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 auto size()
12 // requires sized_range<V>
13 // constexpr auto size() const
14 // requires sized_range<const V>
15
16 #include <ranges>
17
18 #include "test_macros.h"
19 #include "types.h"
20
21 template<class T>
22 concept SizeInvocable = requires(std::ranges::drop_view<T> t) { t.size(); };
23
test()24 constexpr bool test() {
25 // sized_range<V>
26 std::ranges::drop_view dropView1(MoveOnlyView(), 4);
27 assert(dropView1.size() == 4);
28
29 // sized_range<V>
30 std::ranges::drop_view dropView2(MoveOnlyView(), 0);
31 assert(dropView2.size() == 8);
32
33 // sized_range<const V>
34 const std::ranges::drop_view dropView3(MoveOnlyView(), 8);
35 assert(dropView3.size() == 0);
36
37 // sized_range<const V>
38 const std::ranges::drop_view dropView4(MoveOnlyView(), 10);
39 assert(dropView4.size() == 0);
40
41 // Because ForwardView is not a sized_range.
42 static_assert(!SizeInvocable<ForwardView>);
43
44 return true;
45 }
46
main(int,char **)47 int main(int, char**) {
48 test();
49 static_assert(test());
50
51 return 0;
52 }
53