1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
|
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17
// UNSUPPORTED: libcpp-has-no-incomplete-ranges
// constexpr auto size() const requires see below;
#include <ranges>
#include <cassert>
#include <limits>
#include "test_macros.h"
#include "types.h"
constexpr bool test() {
// Both are integer like and both are less than zero.
{
const std::ranges::iota_view<int, int> io(-10, -5);
assert(io.size() == 5);
}
{
const std::ranges::iota_view<int, int> io(-10, -10);
assert(io.size() == 0);
}
// Both are integer like and "value_" is less than zero.
{
const std::ranges::iota_view<int, int> io(-10, 10);
assert(io.size() == 20);
}
{
// TODO: this is invalid with the current implementation. We need to file an LWG issue to
// fix this. Essentially the issue is: An int's min and max are -2147483648 and 2147483647
// which means the negated min cannot be represented as an integer; it needs to be cast to
// an unsigned type first. That seems to be what the
// to-unsigned-like(bound_) + to-unsigned-like(-value_))
// part of https://eel.is/c++draft/range.iota#view-15 is doing, but I think it's doing it
// wrong. It should be to-unsigned-like(bound_) - to-unsigned-like(value_)) (cast to
// unsigned first).
// const std::ranges::iota_view<int, int> io(std::numeric_limits<int>::min(), std::numeric_limits<int>::max());
// assert(io.size() == (static_cast<unsigned>(std::numeric_limits<int>::max()) * 2) + 1);
}
// It is UB for "bound_" to be less than "value_" i.e.: iota_view<int, int> io(10, -5).
// Both are integer like and neither less than zero.
{
const std::ranges::iota_view<int, int> io(10, 20);
assert(io.size() == 10);
}
{
const std::ranges::iota_view<int, int> io(10, 10);
assert(io.size() == 0);
}
{
const std::ranges::iota_view<int, int> io(0, 0);
assert(io.size() == 0);
}
{
const std::ranges::iota_view<int, int> io(0, std::numeric_limits<int>::max());
constexpr auto imax = std::numeric_limits<int>::max();
assert(io.size() == imax);
}
// Neither are integer like.
{
const std::ranges::iota_view<SomeInt, SomeInt> io(SomeInt(-20), SomeInt(-10));
assert(io.size() == 10);
}
{
const std::ranges::iota_view<SomeInt, SomeInt> io(SomeInt(-10), SomeInt(-10));
assert(io.size() == 0);
}
{
const std::ranges::iota_view<SomeInt, SomeInt> io(SomeInt(0), SomeInt(0));
assert(io.size() == 0);
}
{
const std::ranges::iota_view<SomeInt, SomeInt> io(SomeInt(10), SomeInt(20));
assert(io.size() == 10);
}
{
const std::ranges::iota_view<SomeInt, SomeInt> io(SomeInt(10), SomeInt(10));
assert(io.size() == 0);
}
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
|
