| //===----------------------------------------------------------------------===// |
| // |
| // 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 end() requires (!simple-view<V>) |
| // { return sentinel<false>(ranges::end(base_), addressof(*pred_)); } |
| // constexpr auto end() const |
| // requires range<const V> && |
| // indirect_unary_predicate<const Pred, iterator_t<const V>> |
| // { return sentinel<true>(ranges::end(base_), addressof(*pred_)); } |
| |
| #include <cassert> |
| #include <ranges> |
| #include <type_traits> |
| #include <utility> |
| |
| #include "types.h" |
| |
| // Test Constraints |
| template <class T> |
| concept HasConstEnd = requires(const T& ct) { ct.end(); }; |
| |
| template <class T> |
| concept HasEnd = requires(T& t) { t.end(); }; |
| |
| template <class T> |
| concept HasConstAndNonConstEnd = |
| HasConstEnd<T> && requires(T& t, const T& ct) { requires !std::same_as<decltype(t.end()), decltype(ct.end())>; }; |
| |
| template <class T> |
| concept HasOnlyNonConstEnd = HasEnd<T> && !HasConstEnd<T>; |
| |
| template <class T> |
| concept HasOnlyConstEnd = HasConstEnd<T> && !HasConstAndNonConstEnd<T>; |
| |
| struct Pred { |
| constexpr bool operator()(int i) const { return i < 5; } |
| }; |
| |
| static_assert(HasOnlyConstEnd<std::ranges::take_while_view<SimpleView, Pred>>); |
| |
| static_assert(HasOnlyNonConstEnd<std::ranges::take_while_view<ConstNotRange, Pred>>); |
| |
| static_assert(HasConstAndNonConstEnd<std::ranges::take_while_view<NonSimple, Pred>>); |
| |
| struct NotPredForConst { |
| constexpr bool operator()(int& i) const { return i > 5; } |
| }; |
| static_assert(HasOnlyNonConstEnd<std::ranges::take_while_view<NonSimple, NotPredForConst>>); |
| |
| constexpr bool test() { |
| // simple-view |
| { |
| int buffer[] = {1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1}; |
| SimpleView v{buffer}; |
| std::ranges::take_while_view twv(v, Pred{}); |
| decltype(auto) it1 = twv.end(); |
| assert(it1 == buffer + 4); |
| decltype(auto) it2 = std::as_const(twv).end(); |
| assert(it2 == buffer + 4); |
| |
| static_assert(std::same_as<decltype(it1), decltype(it2)>); |
| } |
| |
| // const not range |
| { |
| int buffer[] = {1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1}; |
| ConstNotRange v{buffer}; |
| std::ranges::take_while_view twv(v, Pred{}); |
| decltype(auto) it1 = twv.end(); |
| assert(it1 == buffer + 4); |
| } |
| |
| // NonSimple |
| { |
| int buffer[] = {1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1}; |
| NonSimple v{buffer}; |
| std::ranges::take_while_view twv(v, Pred{}); |
| decltype(auto) it1 = twv.end(); |
| assert(it1 == buffer + 4); |
| decltype(auto) it2 = std::as_const(twv).end(); |
| assert(it2 == buffer + 4); |
| |
| static_assert(!std::same_as<decltype(it1), decltype(it2)>); |
| } |
| |
| // NotPredForConst |
| // LWG 3450: The const overloads of `take_while_view::begin/end` are underconstrained |
| { |
| int buffer[] = {1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1}; |
| NonSimple v{buffer}; |
| std::ranges::take_while_view twv(v, NotPredForConst{}); |
| decltype(auto) it1 = twv.end(); |
| assert(it1 == buffer); |
| } |
| |
| return true; |
| } |
| |
| int main(int, char**) { |
| test(); |
| static_assert(test()); |
| return 0; |
| } |