| //===----------------------------------------------------------------------===// |
| // |
| // 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, c++20 |
| |
| // template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2, |
| // class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity> |
| // requires indirectly_comparable<I1, I2, Pred, Proj1, Proj2> |
| // constexpr bool ranges::starts_with(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = {}, |
| // Proj1 proj1 = {}, Proj2 proj2 = {}); |
| // template<input_range R1, input_range R2, class Pred = ranges::equal_to, class Proj1 = identity, |
| // class Proj2 = identity> |
| // requires indirectly_comparable<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2> |
| // constexpr bool ranges::starts_with(R1&& r1, R2&& r2, Pred pred = {}, |
| // Proj1 proj1 = {}, Proj2 proj2 = {}); |
| |
| #include <algorithm> |
| #include <array> |
| #include <ranges> |
| |
| #include "almost_satisfies_types.h" |
| #include "test_iterators.h" |
| |
| template <class Iter1, class Sent1 = Iter1, class Iter2 = int*, class Sent2 = Iter2> |
| concept HasStartsWithIt = requires(Iter1 first1, Sent1 last1, Iter2 first2, Sent2 last2) { |
| std::ranges::starts_with(first1, last1, first2, last2); |
| }; |
| |
| static_assert(HasStartsWithIt<int*>); |
| static_assert(HasStartsWithIt<ForwardIteratorNotDerivedFrom>); |
| static_assert(HasStartsWithIt<ForwardIteratorNotIncrementable>); |
| static_assert(!HasStartsWithIt<int*, SentinelForNotSemiregular>); |
| static_assert(!HasStartsWithIt<int*, int*, int**>); // not indirectly comparable |
| static_assert(!HasStartsWithIt<int*, SentinelForNotWeaklyEqualityComparableWith>); |
| static_assert(HasStartsWithIt<int*, int*, ForwardIteratorNotDerivedFrom>); |
| static_assert(HasStartsWithIt<int*, int*, ForwardIteratorNotIncrementable>); |
| static_assert(!HasStartsWithIt<int*, int*, int*, SentinelForNotSemiregular>); |
| static_assert(!HasStartsWithIt<int*, int*, int*, SentinelForNotWeaklyEqualityComparableWith>); |
| |
| template <class Range1, class Range2 = UncheckedRange<int*>> |
| concept HasStartsWithR = requires(Range1 range1, Range2 range2) { std::ranges::starts_with(range1, range2); }; |
| |
| static_assert(HasStartsWithR<UncheckedRange<int*>>); |
| static_assert(HasStartsWithR<ForwardRangeNotDerivedFrom>); |
| static_assert(!HasStartsWithR<ForwardIteratorNotIncrementable>); |
| static_assert(!HasStartsWithR<ForwardRangeNotSentinelSemiregular>); |
| static_assert(!HasStartsWithR<ForwardRangeNotSentinelEqualityComparableWith>); |
| static_assert(!HasStartsWithR<UncheckedRange<int*>, UncheckedRange<int**>>); // not indirectly comparable |
| static_assert(HasStartsWithR<UncheckedRange<int*>, ForwardRangeNotDerivedFrom>); |
| static_assert(HasStartsWithR<UncheckedRange<int*>, ForwardRangeNotIncrementable>); |
| static_assert(!HasStartsWithR<UncheckedRange<int*>, ForwardRangeNotSentinelSemiregular>); |
| static_assert(!HasStartsWithR<UncheckedRange<int*>, ForwardRangeNotSentinelEqualityComparableWith>); |
| |
| // clang-format off |
| template <class Iter1, class Sent1 = Iter1, class Iter2, class Sent2 = Iter2> |
