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, c++20
10
11// constexpr auto operator*() const;
12
13#include <array>
14#include <cassert>
15#include <ranges>
16#include <tuple>
17
18#include "../types.h"
19
20constexpr bool test() {
21 std::array a{1, 2, 3, 4};
22 std::array b{4.1, 3.2, 4.3};
23 {
24 // single range
25 std::ranges::zip_view v(a);
26 auto it = v.begin();
27 assert(&(std::get<0>(*it)) == &(a[0]));
28 static_assert(std::is_same_v<decltype(*it), std::tuple<int&>>);
29 }
30
31 {
32 // operator* is const
33 std::ranges::zip_view v(a);
34 const auto it = v.begin();
35 assert(&(std::get<0>(*it)) == &(a[0]));
36 }
37
38 {
39 // two ranges with different types
40 std::ranges::zip_view v(a, b);
41 auto it = v.begin();
42 auto [x, y] = *it;
43 assert(&x == &(a[0]));
44 assert(&y == &(b[0]));
45 static_assert(std::is_same_v<decltype(*it), std::tuple<int&, double&>>);
46
47 x = 5;
48 y = 0.1;
49 assert(a[0] == 5);
50 assert(b[0] == 0.1);
51 }
52
53 {
54 // underlying range with prvalue range_reference_t
55 std::ranges::zip_view v(a, b, std::views::iota(0, 5));
56 auto it = v.begin();
57 assert(&(std::get<0>(*it)) == &(a[0]));
58 assert(&(std::get<1>(*it)) == &(b[0]));
59 assert(std::get<2>(*it) == 0);
60 static_assert(std::is_same_v<decltype(*it), std::tuple<int&, double&, int>>);
61 }
62
63 {
64 // const-correctness
65 std::ranges::zip_view v(a, std::as_const(a));
66 auto it = v.begin();
67 assert(&(std::get<0>(*it)) == &(a[0]));
68 assert(&(std::get<1>(*it)) == &(a[0]));
69 static_assert(std::is_same_v<decltype(*it), std::tuple<int&, int const&>>);
70 }
71 return true;
72}
73
74int main(int, char**) {
75 test();
76 static_assert(test());
77
78 return 0;
79}
80

source code of libcxx/test/std/ranges/range.adaptors/range.zip/iterator/deref.pass.cpp