| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // <algorithm> |
| |
| // UNSUPPORTED: c++03, c++11, c++14, c++17 |
| |
| // template<input_iterator I, sentinel_for<I> S, class T, class Proj = identity> |
| // requires indirect_binary_predicate<ranges::equal_to, projected<I, Proj>, const T*> |
| // constexpr iter_difference_t<I> |
| // ranges::count(I first, S last, const T& value, Proj proj = {}); |
| // template<input_range R, class T, class Proj = identity> |
| // requires indirect_binary_predicate<ranges::equal_to, projected<iterator_t<R>, Proj>, const T*> |
| // constexpr range_difference_t<R> |
| // ranges::count(R&& r, const T& value, Proj proj = {}); |
| |
| #include <algorithm> |
| #include <array> |
| #include <cassert> |
| #include <ranges> |
| |
| #include "almost_satisfies_types.h" |
| #include "test_iterators.h" |
| |
| struct NotEqualityComparable { |
| bool operator==(NotEqualityComparable&&) const; |
| bool operator==(NotEqualityComparable&) const; |
| bool operator==(const NotEqualityComparable&&) const; |
| }; |
| |
| template <class It, class Sent = It> |
| concept HasCountIt = requires(It it, Sent sent) { std::ranges::count(it, sent, *it); }; |
| static_assert(HasCountIt<int*>); |
| static_assert(!HasCountIt<NotEqualityComparable*>); |
| static_assert(!HasCountIt<InputIteratorNotDerivedFrom>); |
| static_assert(!HasCountIt<InputIteratorNotIndirectlyReadable>); |
| static_assert(!HasCountIt<InputIteratorNotInputOrOutputIterator>); |
| static_assert(!HasCountIt<cpp20_input_iterator<int*>, SentinelForNotSemiregular>); |
| static_assert(!HasCountIt<cpp20_input_iterator<int*>, InputRangeNotSentinelEqualityComparableWith>); |
| |
| static_assert(!HasCountIt<int*, int>); |
| static_assert(!HasCountIt<int, int*>); |
| |
| template <class Range, class ValT> |
| concept HasCountR = requires(Range r) { std::ranges::count(r, ValT{}); }; |
| static_assert(HasCountR<std::array<int, 1>, int>); |
| static_assert(!HasCountR<int, int>); |
| static_assert(!HasCountR<std::array<NotEqualityComparable, 1>, NotEqualityComparable>); |
| static_assert(!HasCountR<InputRangeNotDerivedFrom, int>); |
| static_assert(!HasCountR<InputRangeNotIndirectlyReadable, int>); |
| static_assert(!HasCountR<InputRangeNotInputOrOutputIterator, int>); |
| static_assert(!HasCountR<InputRangeNotSentinelSemiregular, int>); |
| static_assert(!HasCountR<InputRangeNotSentinelEqualityComparableWith, int>); |
| |
| template <class It, class Sent = It> |
| constexpr void test_iterators() { |
| { |
| // simple test |
| { |
| int a[] = {1, 2, 3, 4}; |
| std::same_as<std::ptrdiff_t> auto ret = std::ranges::count(It(a), Sent(It(a + 4)), 3); |
| assert(ret == 1); |
| } |
| { |
| int a[] = {1, 2, 3, 4}; |
| auto range = std::ranges::subrange(It(a), Sent(It(a + 4))); |
| std::same_as<std::ptrdiff_t> auto ret = std::ranges::count(range, 3); |
| assert(ret == 1); |
| } |
| } |
| |
| { |
| // check that an empty range works |
| { |
| std::array<int, 0> a = {}; |
| auto ret = std::ranges::count(It(a.data()), Sent(It(a.data() + a.size())), 1); |
| assert(ret == 0); |
| } |
| { |
| std::array<int, 0> a = {}; |
| auto range = std::ranges::subrange(It(a.data()), Sent(It(a.data() + a.size()))); |
| auto ret = std::ranges::count(range, 1); |
| assert(ret == 0); |
| } |
| } |
| |
| { |
| // check that a range with a single element works |
| { |
| std::array a = {2}; |
| auto ret = std::ranges::count(It(a.data()), Sent(It(a.data() + a.size())), 2); |
| assert(ret == 1); |
| } |
| { |
| std::array a = {2}; |
| auto range = std::ranges::subrange(It(a.data()), Sent(It(a.data() + a.size()))); |
| auto ret = std::ranges::count(range, 2); |
| assert(ret == 1); |
| } |
| } |
| |
| { |
| // check that 0 is returned with no match |
| { |
| std::array a = {1, 1, 1}; |
| auto ret = std::ranges::count(It(a.data()), Sent(It(a.data() + a.size())), 0); |
| assert(ret == 0); |
| } |
| { |
| std::array a = {1, 1, 1}; |
| auto range = std::ranges::subrange(It(a.data()), Sent(It(a.data() + a.size()))); |
