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 // friend constexpr iterator operator+(iterator i, difference_type n)
12 // requires advanceable<W>;
13 // friend constexpr iterator operator+(difference_type n, iterator i)
14 // requires advanceable<W>;
15
16 #include <cassert>
17 #include <ranges>
18 #include <type_traits>
19
20 #include "test_macros.h"
21 #include "../types.h"
22
test()23 constexpr bool test() {
24 // When "_Start" is signed integer like.
25 {
26 std::ranges::iota_view<int> io(0);
27 auto iter1 = io.begin();
28 auto iter2 = io.begin();
29 assert(iter1 == iter2);
30 assert(iter1 + 5 != iter2);
31 assert(iter1 + 5 == std::ranges::next(iter2, 5));
32
33 static_assert(std::is_reference_v<decltype(iter2 += 5)>);
34 }
35
36 // When "_Start" is not integer like.
37 {
38 std::ranges::iota_view io(SomeInt(0));
39 auto iter1 = io.begin();
40 auto iter2 = io.begin();
41 assert(iter1 == iter2);
42 assert(iter1 + 5 != iter2);
43 assert(iter1 + 5 == std::ranges::next(iter2, 5));
44
45 static_assert(std::is_reference_v<decltype(iter2 += 5)>);
46 }
47
48 // When "_Start" is unsigned integer like and n is greater than or equal to zero.
49 {
50 std::ranges::iota_view<unsigned> io(0);
51 auto iter1 = io.begin();
52 auto iter2 = io.begin();
53 assert(iter1 == iter2);
54 assert(iter1 + 5 != iter2);
55 assert(iter1 + 5 == std::ranges::next(iter2, 5));
56
57 static_assert(std::is_reference_v<decltype(iter2 += 5)>);
58 }
59 {
60 std::ranges::iota_view<unsigned> io(0);
61 auto iter1 = io.begin();
62 auto iter2 = io.begin();
63 assert(iter1 == iter2);
64 assert(iter1 + 0 == iter2);
65 }
66
67 // When "_Start" is unsigned integer like and n is less than zero.
68 {
69 std::ranges::iota_view<unsigned> io(0);
70 auto iter1 = io.begin();
71 auto iter2 = io.begin();
72 assert(iter1 == iter2);
73 assert(iter1 + 5 != iter2);
74 assert(iter1 + 5 == std::ranges::next(iter2, 5));
75
76 static_assert(std::is_reference_v<decltype(iter2 += 5)>);
77 }
78
79 return true;
80 }
81
main(int,char **)82 int main(int, char**) {
83 test();
84 static_assert(test());
85
86 return 0;
87 }
88