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 // iterator() requires default_initializable<iterator_t<Base>> = default;
12
13 #include <ranges>
14 #include <tuple>
15
16 #include "../types.h"
17
18 struct PODIter : IterBase<PODIter> {
19 int i; // deliberately uninitialised
20 };
21
22 struct IterDefaultCtrView : std::ranges::view_base {
23 PODIter begin() const;
24 PODIter end() const;
25 };
26
27 struct IterNoDefaultCtrView : std::ranges::view_base {
28 cpp20_input_iterator<std::tuple<int>*> begin() const;
29 sentinel_wrapper<cpp20_input_iterator<std::tuple<int>*>> end() const;
30 };
31
32 template <class View, std::size_t N>
33 using ElementsIter = std::ranges::iterator_t<std::ranges::elements_view<View, N>>;
34
35 static_assert(!std::default_initializable<ElementsIter<IterNoDefaultCtrView, 0>>);
36 static_assert(std::default_initializable<ElementsIter<IterDefaultCtrView, 0>>);
37
test()38 constexpr bool test() {
39 using Iter = ElementsIter<IterDefaultCtrView, 0>;
40 {
41 Iter iter;
42 assert(iter.base().i == 0); // PODIter has to be initialised to have value 0
43 }
44
45 {
46 Iter iter = {};
47 assert(iter.base().i == 0); // PODIter has to be initialised to have value 0
48 }
49
50 return true;
51 }
52
main(int,char **)53 int main(int, char**) {
54 test();
55 static_assert(test());
56
57 return 0;
58 }
59