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
|
//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
// <iterator>
// template <InputIterator Iter>
// Iter::difference_type
// distance(Iter first, Iter last); // constexpr in C++17
//
// template <RandomAccessIterator Iter>
// Iter::difference_type
// distance(Iter first, Iter last); // constexpr in C++17
#include <iterator>
#include <cassert>
#include <type_traits>
#include "test_macros.h"
#include "test_iterators.h"
template <class It>
TEST_CONSTEXPR_CXX17
void check_distance(It first, It last, typename std::iterator_traits<It>::difference_type dist)
{
typedef typename std::iterator_traits<It>::difference_type Difference;
static_assert(std::is_same<decltype(std::distance(first, last)), Difference>::value, "");
assert(std::distance(first, last) == dist);
}
TEST_CONSTEXPR_CXX17 bool tests()
{
const char* s = "1234567890";
check_distance(cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10), 10);
check_distance(forward_iterator<const char*>(s), forward_iterator<const char*>(s+10), 10);
check_distance(bidirectional_iterator<const char*>(s), bidirectional_iterator<const char*>(s+10), 10);
check_distance(random_access_iterator<const char*>(s), random_access_iterator<const char*>(s+10), 10);
check_distance(s, s+10, 10);
return true;
}
int main(int, char**)
{
tests();
#if TEST_STD_VER >= 17
static_assert(tests(), "");
#endif
return 0;
}
|