| constexpr void test_iterators() { |
| { // simple tests |
| { |
| int a[] = {1, 2, 3, 4, 5, 6}; |
| int p[] = {1, 2}; |
| std::same_as<bool> decltype(auto) ret = |
| std::ranges::starts_with(Iter1(a), Sent1(Iter1(a + 6)), Iter2(p), Sent2(Iter2(p + 2))); |
| assert(ret); |
| } |
| { |
| int a[] = {1, 2, 3, 4, 5, 6}; |
| int p[] = {1, 2}; |
| auto whole = std::ranges::subrange(Iter1(a), Sent1(Iter1(a + 6))); |
| auto prefix = std::ranges::subrange(Iter2(p), Sent2(Iter2(p + 2))); |
| std::same_as<bool> decltype(auto) ret = std::ranges::starts_with(whole, prefix); |
| assert(ret); |
| } |
| } |
| |
| { // prefix doesn't match |
| { |
| int a[] = {1, 2, 3, 4, 5, 6}; |
| int p[] = {4, 5, 6}; |
| std::same_as<bool> decltype(auto) ret = |
| std::ranges::starts_with(Iter1(a), Sent1(Iter1(a + 6)), Iter2(p), Sent2(Iter2(p + 3))); |
| assert(!ret); |
| } |
| { |
| int a[] = {1, 2, 3, 4, 5, 6}; |
| int p[] = {4, 5, 6}; |
| auto whole = std::ranges::subrange(Iter1(a), Sent1(Iter1(a + 6))); |
| auto prefix = std::ranges::subrange(Iter2(p), Sent2(Iter2(p + 3))); |
| std::same_as<bool> decltype(auto) ret = std::ranges::starts_with(whole, prefix); |
| assert(!ret); |
| } |
| } |
| |
| { // range and prefix are identical |
| { |
| int a[] = {1, 2, 3, 4, 5, 6}; |
| int p[] = {1, 2, 3, 4, 5, 6}; |
| std::same_as<bool> decltype(auto) ret = |
| std::ranges::starts_with(Iter1(a), Sent1(Iter1(a + 6)), Iter2(p), Sent2(Iter2(p + 6))); |
| assert(ret); |
| } |
| { |
| int a[] = {1, 2, 3, 4, 5, 6}; |
| int p[] = {1, 2, 3, 4, 5, 6}; |
| auto whole = std::ranges::subrange(Iter1(a), Sent1(Iter1(a + 6))); |
| auto prefix = std::ranges::subrange(Iter2(p), Sent2(Iter2(p + 6))); |
| std::same_as<bool> decltype(auto) ret = std::ranges::starts_with(whole, prefix); |
| assert(ret); |
| } |
| } |
| |
| { // prefix is longer than range |
| { |
| int a[] = {1, 2, 3, 4, 5, 6}; |
| int p[] = {1, 2, 3, 4, 5, 6, 7, 8}; |
| std::same_as<bool> decltype(auto) ret = |
| std::ranges::starts_with(Iter1(a), Sent1(Iter1(a + 6)), Iter2(p), Sent2(Iter2(p + 8))); |
| assert(!ret); |
| } |
| { |
| int a[] = {1, 2, 3, 4, 5, 6}; |
| int p[] = {1, 2, 3, 4, 5, 6, 7, 8}; |
| auto whole = std::ranges::subrange(Iter1(a), Sent1(Iter1(a + 6))); |
| auto prefix = std::ranges::subrange(Iter2(p), Sent2(Iter2(p + 8))); |
| std::same_as<bool> decltype(auto) ret = std::ranges::starts_with(whole, prefix); |
| assert(!ret); |
| } |
| } |
| |
| { // prefix has zero length |
| { |
| int a[] = {1, 2, 3, 4, 5, 6}; |
| int p[] = {}; |
| std::same_as<bool> decltype(auto) ret = |
| std::ranges::starts_with(Iter1(a), Sent1(Iter1(a + 6)), Iter2(p), Sent2(Iter2(p))); |
| assert(ret); |
| } |
| { |
| int a[] = {1, 2, 3, 4, 5, 6}; |
| int p[] = {}; |
| auto whole = std::ranges::subrange(Iter1(a), Sent1(Iter1(a + 6))); |
| auto prefix = std::ranges::subrange(Iter2(p), Sent2(Iter2(p))); |
| std::same_as<bool> decltype(auto) ret = std::ranges::starts_with(whole, prefix); |
| assert(ret); |
| } |
| } |
| |
| { // range has zero length |
| { |
| int a[] = {}; |
| int p[] = {1, 2, 3, 4, 5, 6, 7, 8}; |
| std::same_as<bool> decltype(auto) ret = |
