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 const iterator_t<Base>& inner-iterator::base() const& noexcept;
12 //
13 // constexpr iterator_t<Base> inner-iterator::base() &&
14 // requires forward_range<View>;
15
16 #include <ranges>
17
18 #include <concepts>
19 #include <utility>
20 #include "../types.h"
21
22 static_assert( noexcept(std::declval<InnerIterForward&>().base()));
23 static_assert( noexcept(std::declval<InnerIterForward const &>().base()));
24 static_assert( noexcept(std::declval<InnerIterForward const &&>().base()));
25 static_assert( noexcept(std::declval<InnerIterInput&>().base()));
26 static_assert( noexcept(std::declval<InnerIterInput const &>().base()));
27 static_assert( noexcept(std::declval<InnerIterInput const &&>().base()));
28
test()29 constexpr bool test() {
30 // `base` works with a forward view (two different overloads based on ref-qualification of the `inner-iterator`).
31 {
32 using BaseIter = std::ranges::iterator_t<CopyableView>;
33 CopyableView input("abc def");
34 std::ranges::lazy_split_view<CopyableView, ForwardView> v(input, " ");
35 auto i = (*v.begin()).begin();
36 const auto ci = i;
37
38 // Note: some macOS platforms seem to have trouble deducing the type when using `std::same_as` -- use the equivalent
39 // `ASSERT_SAME_TYPE` instead.
40 {
41 decltype(auto) b = i.base();
42 ASSERT_SAME_TYPE(decltype(b), const BaseIter&);
43 assert(b == input.begin());
44 }
45
46 {
47 decltype(auto) b = ci.base();
48 ASSERT_SAME_TYPE(decltype(b), const BaseIter&);
49 assert(b == input.begin());
50 }
51
52 {
53 decltype(auto) b = std::move(i).base();
54 ASSERT_SAME_TYPE(decltype(b), BaseIter);
55 assert(b == input.begin());
56 }
57
58 {
59 decltype(auto) b = std::move(ci).base();
60 ASSERT_SAME_TYPE(decltype(b), const BaseIter&);
61 assert(b == input.begin());
62 }
63 }
64
65 // `base` works with an input view (no overloads).
66 {
67 using BaseIter = std::ranges::iterator_t<InputView>;
68 InputView input("abc def");
69 std::ranges::lazy_split_view<InputView, ForwardTinyView> v(input, ' ');
70 auto i = (*v.begin()).begin();
71 const auto ci = i;
72
73 {
74 decltype(auto) b = i.base();
75 ASSERT_SAME_TYPE(decltype(b), const BaseIter&);
76 }
77
78 {
79 decltype(auto) b = ci.base();
80 ASSERT_SAME_TYPE(decltype(b), const BaseIter&);
81 }
82
83 {
84 decltype(auto) b = std::move(i).base();
85 ASSERT_SAME_TYPE(decltype(b), const BaseIter&);
86 }
87
88 {
89 decltype(auto) b = std::move(ci).base();
90 ASSERT_SAME_TYPE(decltype(b), const BaseIter&);
91 }
92 }
93
94 return true;
95 }
96
main(int,char **)97 int main(int, char**) {
98 test();
99 static_assert(test());
100
101 return 0;
102 }
103