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//===----------------------------------------------------------------------===//
//
// 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
// elements_view() requires default_initializable<V> = default;
#include <cassert>
#include <ranges>
#include <tuple>
#include <type_traits>
template <bool DefaultInitializable>
struct View : std::ranges::view_base {
int i = 42;
constexpr explicit View()
requires DefaultInitializable
= default;
std::tuple<int>* begin() const;
std::tuple<int>* end() const;
};
// clang-format off
static_assert( std::is_default_constructible_v<std::ranges::elements_view<View<true >, 0>>);
static_assert(!std::is_default_constructible_v<std::ranges::elements_view<View<false>, 0>>);
// clang-format on
constexpr bool test() {
{
std::ranges::elements_view<View<true>, 0> ev = {};
assert(ev.base().i == 42);
}
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
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