libcxx/test/std/algorithms/alg.nonmodifying/alg.adjacent.find/ranges.adjacent_find.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 // UNSUPPORTED: c++03, c++11, c++14, c++17
  12
  13 // template<forward_iterator I, sentinel_for<I> S, class Proj = identity,
  14 //          indirect_binary_predicate<projected<I, Proj>,
  15 //                                    projected<I, Proj>> Pred = ranges::equal_to>
  16 //   constexpr I ranges::adjacent_find(I first, S last, Pred pred = {}, Proj proj = {});
  17 // template<forward_range R, class Proj = identity,
  18 //          indirect_binary_predicate<projected<iterator_t<R>, Proj>,
  19 //                                    projected<iterator_t<R>, Proj>> Pred = ranges::equal_to>
  20 //   constexpr borrowed_iterator_t<R> ranges::adjacent_find(R&& r, Pred pred = {}, Proj proj = {});
  21
  22 #include <algorithm>
  23 #include <array>
  24 #include <cassert>
  25 #include <cstddef>
  26 #include <ranges>
  27
  28 #include "almost_satisfies_types.h"
  29 #include "test_iterators.h"
  30
  31 template <class Iter, class Sent = Iter>
  32 concept HasAdjacentFindIt = requires (Iter iter, Sent sent) { std::ranges::adjacent_find(iter, sent); };
  33
  34 struct NotComparable {};
  35
  36 static_assert(HasAdjacentFindIt<int*>);
  37 static_assert(!HasAdjacentFindIt<ForwardIteratorNotDerivedFrom>);
  38 static_assert(!HasAdjacentFindIt<ForwardIteratorNotIncrementable>);
  39 static_assert(!HasAdjacentFindIt<int*, SentinelForNotSemiregular>);
  40 static_assert(!HasAdjacentFindIt<int*, SentinelForNotWeaklyEqualityComparableWith>);
  41 static_assert(!HasAdjacentFindIt<NotComparable*>);
  42
  43 template <class Range>
  44 concept HasAdjacentFindR = requires (Range range) { std::ranges::adjacent_find(range); };
  45
  46 static_assert(HasAdjacentFindR<UncheckedRange<int*>>);
  47 static_assert(!HasAdjacentFindR<ForwardRangeNotDerivedFrom>);
  48 static_assert(!HasAdjacentFindR<ForwardRangeNotIncrementable>);
  49 static_assert(!HasAdjacentFindR<ForwardRangeNotSentinelSemiregular>);
  50 static_assert(!HasAdjacentFindR<ForwardRangeNotSentinelEqualityComparableWith>);
  51 static_assert(!HasAdjacentFindR<UncheckedRange<NotComparable>>);
  52
  53 template <std::size_t N>
  54 struct Data {
  55   std::array<int, N> input;
  56   int expected;
  57 };
  58
  59 template <class Iter, class Sent, std::size_t N>
  60 constexpr void test(Data<N> d) {
  61   {
  62     std::same_as<Iter> decltype(auto) ret =
  63         std::ranges::adjacent_find(Iter(d.input.data()), Sent(Iter(d.input.data() + d.input.size())));
  64     assert(base(ret) == d.input.data() + d.expected);
  65   }
  66   {
  67     auto range = std::ranges::subrange(Iter(d.input.data()), Sent(Iter(d.input.data() + d.input.size())));
  68     std::same_as<Iter> decltype(auto) ret = std::ranges::adjacent_find(range);
  69     assert(base(ret) == d.input.data() + d.expected);
  70   }
  71 }
  72
  73 template <class Iter, class Sent = Iter>
  74 constexpr void test_iterators() {
  75   // simple test
  76   test<Iter, Sent, 4>({.input = {1, 2, 2, 4}, .expected = 1});
  77   // last is returned with no match
  78   test<Iter, Sent, 4>({.input = {1, 2, 3, 4}, .expected = 4});
  79   // first elements match
  80   test<Iter, Sent, 4>({.input = {1, 1, 3, 4}, .expected = 0});
  81   // the first match is returned
  82   test<Iter, Sent, 7>({.input = {1, 1, 3, 4, 4, 4, 4}, .expected = 0});
  83   // two element range works
  84   test<Iter, Sent, 2>({.input = {3, 3}, .expected = 0});
  85   // single element range works
