| //===----------------------------------------------------------------------===// |
| // |
| // 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 Proj = identity, |
| // indirect_unary_predicate<projected<I, Proj>> Pred> |
| // constexpr I ranges::find_if(I first, S last, Pred pred, Proj proj = {}); |
| // template<input_range R, class Proj = identity, |
| // indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred> |
| // constexpr borrowed_iterator_t<R> |
| // ranges::find_if(R&& r, Pred pred, Proj proj = {}); |
| |
| #include <algorithm> |
| #include <array> |
| #include <cassert> |
| #include <ranges> |
| |
| #include "almost_satisfies_types.h" |
| #include "test_iterators.h" |
| |
| struct Predicate { |
| bool operator()(int); |
| }; |
| |
| template <class It, class Sent = It> |
| concept HasFindIfIt = requires(It it, Sent sent) { std::ranges::find_if(it, sent, Predicate{}); }; |
| static_assert(HasFindIfIt<int*>); |
| static_assert(!HasFindIfIt<InputIteratorNotDerivedFrom>); |
| static_assert(!HasFindIfIt<InputIteratorNotIndirectlyReadable>); |
| static_assert(!HasFindIfIt<InputIteratorNotInputOrOutputIterator>); |
| static_assert(!HasFindIfIt<cpp20_input_iterator<int*>, SentinelForNotSemiregular>); |
| static_assert(!HasFindIfIt<cpp20_input_iterator<int*>, InputRangeNotSentinelEqualityComparableWith>); |
| |
| static_assert(!HasFindIfIt<int*, int>); |
| static_assert(!HasFindIfIt<int, int*>); |
| |
| template <class Pred> |
| concept HasFindIfPred = requires(int* it, Pred pred) {std::ranges::find_if(it, it, pred); }; |
| |
| static_assert(!HasFindIfPred<IndirectUnaryPredicateNotCopyConstructible>); |
| static_assert(!HasFindIfPred<IndirectUnaryPredicateNotPredicate>); |
| |
| template <class R> |
| concept HasFindIfR = requires(R r) { std::ranges::find_if(r, Predicate{}); }; |
| static_assert(HasFindIfR<std::array<int, 0>>); |
| static_assert(!HasFindIfR<int>); |
| static_assert(!HasFindIfR<InputRangeNotDerivedFrom>); |
| static_assert(!HasFindIfR<InputRangeNotIndirectlyReadable>); |
| static_assert(!HasFindIfR<InputRangeNotInputOrOutputIterator>); |
| static_assert(!HasFindIfR<InputRangeNotSentinelSemiregular>); |
| static_assert(!HasFindIfR<InputRangeNotSentinelEqualityComparableWith>); |
| |
| template <class It, class Sent = It> |
| constexpr void test_iterators() { |
| { |
| int a[] = {1, 2, 3, 4}; |
| std::same_as<It> auto ret = std::ranges::find_if(It(a), Sent(It(a + 4)), [](int x) mutable { return x == 4; }); |
| assert(base(ret) == a + 3); |
| assert(*ret == 4); |
| } |
| { |
| int a[] = {1, 2, 3, 4}; |
| auto range = std::ranges::subrange(It(a), Sent(It(a + 4))); |
| std::same_as<It> auto ret = std::ranges::find_if(range, [](int x) mutable { return x == 4; }); |
| assert(base(ret) == a + 3); |
| assert(*ret == 4); |
| } |
| } |
| |
| struct NonConstComparable { |
| friend constexpr bool operator==(const NonConstComparable&, const NonConstComparable&) { return false; } |
| friend constexpr bool operator==(NonConstComparable&, NonConstComparable&) { return false; } |
| friend constexpr bool operator==(const NonConstComparable&, NonConstComparable&) { return false; } |
| friend constexpr bool operator==(NonConstComparable&, const NonConstComparable&) { return true; } |
| }; |
| |
| 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::find_if(a, a + 4, [&](int* i) { return i == a + 3; }, [](int& i) { return &i; }); |
| assert(ret == a + 3); |
| } |
| { |
| int a[] = {1, 2, 3, 4}; |
