| //===----------------------------------------------------------------------===// |
| // |
| // 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 |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // UNSUPPORTED: c++03, c++11, c++14, c++17 |
| |
| // std::views::take_while |
| |
| #include <algorithm> |
| #include <cassert> |
| #include <ranges> |
| #include <type_traits> |
| #include <utility> |
| |
| #include "types.h" |
| |
| struct Pred { |
| constexpr bool operator()(int i) const { return i < 3; } |
| }; |
| |
| struct Foo {}; |
| |
| struct MoveOnlyView : IntBufferViewBase { |
| using IntBufferViewBase::IntBufferViewBase; |
| MoveOnlyView(const MoveOnlyView&) = delete; |
| MoveOnlyView& operator=(const MoveOnlyView&) = delete; |
| MoveOnlyView(MoveOnlyView&&) = default; |
| MoveOnlyView& operator=(MoveOnlyView&&) = default; |
| constexpr const int* begin() const { return buffer_; } |
| constexpr const int* end() const { return buffer_ + size_; } |
| }; |
| |
| static_assert(!std::is_invocable_v<decltype((std::views::take_while))>); |
| static_assert(std::is_invocable_v<decltype((std::views::take_while)), int>); |
| static_assert(std::is_invocable_v<decltype((std::views::take_while)), Pred>); |
| static_assert(!std::is_invocable_v<decltype((std::views::take_while)), int, Pred>); |
| static_assert(std::is_invocable_v<decltype((std::views::take_while)), int (&)[2], Pred>); |
| static_assert(!std::is_invocable_v<decltype((std::views::take_while)), Foo (&)[2], Pred>); |
| static_assert(std::is_invocable_v<decltype((std::views::take_while)), MoveOnlyView, Pred>); |
| |
| template <class View, class T> |
| concept CanBePiped = |
| requires(View&& view, T&& t) { |
| { std::forward<View>(view) | std::forward<T>(t) }; |
| }; |
| |
| static_assert(!CanBePiped<MoveOnlyView, decltype(std::views::take_while)>); |
| static_assert(CanBePiped<MoveOnlyView, decltype(std::views::take_while(Pred{}))>); |
| static_assert(!CanBePiped<int, decltype(std::views::take_while(Pred{}))>); |
| static_assert(CanBePiped<int (&)[2], decltype(std::views::take_while(Pred{}))>); |
| static_assert(!CanBePiped<Foo (&)[2], decltype(std::views::take_while(Pred{}))>); |
| |
| constexpr bool test() { |
| int buff[] = {1, 2, 3, 4, 3, 2, 1}; |
| |
| // Test `views::take_while(p)(v)` |
| { |
| using Result = std::ranges::take_while_view<MoveOnlyView, Pred>; |
| std::same_as<Result> decltype(auto) result = std::views::take_while(Pred{})(MoveOnlyView{buff}); |
| auto expected = {1, 2}; |
| assert(std::ranges::equal(result, expected)); |
| } |
| { |
| auto const partial = std::views::take_while(Pred{}); |
| using Result = std::ranges::take_while_view<MoveOnlyView, Pred>; |
| std::same_as<Result> decltype(auto) result = partial(MoveOnlyView{buff}); |
| auto expected = {1, 2}; |
| assert(std::ranges::equal(result, expected)); |
| } |
| |
| // Test `v | views::take_while(p)` |
| { |
| using Result = std::ranges::take_while_view<MoveOnlyView, Pred>; |
| std::same_as<Result> decltype(auto) result = MoveOnlyView{buff} | std::views::take_while(Pred{}); |
| auto expected = {1, 2}; |
| assert(std::ranges::equal(result, expected)); |
| } |
| { |
| auto const partial = std::views::take_while(Pred{}); |
| using Result = std::ranges::take_while_view<MoveOnlyView, Pred>; |
| std::same_as<Result> decltype(auto) result = MoveOnlyView{buff} | partial; |
| auto expected = {1, 2}; |
| assert(std::ranges::equal(result, expected)); |
| } |
| |
| // Test `views::take_while(v, p)` |
| { |
| using Result = std::ranges::take_while_view<MoveOnlyView, Pred>; |
| std::same_as<Result> decltype(auto) result = std::views::take_while(MoveOnlyView{buff}, Pred{}); |
| auto expected = {1, 2}; |
| assert(std::ranges::equal(result, expected)); |
| } |
| |
| // Test adaptor | adaptor |
| { |
| struct Pred2 { |
| constexpr bool operator()(int i) const { return i < 2; } |
| }; |
| auto const partial = std::views::take_while(Pred{}) | std::views::take_while(Pred2{}); |
| using Result = std::ranges::take_while_view<std::ranges::take_while_view<MoveOnlyView, Pred>, Pred2>; |
| std::same_as<Result> decltype(auto) result = MoveOnlyView{buff} | partial; |
| auto expected = {1}; |
| assert(std::ranges::equal(result, expected)); |
| } |
| return true; |
| } |
| |
| int main(int, char**) { |
| test(); |
| static_assert(test()); |
| |
| return 0; |
| } |