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-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 // UNSUPPORTED: c++03, c++11, c++14, c++17
10
11 // constexpr explicit inner-iterator::inner-iterator(outer-iterator<Const> i);
12
13 #include <ranges>
14
15 #include "../types.h"
16
17 static_assert(!std::is_constructible_v<InnerIterNonConst, OuterIterConst>);
18
19 template <class Inner, class Outer>
test_impl()20 constexpr void test_impl() {
21 [[maybe_unused]] Inner i(Outer{});
22 // Verify that the constructor is `explicit`.
23 static_assert(!std::is_convertible_v<Outer, Inner>);
24 }
25
test()26 constexpr bool test() {
27 test_impl<InnerIterForward, OuterIterForward>();
28 test_impl<InnerIterInput, OuterIterInput>();
29 // Is only constructible if both the outer and the inner iterators have the same constness.
30 test_impl<InnerIterConst, OuterIterConst>();
31 // Note: this works because of an implicit conversion (`OuterIterNonConst` is converted to `OuterIterConst`).
32 test_impl<InnerIterConst, OuterIterNonConst>();
33 test_impl<InnerIterNonConst, OuterIterNonConst>();
34
35 return true;
36 }
37
main(int,char **)38 int main(int, char**) {
39 test();
40 static_assert(test());
41
42 return 0;
43 }
44