  86   test<Iter, Sent, 1>({.input = {1}, .expected = 1});
  87   // empty range works
  88   test<Iter, Sent, 0>({.input = {}, .expected = 0});
  89 }
  90
  91 constexpr bool test() {
  92   test_iterators<forward_iterator<int*>, sentinel_wrapper<forward_iterator<int*>>>();
  93   test_iterators<forward_iterator<int*>>();
  94   test_iterators<bidirectional_iterator<int*>>();
  95   test_iterators<random_access_iterator<int*>>();
  96   test_iterators<contiguous_iterator<int*>>();
  97   test_iterators<int*>();
  98   test_iterators<const int*>();
  99
 100   { // check that ranges::dangling is returned
 101     [[maybe_unused]] std::same_as<std::ranges::dangling> decltype(auto) ret =
 102         std::ranges::adjacent_find(std::array{1, 2, 3, 4});
 103   }
 104
 105   { // check that the complexity requirements are met with no match
 106     {
 107       int predicateCount = 0;
 108       auto pred = [&](int, int) { ++predicateCount; return false; };
 109       auto projectionCount = 0;
 110       auto proj = [&](int i) { ++projectionCount; return i; };
 111       int a[] = {1, 2, 3, 4, 5};
 112       auto ret = std::ranges::adjacent_find(a, a + 5, pred, proj);
 113       assert(ret == a + 5);
 114       assert(predicateCount == 4);
 115       assert(projectionCount == 8);
 116     }
 117     {
 118       int predicateCount = 0;
 119       auto pred = [&](int, int) { ++predicateCount; return false; };
 120       auto projectionCount = 0;
 121       auto proj = [&](int i) { ++projectionCount; return i; };
 122       int a[] = {1, 2, 3, 4, 5};
 123       auto ret = std::ranges::adjacent_find(a, pred, proj);
 124       assert(ret == a + 5);
 125       assert(predicateCount == 4);
 126       assert(projectionCount == 8);
 127     }
 128   }
 129
 130   { // check that the complexity requirements are met with a match
 131     {
 132       int predicateCount = 0;
 133       auto pred = [&](int i, int j) { ++predicateCount; return i == j; };
 134       auto projectionCount = 0;
 135       auto proj = [&](int i) { ++projectionCount; return i; };
 136       int a[] = {1, 2, 4, 4, 5};
 137       auto ret = std::ranges::adjacent_find(a, a + 5, pred, proj);
 138       assert(ret == a + 2);
 139       assert(predicateCount == 3);
 140       assert(projectionCount == 6);
 141     }
 142     {
 143       int predicateCount = 0;
 144       auto pred = [&](int i, int j) { ++predicateCount; return i == j; };
 145       auto projectionCount = 0;
 146       auto proj = [&](int i) { ++projectionCount; return i; };
 147       int a[] = {1, 2, 4, 4, 5};
 148       auto ret = std::ranges::adjacent_find(a, pred, proj);
 149       assert(ret == a + 2);
 150       assert(predicateCount == 3);
 151       assert(projectionCount == 6);
 152     }
 153   }
 154
 155   { // check that std::invoke is used
 156     struct S {
 157       constexpr S(int i_) : i(i_) {}
 158       constexpr bool compare(const S& j) const { return j.i == i; }
 159       constexpr const S& identity() const { return *this; }
 160       int i;
 161     };
 162     {
 163       S a[] = {1, 2, 3, 4};
 164       auto ret = std::ranges::adjacent_find(std::begin(a), std::end(a), &S::compare, &S::identity);
 165       assert(ret == a + 4);
 166     }
 167     {
 168       S a[] = {1, 2, 3, 4};
 169       auto ret = std::ranges::adjacent_find(a, &S::compare, &S::identity);
 170       assert(ret == a + 4);
 171     }
 172   }
 173
 174   return true;
 175 }
 176
 177 int main(int, char**) {
 178   test();
 179   static_assert(test());
 180
 181   return 0;
 182 }