| //===----------------------------------------------------------------------===// |
| // |
| // 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 |
| // UNSUPPORTED: !c++experimental |
| |
| // constexpr auto begin(); |
| // constexpr auto begin() const |
| // requires input_range<const V> && |
| // is_reference_v<range_reference_t<const V>>; |
| |
| #include <cassert> |
| #include <ranges> |
| |
| #include "types.h" |
| |
| struct NonSimpleParentView : std::ranges::view_base { |
| ChildView* begin() { return nullptr; } |
| const ChildView* begin() const; |
| const ChildView* end() const; |
| }; |
| |
| struct SimpleParentView : std::ranges::view_base { |
| const ChildView* begin() const; |
| const ChildView* end() const; |
| }; |
| |
| struct ConstNotRange : std::ranges::view_base { |
| const ChildView* begin(); |
| const ChildView* end(); |
| }; |
| static_assert(std::ranges::range<ConstNotRange>); |
| static_assert(!std::ranges::range<const ConstNotRange>); |
| |
| template <class T> |
| concept HasConstBegin = requires(const T& t) { t.begin(); }; |
| |
| constexpr bool test() { |
| int buffer[4][4] = {{1111, 2222, 3333, 4444}, {555, 666, 777, 888}, {99, 1010, 1111, 1212}, {13, 14, 15, 16}}; |
| |
| { |
| ChildView children[4] = {ChildView(buffer[0]), ChildView(buffer[1]), ChildView(buffer[2]), ChildView(buffer[3])}; |
| auto jv = std::ranges::join_view(ParentView{children}); |
| assert(*jv.begin() == 1111); |
| } |
| |
| { |
| CopyableChild children[4] = {CopyableChild(buffer[0], 4), CopyableChild(buffer[1], 0), CopyableChild(buffer[2], 1), |
| CopyableChild(buffer[3], 0)}; |
| auto jv = std::ranges::join_view(ParentView{children}); |
| assert(*jv.begin() == 1111); |
| } |
| |
| // Parent is empty. |
| { |
| CopyableChild children[4] = {CopyableChild(buffer[0]), CopyableChild(buffer[1]), CopyableChild(buffer[2]), |
| CopyableChild(buffer[3])}; |
| std::ranges::join_view jv(ParentView(children, 0)); |
| assert(jv.begin() == jv.end()); |
| } |
| |
| // Parent size is one. |
| { |
| CopyableChild children[1] = {CopyableChild(buffer[0])}; |
| std::ranges::join_view jv(ParentView(children, 1)); |
| assert(*jv.begin() == 1111); |
| } |
| |
| // Parent and child size is one. |
| { |
| CopyableChild children[1] = {CopyableChild(buffer[0], 1)}; |
| std::ranges::join_view jv(ParentView(children, 1)); |
| assert(*jv.begin() == 1111); |
| } |
| |
| // Parent size is one child is empty |
| { |
| CopyableChild children[1] = {CopyableChild(buffer[0], 0)}; |
| std::ranges::join_view jv(ParentView(children, 1)); |
| assert(jv.begin() == jv.end()); |
| } |
| |
| // Has all empty children. |
| { |
| CopyableChild children[4] = {CopyableChild(buffer[0], 0), CopyableChild(buffer[1], 0), CopyableChild(buffer[2], 0), |
| CopyableChild(buffer[3], 0)}; |
| auto jv = std::ranges::join_view(ParentView{children}); |
| assert(jv.begin() == jv.end()); |
| } |
| |
| // First child is empty, others are not. |
| { |
| CopyableChild children[4] = {CopyableChild(buffer[0], 4), CopyableChild(buffer[1], 0), CopyableChild(buffer[2], 0), |
| CopyableChild(buffer[3], 0)}; |
| auto jv = std::ranges::join_view(ParentView{children}); |
| assert(*jv.begin() == 1111); |
| } |
| |
| // Last child is empty, others are not. |
| { |
| CopyableChild children[4] = {CopyableChild(buffer[0], 4), CopyableChild(buffer[1], 4), CopyableChild(buffer[2], 4), |
| CopyableChild(buffer[3], 0)}; |
| auto jv = std::ranges::join_view(ParentView{children}); |
| assert(*jv.begin() == 1111); |
| } |
| |
| { |
| std::ranges::join_view jv(buffer); |
| assert(*jv.begin() == 1111); |
| } |
| |
| { |
| const std::ranges::join_view jv(buffer); |
| assert(*jv.begin() == 1111); |
| static_assert(HasConstBegin<decltype(jv)>); |
| } |
| |
| // !input_range<const V> |
| { |
| std::ranges::join_view jv{ConstNotRange{}}; |
| static_assert(!HasConstBegin<decltype(jv)>); |
| } |
| |
| // !is_reference_v<range_reference_t<const V>> |
| { |
| auto innerRValueRange = std::views::iota(0, 5) | std::views::transform([](int) { return ChildView{}; }); |
| static_assert(!std::is_reference_v<std::ranges::range_reference_t<const decltype(innerRValueRange)>>); |
| std::ranges::join_view jv{innerRValueRange}; |
| static_assert(!HasConstBegin<decltype(jv)>); |
| } |
| |
| // !simple-view<V> |
| { |
| std::ranges::join_view<NonSimpleParentView> jv; |
| static_assert(!std::same_as<decltype(jv.begin()), decltype(std::as_const(jv).begin())>); |
| } |
| |
| // simple-view<V> && is_reference_v<range_reference_t<V>>; |
| { |
| std::ranges::join_view<SimpleParentView> jv; |
| static_assert(std::same_as<decltype(jv.begin()), decltype(std::as_const(jv).begin())>); |
| } |
| |
| return true; |
| } |
| |
| int main(int, char**) { |
| test(); |
| static_assert(test()); |
| |
| return 0; |
| } |