| std::ranges::starts_with(Iter1(a), Sent1(Iter1(a)), Iter2(p), Sent2(Iter2(p + 8))); |
| assert(!ret); |
| } |
| { |
| int a[] = {}; |
| int p[] = {1, 2, 3, 4, 5, 6, 7, 8}; |
| auto whole = std::ranges::subrange(Iter1(a), Sent1(Iter1(a))); |
| auto prefix = std::ranges::subrange(Iter2(p), Sent2(Iter2(p + 8))); |
| std::same_as<bool> decltype(auto) ret = std::ranges::starts_with(whole, prefix); |
| assert(!ret); |
| } |
| } |
| |
| { // check that the predicate is used |
| { |
| int a[] = {11, 8, 3, 4, 0, 6}; |
| int p[] = {1, 12}; |
| std::same_as<bool> decltype(auto) ret = std::ranges::starts_with( |
| Iter1(a), Sent1(Iter1(a + 6)), Iter2(p), Sent2(Iter2(p + 2)), [](int l, int r) { return l > r; }); |
| assert(!ret); |
| } |
| { |
| int a[] = {11, 8, 3, 4, 0, 6}; |
| int p[] = {1, 12}; |
| auto whole = std::ranges::subrange(Iter1(a), Sent1(Iter1(a + 6))); |
| auto prefix = std::ranges::subrange(Iter2(p), Sent2(Iter2(p + 2))); |
| std::same_as<bool> decltype(auto) ret = std::ranges::starts_with(whole, prefix, [](int l, int r) { return l > r; }); |
| assert(!ret); |
| } |
| } |
| |
| { // check that the projections are used |
| { |
| int a[] = {1, 3, 5, 1, 5, 6}; |
| int p[] = {2, 3, 4}; |
| std::same_as<bool> decltype(auto) ret = std::ranges::starts_with( |
| Iter1(a), |
| Sent1(Iter1(a + 6)), |
| Iter2(p), |
| Sent2(Iter2(p + 3)), |
| {}, |
| [](int i) { return i + 3; }, |
| [](int i) { return i * 2; }); |
| assert(ret); |
| } |
| { |
| int a[] = {1, 3, 5, 1, 5, 6}; |
| int p[] = {2, 3, 4}; |
| auto whole = std::ranges::subrange(Iter1(a), Sent1(Iter1(a + 6))); |
| auto prefix = std::ranges::subrange(Iter2(p), Sent2(Iter2(p + 3))); |
| std::same_as<bool> decltype(auto) ret = std::ranges::starts_with( |
| whole, prefix, {}, [](int i) { return i + 3; }, [](int i) { return i * 2; }); |
| assert(ret); |
| } |
| } |
| } |
| |
| constexpr bool test() { |
| types::for_each(types::cpp20_input_iterator_list<int*>{}, []<class Iter2>() { |
| types::for_each(types::cpp20_input_iterator_list<int*>{}, []<class Iter1>() { |
| if constexpr (std::forward_iterator<Iter1> && std::forward_iterator<Iter2>) |
| test_iterators<Iter1, Iter1, Iter2, Iter2>(); |
| if constexpr (std::forward_iterator<Iter2>) |
| test_iterators<Iter1, sized_sentinel<Iter1>, Iter2, Iter2>(); |
| if constexpr (std::forward_iterator<Iter1>) |
| test_iterators<Iter1, Iter1, Iter2, sized_sentinel<Iter2>>(); |
| test_iterators<Iter1, sized_sentinel<Iter1>, Iter2, sized_sentinel<Iter2>>(); |
| }); |
| }); |
| |
| { // check that std::invoke is used |
| struct S { |
| int i; |
| |
| constexpr S identity() { return *this; } |
| |
| constexpr bool compare(const S& s) { return i == s.i; } |
| }; |
| { |
| S a[] = {{1}, {2}, {3}, {4}}; |
| S p[] = {{1}, {2}}; |
| auto ret = std::ranges::starts_with(a, a + 4, p, p + 2, &S::compare, &S::identity, &S::identity); |
| assert(ret); |
| } |
| { |
| S a[] = {{1}, {2}, {3}, {4}}; |
| S p[] = {{1}, {2}}; |
| auto ret = std::ranges::starts_with(a, p, &S::compare, &S::identity, &S::identity); |
| assert(ret); |
| } |
| } |
| |
| return true; |
| } |
| |
| int main(int, char**) { |
| test(); |
| static_assert(test()); |
| |
| return 0; |
| } |