| auto ret = std::ranges::find_if(a, [&](int* i) { return i == a + 3; }, [](int& i) { return &i; }); |
| assert(ret == a + 3); |
| } |
| } |
| |
| { |
| // check that the first element is returned |
| { |
| struct S { |
| int comp; |
| int other; |
| }; |
| S a[] = { {0, 0}, {0, 2}, {0, 1} }; |
| auto ret = std::ranges::find_if(a, [](int i){ return i == 0; }, &S::comp); |
| assert(ret == a); |
| assert(ret->comp == 0); |
| assert(ret->other == 0); |
| } |
| { |
| struct S { |
| int comp; |
| int other; |
| }; |
| S a[] = { {0, 0}, {0, 2}, {0, 1} }; |
| auto ret = std::ranges::find_if(a, a + 3, [](int i) { return i == 0; }, &S::comp); |
| assert(ret == a); |
| assert(ret->comp == 0); |
| assert(ret->other == 0); |
| } |
| } |
| |
| { |
| // check that end + 1 iterator is returned with no match |
| { |
| int a[] = {1, 1, 1}; |
| auto ret = std::ranges::find_if(a, a + 3, [](int) { return false; }); |
| assert(ret == a + 3); |
| } |
| { |
| int a[] = {1, 1, 1}; |
| auto ret = std::ranges::find_if(a, [](int){ return false; }); |
| assert(ret == a + 3); |
| } |
| } |
| |
| { |
| // check that ranges::dangling is returned |
| [[maybe_unused]] std::same_as<std::ranges::dangling> auto ret = |
| std::ranges::find_if(std::array{1, 2}, [](int){ return false; }); |
| } |
| |
| { |
| // check that an iterator is returned with a borrowing range |
| int a[] = {1, 2, 3, 4}; |
| std::same_as<int*> auto ret = std::ranges::find_if(std::views::all(a), [](int){ return true; }); |
| assert(ret == a); |
| assert(*ret == 1); |
| } |
| |
| { |
| // check that std::invoke is used |
| struct S { int i; }; |
| S a[] = { S{1}, S{3}, S{2} }; |
| std::same_as<S*> auto ret = std::ranges::find_if(a, [](int) { return false; }, &S::i); |
| assert(ret == a + 3); |
| } |
| |
| { |
| // count projection and predicate invocation count |
| { |
| int a[] = {1, 2, 3, 4}; |
| int predicate_count = 0; |
| int projection_count = 0; |
| auto ret = std::ranges::find_if(a, a + 4, |
| [&](int i) { ++predicate_count; return i == 2; }, |
| [&](int i) { ++projection_count; return i; }); |
| assert(ret == a + 1); |
| assert(*ret == 2); |
| assert(predicate_count == 2); |
| assert(projection_count == 2); |
| } |
| { |
| int a[] = {1, 2, 3, 4}; |
| int predicate_count = 0; |
| int projection_count = 0; |
| auto ret = std::ranges::find_if(a, |
| [&](int i) { ++predicate_count; return i == 2; }, |
| [&](int i) { ++projection_count; return i; }); |
| assert(ret == a + 1); |
| assert(*ret == 2); |
| assert(predicate_count == 2); |
| assert(projection_count == 2); |
| } |
| } |
| |
| { |
| // check that the return type of `iter::operator*` doesn't change |
| { |
| NonConstComparable a[] = { NonConstComparable{} }; |
| auto ret = std::ranges::find_if(a, a + 1, [](auto&& e) { return e == NonConstComparable{}; }); |
| assert(ret == a); |
| } |
| { |
| NonConstComparable a[] = { NonConstComparable{} }; |
| auto ret = std::ranges::find_if(a, [](auto&& e) { return e == NonConstComparable{}; }); |
| assert(ret == a); |
| } |
| } |
| |
| { |
| // check that an empty range works |
| { |
| std::array<int ,0> a = {}; |
| auto ret = std::ranges::find_if(a.begin(), a.end(), [](int) { return true; }); |
| assert(ret == a.begin()); |
| } |
| { |
| std::array<int, 0> a = {}; |
| auto ret = std::ranges::find_if(a, [](int) { return true; }); |
| assert(ret == a.begin()); |
| } |
| } |
| |
| return true; |
| } |
| |
| int main(int, char**) { |
| test(); |
| static_assert(test()); |
| |
| return 0; |
| } |