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 // UNSUPPORTED: libcpp-has-no-incomplete-ranges
11 
12 // template<class R>
13 //   explicit join_view(R&&) -> join_view<views::all_t<R>>;
14 
15 // Tests that the deduction guide is explicit.
16 
17 #include <ranges>
18 
19 #include "test_iterators.h"
20 
21 template<class T>
22 struct Range {
begin(Range &)23   friend T* begin(Range&) { return nullptr; }
begin(Range const &)24   friend T* begin(Range const&) { return nullptr; }
end(Range &)25   friend sentinel_wrapper<T*> end(Range&) { return sentinel_wrapper<T*>(nullptr); }
end(Range const &)26   friend sentinel_wrapper<T*> end(Range const&) { return sentinel_wrapper<T*>(nullptr); }
27 };
28 
testExplicitCTAD()29 void testExplicitCTAD() {
30   Range<Range<int>> r;
31   std::ranges::join_view v = r; // expected-error {{no viable constructor or deduction guide for deduction of template arguments of 'join_view'}}
32 }
33