| auto ret = std::ranges::count(range, 0); |
| assert(ret == 0); |
| } |
| } |
| |
| { |
| // check that more than one element is counted |
| { |
| std::array a = {3, 3, 4, 3, 3}; |
| auto ret = std::ranges::count(It(a.data()), Sent(It(a.data() + a.size())), 3); |
| assert(ret == 4); |
| } |
| { |
| std::array a = {3, 3, 4, 3, 3}; |
| auto range = std::ranges::subrange(It(a.data()), Sent(It(a.data() + a.size()))); |
| auto ret = std::ranges::count(range, 3); |
| assert(ret == 4); |
| } |
| } |
| |
| { |
| // check that all elements are counted |
| { |
| std::array a = {5, 5, 5, 5}; |
| auto ret = std::ranges::count(It(a.data()), Sent(It(a.data() + a.size())), 5); |
| assert(ret == 4); |
| } |
| { |
| std::array a = {5, 5, 5, 5}; |
| auto range = std::ranges::subrange(It(a.data()), Sent(It(a.data() + a.size()))); |
| auto ret = std::ranges::count(range, 5); |
| assert(ret == 4); |
| } |
| } |
| } |
| |
| constexpr bool test() { |
| test_iterators<int*>(); |
| test_iterators<const int*>(); |
| test_iterators<cpp20_input_iterator<int*>, sentinel_wrapper<cpp20_input_iterator<int*>>>(); |
| test_iterators<bidirectional_iterator<int*>>(); |
| test_iterators<forward_iterator<int*>>(); |
| test_iterators<random_access_iterator<int*>>(); |
| test_iterators<contiguous_iterator<int*>>(); |
| |
| { |
| // check that projections are used properly and that they are called with the iterator directly |
| { |
| int a[] = {1, 2, 3, 4}; |
| auto ret = std::ranges::count(a, a + 4, a + 3, [](int& i) { return &i; }); |
| assert(ret == 1); |
| } |
| { |
| int a[] = {1, 2, 3, 4}; |
| auto ret = std::ranges::count(a, a + 3, [](int& i) { return &i; }); |
| assert(ret == 1); |
| } |
| } |
| |
| { |
| // check that std::invoke is used |
| struct S { int i; }; |
| S a[] = { S{1}, S{3}, S{2} }; |
| std::same_as<std::ptrdiff_t> auto ret = std::ranges::count(a, 4, &S::i); |
| assert(ret == 0); |
| } |
| |
| { |
| // count invocations of the projection |
| { |
| int a[] = {1, 2, 3, 4}; |
| int projection_count = 0; |
| auto ret = std::ranges::count(a, a + 4, 2, [&](int i) { ++projection_count; return i; }); |
| assert(ret == 1); |
| assert(projection_count == 4); |
| } |
| { |
| int a[] = {1, 2, 3, 4}; |
| int projection_count = 0; |
| auto ret = std::ranges::count(a, 2, [&](int i) { ++projection_count; return i; }); |
| assert(ret == 1); |
| assert(projection_count == 4); |
| } |
| } |
| |
| { |
| // check that an immobile type works |
| struct NonMovable { |
| NonMovable(const NonMovable&) = delete; |
| NonMovable(NonMovable&&) = delete; |
| constexpr NonMovable(int i_) : i(i_) {} |
| int i; |
| |
| bool operator==(const NonMovable&) const = default; |
| }; |
| { |
| NonMovable a[] = {9, 8, 4, 3}; |
| auto ret = std::ranges::count(a, a + 4, NonMovable(8)); |
| assert(ret == 1); |
| } |
| { |
| NonMovable a[] = {9, 8, 4, 3}; |
| auto ret = std::ranges::count(a, NonMovable(8)); |
| assert(ret == 1); |
| } |
| } |
| |
| { |
| // check that difference_type is used |
| struct DiffTypeIterator { |
| using difference_type = signed char; |
| using value_type = int; |
| |
| int* it = nullptr; |
| |
| constexpr DiffTypeIterator() = default; |
| constexpr DiffTypeIterator(int* i) : it(i) {} |
| |
| constexpr int& operator*() const { return *it; } |
| constexpr DiffTypeIterator& operator++() { ++it; return *this; } |
| constexpr void operator++(int) { ++it; } |
| |
| bool operator==(const DiffTypeIterator&) const = default; |
| }; |
| |
| { |
| int a[] = {5, 5, 4, 3, 2, 1}; |
| std::same_as<signed char> decltype(auto) ret = |
| std::ranges::count(DiffTypeIterator(a), DiffTypeIterator(a + 6), 4); |
| assert(ret == 1); |
| } |
| { |
| int a[] = {5, 5, 4, 3, 2, 1}; |
| auto range = std::ranges::subrange(DiffTypeIterator(a), DiffTypeIterator(a + 6)); |
| std::same_as<signed char> decltype(auto) ret = std::ranges::count(range, 4); |
| assert(ret == 1); |
| } |
| } |
| |
| return true; |
| } |
| |
| int main(int, char**) { |
| test(); |
| static_assert(test()); |
| |
| return 0; |
| } |