| //===----------------------------------------------------------------------===// |
| // |
| // 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, weakly_incrementable O> |
| // requires indirectly_copyable<I, O> |
| // constexpr ranges::copy_n_result<I, O> |
| // ranges::copy_n(I first, iter_difference_t<I> n, O result); |
| |
| #include <algorithm> |
| #include <array> |
| #include <cassert> |
| #include <ranges> |
| |
| #include "almost_satisfies_types.h" |
| #include "test_iterators.h" |
| |
| template <class In, class Out = In, class Count = std::size_t> |
| concept HasCopyNIt = requires(In in, Count count, Out out) { std::ranges::copy_n(in, count, out); }; |
| |
| static_assert(HasCopyNIt<int*>); |
| static_assert(!HasCopyNIt<InputIteratorNotDerivedFrom>); |
| static_assert(!HasCopyNIt<InputIteratorNotIndirectlyReadable>); |
| static_assert(!HasCopyNIt<InputIteratorNotInputOrOutputIterator>); |
| static_assert(!HasCopyNIt<int*, WeaklyIncrementableNotMovable>); |
| struct NotIndirectlyCopyable {}; |
| static_assert(!HasCopyNIt<int*, NotIndirectlyCopyable*>); |
| static_assert(!HasCopyNIt<int*, int*, SentinelForNotSemiregular>); |
| static_assert(!HasCopyNIt<int*, int*, SentinelForNotWeaklyEqualityComparableWith>); |
| |
| static_assert(std::is_same_v<std::ranges::copy_result<int, long>, std::ranges::in_out_result<int, long>>); |
| |
| template <class In, class Out, class Sent = In> |
| constexpr void test_iterators() { |
| { // simple test |
| std::array in {1, 2, 3, 4}; |
| std::array<int, 4> out; |
| std::same_as<std::ranges::in_out_result<In, Out>> auto ret = |
| std::ranges::copy_n(In(in.data()), in.size(), Out(out.data())); |
| assert(in == out); |
| assert(base(ret.in) == in.data() + in.size()); |
| assert(base(ret.out) == out.data() + out.size()); |
| } |
| |
| { // check that an empty range works |
| std::array<int, 0> in; |
| std::array<int, 0> out; |
| auto ret = std::ranges::copy_n(In(in.data()), in.size(), Out(out.begin())); |
| assert(base(ret.in) == in.data()); |
| assert(base(ret.out) == out.data()); |
| } |
| } |
| |
| template <class Out> |
| constexpr void test_in_iterators() { |
| test_iterators<cpp20_input_iterator<int*>, Out, sentinel_wrapper<cpp20_input_iterator<int*>>>(); |
| test_iterators<forward_iterator<int*>, Out>(); |
| test_iterators<bidirectional_iterator<int*>, Out>(); |
| test_iterators<random_access_iterator<int*>, Out>(); |
| test_iterators<contiguous_iterator<int*>, Out>(); |
| } |
| |
| template <class Out> |
| constexpr void test_proxy_in_iterators() { |
| test_iterators<ProxyIterator<cpp20_input_iterator<int*>>, Out, sentinel_wrapper<ProxyIterator<cpp20_input_iterator<int*>>>>(); |
| test_iterators<ProxyIterator<forward_iterator<int*>>, Out>(); |
| test_iterators<ProxyIterator<bidirectional_iterator<int*>>, Out>(); |
| test_iterators<ProxyIterator<random_access_iterator<int*>>, Out>(); |
| test_iterators<ProxyIterator<contiguous_iterator<int*>>, Out>(); |
| } |
| |
| constexpr bool test() { |
| test_in_iterators<cpp20_input_iterator<int*>>(); |
| test_in_iterators<forward_iterator<int*>>(); |
| test_in_iterators<bidirectional_iterator<int*>>(); |
| test_in_iterators<random_access_iterator<int*>>(); |
| test_in_iterators<contiguous_iterator<int*>>(); |
| |
| test_proxy_in_iterators<ProxyIterator<cpp20_input_iterator<int*>>>(); |
| test_proxy_in_iterators<ProxyIterator<forward_iterator<int*>>>(); |
| test_proxy_in_iterators<ProxyIterator<bidirectional_iterator<int*>>>(); |
| test_proxy_in_iterators<ProxyIterator<random_access_iterator<int*>>>(); |
| test_proxy_in_iterators<ProxyIterator<contiguous_iterator<int*>>>(); |
| |
| { // check that every element is copied exactly once |
| struct CopyOnce { |
| bool copied = false; |
| constexpr CopyOnce() = default; |
| constexpr CopyOnce(const CopyOnce& other) = delete; |
| constexpr CopyOnce& operator=(const CopyOnce& other) { |
| assert(!other.copied); |
| copied = true; |
| return *this; |
| } |
| }; |
| std::array<CopyOnce, 4> in {}; |
| std::array<CopyOnce, 4> out {}; |
| auto ret = std::ranges::copy_n(in.data(), in.size(), out.begin()); |
| assert(ret.in == in.end()); |
| assert(ret.out == out.end()); |
| assert(std::all_of(out.begin(), out.end(), [](const auto& e) { return e.copied; })); |
| } |
| |
| return true; |
| } |
| |
| int main(int, char**) { |
| test(); |
| static_assert(test()); |
| |
| return 0; |
| } |