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 V base() const & requires copy_constructible<V> { return base_; }
12 // constexpr V base() && { return std::move(base_); }
13
14 #include <cassert>
15 #include <ranges>
16 #include <type_traits>
17 #include <utility>
18
19 #include "MoveOnly.h"
20 #include "types.h"
21
22 struct View : std::ranges::view_interface<View> {
23 int i;
24 int* begin() const;
25 int* end() const;
26 };
27
28 struct MoveOnlyView : View {
29 MoveOnly mo;
30 };
31
32 template <class T>
33 concept HasBase = requires(T&& t) { std::forward<T>(t).base(); };
34
35 struct Pred {
operator ()Pred36 constexpr bool operator()(int i) const { return i > 5; }
37 };
38
39 static_assert(HasBase<std::ranges::take_while_view<View, Pred> const&>);
40 static_assert(HasBase<std::ranges::take_while_view<View, Pred>&&>);
41
42 static_assert(!HasBase<std::ranges::take_while_view<MoveOnlyView, Pred> const&>);
43 static_assert(HasBase<std::ranges::take_while_view<MoveOnlyView, Pred>&&>);
44
test()45 constexpr bool test() {
46 // const &
47 {
48 const std::ranges::take_while_view<View, Pred> twv{View{{}, 5}, {}};
49 std::same_as<View> decltype(auto) v = twv.base();
50 assert(v.i == 5);
51 }
52
53 // &
54 {
55 std::ranges::take_while_view<View, Pred> twv{View{{}, 5}, {}};
56 std::same_as<View> decltype(auto) v = twv.base();
57 assert(v.i == 5);
58 }
59
60 // &&
61 {
62 std::ranges::take_while_view<View, Pred> twv{View{{}, 5}, {}};
63 std::same_as<View> decltype(auto) v = std::move(twv).base();
64 assert(v.i == 5);
65 }
66
67 // const &&
68 {
69 const std::ranges::take_while_view<View, Pred> twv{View{{}, 5}, {}};
70 std::same_as<View> decltype(auto) v = std::move(twv).base();
71 assert(v.i == 5);
72 }
73
74 // move only
75 {
76 std::ranges::take_while_view<MoveOnlyView, Pred> twv{MoveOnlyView{{}, 5}, {}};
77 std::same_as<MoveOnlyView> decltype(auto) v = std::move(twv).base();
78 assert(v.mo.get() == 5);
79 }
80 return true;
81 }
82
main(int,char **)83 int main(int, char**) {
84 test();
85 static_assert(test());
86 return 0;
87 }
88