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 | // template<class I2> |
12 | // requires convertible_to<const I2&, I> |
13 | // constexpr counted_iterator(const counted_iterator<I2>& x); |
14 | |
15 | #include <iterator> |
16 | |
17 | #include "test_macros.h" |
18 | #include "test_iterators.h" |
19 | |
20 | template<class T> |
21 | class ConvertibleTo |
22 | { |
23 | int *it_; |
24 | |
25 | public: |
26 | typedef std::input_iterator_tag iterator_category; |
27 | typedef int value_type; |
28 | typedef typename std::iterator_traits<int *>::difference_type difference_type; |
29 | typedef int * pointer; |
30 | typedef int & reference; |
31 | |
32 | constexpr int *base() const {return it_;} |
33 | |
34 | ConvertibleTo() = default; |
35 | explicit constexpr ConvertibleTo(int *it) : it_(it) {} |
36 | |
37 | constexpr reference operator*() const {return *it_;} |
38 | |
39 | constexpr ConvertibleTo& operator++() {++it_; return *this;} |
40 | constexpr ConvertibleTo operator++(int) |
41 | {ConvertibleTo tmp(*this); ++(*this); return tmp;} |
42 | |
43 | constexpr operator T() const { return T(it_); } |
44 | }; |
45 | |
46 | constexpr bool test() { |
47 | int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8}; |
48 | |
49 | { |
50 | static_assert( std::is_constructible_v<std::counted_iterator<forward_iterator<int*>>, |
51 | std::counted_iterator<forward_iterator<int*>>>); |
52 | static_assert(!std::is_constructible_v<std::counted_iterator<forward_iterator<int*>>, |
53 | std::counted_iterator<random_access_iterator<int*>>>); |
54 | } |
55 | { |
56 | std::counted_iterator iter1(ConvertibleTo<forward_iterator<int*>>{buffer}, 8); |
57 | std::counted_iterator<forward_iterator<int*>> iter2(iter1); |
58 | assert(iter2.base() == forward_iterator<int*>{buffer}); |
59 | assert(iter2.count() == 8); |
60 | } |
61 | { |
62 | const std::counted_iterator iter1(ConvertibleTo<forward_iterator<int*>>{buffer}, 8); |
63 | const std::counted_iterator<forward_iterator<int*>> iter2(iter1); |
64 | assert(iter2.base() == forward_iterator<int*>{buffer}); |
65 | assert(iter2.count() == 8); |
66 | } |
67 | |
68 | return true; |
69 | } |
70 | |
71 | int main(int, char**) { |
72 | test(); |
73 | static_assert(test()); |
74 | |
75 | return 0; |
76 | } |
77 | |