libcxx/test/std/algorithms/alg.nonmodifying/alg.find.end/find_end_pred.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // <algorithm>
  10
  11 // template<ForwardIterator Iter1, ForwardIterator Iter2,
  12 //          Predicate<auto, Iter1::value_type, Iter2::value_type> Pred>
  13 //   requires CopyConstructible<Pred>
  14 //   constexpr Iter1  // constexpr after C++17
  15 //   find_end(Iter1 first1, Iter1 last1, Iter2 first2, Iter2 last2, Pred pred);
  16
  17 #include <algorithm>
  18 #include <functional>
  19 #include <cassert>
  20
  21 #include "test_macros.h"
  22 #include "test_iterators.h"
  23
  24 struct count_equal
  25 {
  26     static unsigned count;
  27     template <class T>
  28     TEST_CONSTEXPR_CXX14 bool operator()(const T& x, const T& y)
  29         {++count; return x == y;}
  30 };
  31
  32 #if TEST_STD_VER > 17
  33 constexpr bool test_constexpr() {
  34     int ia[] = {0, 1, 2};
  35     int ib[] = {4, 5, 6};
  36     int ic[] = {0, 1, 2, 3, 4, 5, 0, 1, 2, 3, 4, 0, 1, 2, 3, 0, 1, 2, 0, 1, 0};
  37     typedef forward_iterator<int*>       FI;
  38     typedef bidirectional_iterator<int*> BI;
  39     typedef random_access_iterator<int*> RI;
  40     std::equal_to<int> eq{};
  41     return    (std::find_end(FI(std::begin(ic)), FI(std::end(ic)), FI(std::begin(ia)), FI(std::end(ia)), eq) == FI(ic+15))
  42            && (std::find_end(FI(std::begin(ic)), FI(std::end(ic)), FI(std::begin(ib)), FI(std::end(ib)), eq) == FI(std::end(ic)))
  43            && (std::find_end(BI(std::begin(ic)), BI(std::end(ic)), BI(std::begin(ia)), BI(std::end(ia)), eq) == BI(ic+15))
  44            && (std::find_end(BI(std::begin(ic)), BI(std::end(ic)), BI(std::begin(ib)), BI(std::end(ib)), eq) == BI(std::end(ic)))
  45            && (std::find_end(RI(std::begin(ic)), RI(std::end(ic)), RI(std::begin(ia)), RI(std::end(ia)), eq) == RI(ic+15))
  46            && (std::find_end(RI(std::begin(ic)), RI(std::end(ic)), RI(std::begin(ib)), RI(std::end(ib)), eq) == RI(std::end(ic)))
  47            ;
  48     }
  49 #endif
  50
  51 unsigned count_equal::count = 0;
  52
  53 template <class Iter1, class Iter2>
  54 void
  55 test()
  56 {
  57     int ia[] = {0, 1, 2, 3, 4, 5, 0, 1, 2, 3, 4, 0, 1, 2, 3, 0, 1, 2, 0, 1, 0};
  58     const unsigned sa = sizeof(ia)/sizeof(ia[0]);
  59     int b[] = {0};
  60     count_equal::count = 0;
  61     assert(std::find_end(Iter1(ia), Iter1(ia+sa), Iter2(b), Iter2(b+1), count_equal()) == Iter1(ia+sa-1));
  62     assert(count_equal::count <= 1*(sa-1+1));
  63     int c[] = {0, 1};
  64     count_equal::count = 0;
  65     assert(std::find_end(Iter1(ia), Iter1(ia+sa), Iter2(c), Iter2(c+2), count_equal()) == Iter1(ia+18));
  66     assert(count_equal::count <= 2*(sa-2+1));
  67     int d[] = {0, 1, 2};
  68     count_equal::count = 0;
  69     assert(std::find_end(Iter1(ia), Iter1(ia+sa), Iter2(d), Iter2(d+3), count_equal()) == Iter1(ia+15));
  70     assert(count_equal::count <= 3*(sa-3+1));
  71     int e[] = {0, 1, 2, 3};
  72     count_equal::count = 0;
  73     assert(std::find_end(Iter1(ia), Iter1(ia+sa), Iter2(e), Iter2(e+4), count_equal()) == Iter1(ia+11));
  74     assert(count_equal::count <= 4*(sa-4+1));
  75     int f[] = {0, 1, 2, 3, 4};
  76     count_equal::count = 0;
  77     assert(std::find_end(Iter1(ia), Iter1(ia+sa), Iter2(f), Iter2(f+5), count_equal()) == Iter1(ia+6));
  78     assert(count_equal::count <= 5*(sa-5+1));
  79     int g[] = {0, 1, 2, 3, 4, 5};
  80     count_equal::count = 0;
  81     assert(std::find_end(Iter1(ia), Iter1(ia+sa), Iter2(g), Iter2(g+6), count_equal()) == Iter1(ia));
  82     assert(count_equal::count <= 6*(sa-6+1));
  83     int h[] = {0, 1, 2, 3, 4, 5, 6};
  84     count_equal::count = 0;
  85     assert(std::find_end(Iter1(ia), Iter1(ia+sa), Iter2(h), Iter2(h+7), count_equal()) == Iter1(ia+sa));
  86     assert(count_equal::count <= 7*(sa-7+1));
  87     count_equal::count = 0;
  88     assert(std::find_end(Iter1(ia), Iter1(ia+sa), Iter2(b), Iter2(b), count_equal()) == Iter1(ia+sa));
  89     assert(count_equal::count <= 0);
  90     count_equal::count = 0;
  91     assert(std::find_end(Iter1(ia), Iter1(ia), Iter2(b), Iter2(b+1), count_equal()) == Iter1(ia));
  92     assert(count_equal::count <= 0);
  93 }
  94
  95 int main(int, char**)
  96 {
  97     test<forward_iterator<const int*>, forward_iterator<const int*> >();
  98     test<forward_iterator<const int*>, bidirectional_iterator<const int*> >();
  99     test<forward_iterator<const int*>, random_access_iterator<const int*> >();
 100     test<bidirectional_iterator<const int*>, forward_iterator<const int*> >();
 101     test<bidirectional_iterator<const int*>, bidirectional_iterator<const int*> >();
 102     test<bidirectional_iterator<const int*>, random_access_iterator<const int*> >();
 103     test<random_access_iterator<const int*>, forward_iterator<const int*> >();
 104     test<random_access_iterator<const int*>, bidirectional_iterator<const int*> >();
 105     test<random_access_iterator<const int*>, random_access_iterator<const int*> >();
 106
 107 #if TEST_STD_VER > 17
 108     static_assert(test_constexpr());
 109 #endif
 110
 111   return 0;
 112 }