xref: /llvm-project/libcxx/test/std/ranges/range.adaptors/range.join/ctor.default.pass.cpp (revision 6a664674990094c1b5d2e717256f08cb04485899)
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 // join_view() requires default_initializable<V> = default;
12 
13 #include <cassert>
14 #include <ranges>
15 
16 #include "types.h"
17 
18 struct DefaultView : std::ranges::view_base {
19   int i; // deliberately uninitialised
20 
21   ChildView* begin() const;
22   ChildView* end() const;
23 };
24 
test()25 constexpr bool test() {
26   {
27     std::ranges::join_view<ParentView<ChildView>> jv;
28     assert(std::move(jv).base().ptr_ == globalChildren);
29   }
30 
31   // Default constructor should value initialise underlying view
32   {
33     std::ranges::join_view<DefaultView> jv;
34     assert(jv.base().i == 0);
35   }
36 
37   static_assert( std::default_initializable<std::ranges::join_view<ParentView<ChildView>>>);
38   static_assert(!std::default_initializable<std::ranges::join_view<CopyableParent>>);
39 
40   return true;
41 }
42 
main(int,char **)43 int main(int, char**) {
44   test();
45   static_assert(test());
46 
47   return 0;
48 }
49