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 end() requires (!simple-view<V>) |
12 | // { return sentinel<false>(ranges::end(base_), addressof(*pred_)); } |
13 | // constexpr auto end() const |
14 | // requires range<const V> && |
15 | // indirect_unary_predicate<const Pred, iterator_t<const V>> |
16 | // { return sentinel<true>(ranges::end(base_), addressof(*pred_)); } |
17 | |
18 | #include <cassert> |
19 | #include <ranges> |
20 | #include <type_traits> |
21 | #include <utility> |
22 | |
23 | #include "types.h" |
24 | |
25 | // Test Constraints |
26 | template <class T> |
27 | concept HasConstEnd = requires(const T& ct) { ct.end(); }; |
28 | |
29 | template <class T> |
30 | concept HasEnd = requires(T& t) { t.end(); }; |
31 | |
32 | template <class T> |
33 | concept HasConstAndNonConstEnd = |
34 | HasConstEnd<T> && requires(T& t, const T& ct) { requires !std::same_as<decltype(t.end()), decltype(ct.end())>; }; |
35 | |
36 | template <class T> |
37 | concept HasOnlyNonConstEnd = HasEnd<T> && !HasConstEnd<T>; |
38 | |
39 | template <class T> |
40 | concept HasOnlyConstEnd = HasConstEnd<T> && !HasConstAndNonConstEnd<T>; |
41 | |
42 | struct Pred { |
43 | constexpr bool operator()(int i) const { return i < 5; } |
44 | }; |
45 | |
46 | static_assert(HasOnlyConstEnd<std::ranges::take_while_view<SimpleView, Pred>>); |
47 | |
48 | static_assert(HasOnlyNonConstEnd<std::ranges::take_while_view<ConstNotRange, Pred>>); |
49 | |
50 | static_assert(HasConstAndNonConstEnd<std::ranges::take_while_view<NonSimple, Pred>>); |
51 | |
52 | struct NotPredForConst { |
53 | constexpr bool operator()(int& i) const { return i > 5; } |
54 | }; |
55 | static_assert(HasOnlyNonConstEnd<std::ranges::take_while_view<NonSimple, NotPredForConst>>); |
56 | |
57 | constexpr bool test() { |
58 | // simple-view |
59 | { |
60 | int buffer[] = {1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1}; |
61 | SimpleView v{buffer}; |
62 | std::ranges::take_while_view twv(v, Pred{}); |
63 | decltype(auto) it1 = twv.end(); |
64 | assert(it1 == buffer + 4); |
65 | decltype(auto) it2 = std::as_const(twv).end(); |
66 | assert(it2 == buffer + 4); |
67 | |
68 | static_assert(std::same_as<decltype(it1), decltype(it2)>); |
69 | } |
70 | |
71 | // const not range |
72 | { |
73 | int buffer[] = {1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1}; |
74 | ConstNotRange v{buffer}; |
75 | std::ranges::take_while_view twv(v, Pred{}); |
76 | decltype(auto) it1 = twv.end(); |
77 | assert(it1 == buffer + 4); |
78 | } |
79 | |
80 | // NonSimple |
81 | { |
82 | int buffer[] = {1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1}; |
83 | NonSimple v{buffer}; |
84 | std::ranges::take_while_view twv(v, Pred{}); |
85 | decltype(auto) it1 = twv.end(); |
86 | assert(it1 == buffer + 4); |
87 | decltype(auto) it2 = std::as_const(twv).end(); |
88 | assert(it2 == buffer + 4); |
89 | |
90 | static_assert(!std::same_as<decltype(it1), decltype(it2)>); |
91 | } |
92 | |
93 | // NotPredForConst |
94 | // LWG 3450: The const overloads of `take_while_view::begin/end` are underconstrained |
95 | { |
96 | int buffer[] = {1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1}; |
97 | NonSimple v{buffer}; |
98 | std::ranges::take_while_view twv(v, NotPredForConst{}); |
99 | decltype(auto) it1 = twv.end(); |
100 | assert(it1 == buffer); |
101 | } |
102 | |
103 | return true; |
104 | } |
105 | |
106 | int main(int, char**) { |
107 | test(); |
108 | static_assert(test()); |
109 | return 0; |
110 | } |
111 | |