter2(b+1), count_equal()) == Iter1(ia));
     93     assert(count_equal::count <= 0);
     94 }
     95 
     96 int main()
     97 {
     98     test<forward_iterator<const int*>, forward_iterator<const int*> >();
     99     test<forward_iterator<const int*>, bidirectional_iterator<const int*> >();
    100     test<forward_iterator<const int*>, random_access_iterator<const int*> >();
    101     test<bidirectional_iterator<const int*>, forward_iterator<const int*> >();
    102     test<bidirectional_iterator<const int*>, bidirectional_iterator<const int*> >();
    103     test<bidirectional_iterator<const int*>, random_access_iterator<const int*> >();
    104     test<random_access_iterator<const int*>, forward_iterator<const int*> >();
    105     test<random_access_iterator<const int*>, bidirectional_iterator<const int*> >();
    106     test<random_access_iterator<const int*>, random_access_iterator<const int*> >();
    107 
    108 #if TEST_STD_VER > 17
    109     static_assert(test_constexpr());
    110 #endif
    111 }
    112