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 explicit iota_view(W value);
12
13#include <cassert>
14#include <ranges>
15#include <type_traits>
16
17#include "test_macros.h"
18#include "types.h"
19
20struct SomeIntComparable {
21 using difference_type = int;
22
23 SomeInt value_;
24 constexpr SomeIntComparable() : value_(SomeInt(10)) {}
25
26 friend constexpr bool operator==(SomeIntComparable lhs, SomeIntComparable rhs) {
27 return lhs.value_ == rhs.value_;
28 }
29 friend constexpr bool operator==(SomeIntComparable lhs, SomeInt rhs) {
30 return lhs.value_ == rhs;
31 }
32 friend constexpr bool operator==(SomeInt lhs, SomeIntComparable rhs) {
33 return lhs == rhs.value_;
34 }
35
36 friend constexpr difference_type operator-(SomeIntComparable lhs, SomeIntComparable rhs) {
37 return lhs.value_ - rhs.value_;
38 }
39
40 constexpr SomeIntComparable& operator++() { ++value_; return *this; }
41 constexpr SomeIntComparable operator++(int) { auto tmp = *this; ++value_; return tmp; }
42 constexpr SomeIntComparable operator--() { --value_; return *this; }
43};
44
45constexpr bool test() {
46 {
47 std::ranges::iota_view<SomeInt> io(SomeInt(42));
48 assert((*io.begin()).value_ == 42);
49 // Check that end returns std::unreachable_sentinel.
50 assert(io.end() != io.begin());
51 static_assert(std::same_as<decltype(io.end()), std::unreachable_sentinel_t>);
52 }
53
54 {
55 std::ranges::iota_view<SomeInt, SomeIntComparable> io(SomeInt(0));
56 assert(std::ranges::next(io.begin(), 10) == io.end());
57 }
58 {
59 static_assert(!std::is_convertible_v<std::ranges::iota_view<SomeInt>, SomeInt>);
60 static_assert( std::is_constructible_v<std::ranges::iota_view<SomeInt>, SomeInt>);
61 }
62
63 return true;
64}
65
66int main(int, char**) {
67 test();
68 static_assert(test());
69
70 return 0;
71}
72

source code of libcxx/test/std/ranges/range.factories/range.iota.view/ctor.value.pass.cpp