| //===----------------------------------------------------------------------===// |
| // |
| // 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 |
| |
| // constexpr auto begin(); |
| // constexpr auto begin() const requires forward_range<View> && forward_range<const View>; |
| |
| #include <ranges> |
| |
| #include <cassert> |
| #include <utility> |
| #include "test_iterators.h" |
| #include "types.h" |
| |
| template <class View> |
| concept ConstBeginDisabled = !requires (const View v) { |
| { (*v.begin()) }; |
| }; |
| |
| constexpr bool test() { |
| // non-const: forward_range<View> && simple-view<View> -> outer-iterator<Const = true> |
| // const: forward_range<View> && forward_range<const View> -> outer-iterator<Const = true> |
| { |
| using V = ForwardView; |
| using P = V; |
| |
| static_assert(std::ranges::forward_range<V>); |
| static_assert(std::ranges::forward_range<const V>); |
| LIBCPP_STATIC_ASSERT(std::ranges::__simple_view<V>); |
| LIBCPP_STATIC_ASSERT(std::ranges::__simple_view<P>); |
| |
| { |
| std::ranges::lazy_split_view<V, P> v; |
| auto it = v.begin(); |
| static_assert(std::is_same_v<decltype(it)::iterator_concept, std::forward_iterator_tag>); |
| static_assert(std::is_same_v<decltype(*(*it).begin()), const char&>); |
| } |
| |
| { |
| const std::ranges::lazy_split_view<V, P> cv; |
| auto it = cv.begin(); |
| static_assert(std::is_same_v<decltype(it)::iterator_concept, std::forward_iterator_tag>); |
| static_assert(std::is_same_v<decltype(*(*it).begin()), const char&>); |
| } |
| } |
| |
| // non-const: forward_range<View> && !simple-view<View> -> outer-iterator<Const = false> |
| // const: forward_range<View> && forward_range<const View> -> outer-iterator<Const = true> |
| { |
| using V = ForwardDiffView; |
| using P = V; |
| |
| static_assert(std::ranges::forward_range<V>); |
| static_assert(std::ranges::forward_range<const V>); |
| LIBCPP_STATIC_ASSERT(!std::ranges::__simple_view<V>); |
| LIBCPP_STATIC_ASSERT(!std::ranges::__simple_view<P>); |
| |
| { |
| std::ranges::lazy_split_view<V, P> v; |
| auto it = v.begin(); |
| static_assert(std::is_same_v<decltype(it)::iterator_concept, std::forward_iterator_tag>); |
| static_assert(std::is_same_v<decltype(*(*it).begin()), char&>); |
| } |
| |
| { |
| const std::ranges::lazy_split_view<V, P> cv; |
| auto it = cv.begin(); |
| static_assert(std::is_same_v<decltype(it)::iterator_concept, std::forward_iterator_tag>); |
| static_assert(std::is_same_v<decltype(*(*it).begin()), const char&>); |
| } |
| } |
| |
| // non-const: forward_range<View> && !simple-view<View> -> outer-iterator<Const = false> |
| // const: forward_range<View> && !forward_range<const View> -> disabled |
| { |
| using V = ForwardOnlyIfNonConstView; |
| using P = V; |
| static_assert(std::ranges::forward_range<V>); |
| static_assert(!std::ranges::forward_range<const V>); |
| LIBCPP_STATIC_ASSERT(!std::ranges::__simple_view<V>); |
| LIBCPP_STATIC_ASSERT(!std::ranges::__simple_view<P>); |
| |
| std::ranges::lazy_split_view<V, P> v; |
| auto it = v.begin(); |
| static_assert(std::is_same_v<decltype(it)::iterator_concept, std::forward_iterator_tag>); |
| static_assert(std::is_same_v<decltype(*(*it).begin()), const char&>); |
| |
| static_assert(ConstBeginDisabled<decltype(v)>); |
| } |
| |
| // non-const: forward_range<View> && simple-view<View> && !simple-view<Pattern> -> outer-iterator<Const = false> |
| // const: forward_range<View> && forward_range<const View> -> outer-iterator<Const = true> |
| { |
| using V = ForwardView; |
| using P = ForwardOnlyIfNonConstView; |
| |
| static_assert(std::ranges::forward_range<V>); |
| static_assert(std::ranges::forward_range<const V>); |
| LIBCPP_STATIC_ASSERT(std::ranges::__simple_view<V>); |
| LIBCPP_STATIC_ASSERT(!std::ranges::__simple_view<P>); |
| |
| { |
| std::ranges::lazy_split_view<V, P> v; |
| auto it = v.begin(); |
| static_assert(std::is_same_v<decltype(it)::iterator_concept, std::forward_iterator_tag>); |
| static_assert(std::is_same_v<decltype(*(*it).begin()), const char&>); |
| } |
| |
| { |
| const std::ranges::lazy_split_view<V, P> cv; |
| auto it = cv.begin(); |
| static_assert(std::is_same_v<decltype(it)::iterator_concept, std::forward_iterator_tag>); |
| static_assert(std::is_same_v<decltype(*(*it).begin()), const char&>); |
| } |
| } |
| |
| // non-const: !forward_range<View> && tiny-range<Pattern> -> outer-iterator<Const = false> |
| // const: !forward_range<View> -> disabled |
| { |
| using V = InputView; |
| using P = ForwardTinyView; |
| |
| static_assert(!std::ranges::forward_range<V>); |
| static_assert(std::ranges::forward_range<P>); |
| |
| std::ranges::lazy_split_view<V, P> v; |
| auto it = v.begin(); |
| static_assert(std::is_same_v<decltype(it)::iterator_concept, std::input_iterator_tag>); |
| static_assert(std::is_same_v<decltype(*(*it).begin()), char&>); |
| |
| static_assert(ConstBeginDisabled<decltype(v)>); |
| } |
| |
| return true; |
| } |
| |
| int main(int, char**) { |
| test(); |
| static_assert(test()); |
| |
| return 0; |
| } |