48 lines · cpp
1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9// UNSUPPORTED: c++03, c++11, c++14, c++1710 11// concept checking12// template<view V, class Pred>13// requires input_range<V> && is_object_v<Pred> &&14// indirect_unary_predicate<const Pred, iterator_t<V>>15// class drop_while_view;16 17#include <array>18#include <ranges>19 20#include "test_iterators.h"21 22template <class It>23using Range = std::ranges::subrange<It, sentinel_wrapper<It>>;24 25template <class Val = int>26struct Pred {27 bool operator()(const Val&) const;28};29 30template <class V, class Pred>31concept HasDropWhileView = requires { typename std::ranges::drop_while_view<V, Pred>; };32 33static_assert(HasDropWhileView<Range<int*>, bool (*)(int)>);34static_assert(HasDropWhileView<Range<int*>, Pred<int>>);35 36// !view<V>37static_assert(!HasDropWhileView<std::array<int, 5>, Pred<int>>);38 39// !input_range40static_assert(!HasDropWhileView<Range<cpp20_output_iterator<int*>>, bool (*)(int)>);41 42// !is_object_v<Pred>43static_assert(!HasDropWhileView<Range<int*>, Pred<int>&>);44 45// !indirect_unary_predicate<const Pred, iterator_t<V>>46static_assert(!HasDropWhileView<Range<int*>, int>);47static_assert(!HasDropWhileView<Range<int**>, Pred<int>>);48