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 // UNSUPPORTED: c++03, c++11, c++14, c++17
9
10 // <span>
11
12 // template<class R>
13 // constexpr explicit(Extent != dynamic_extent) span(R&& r);
14
15
16 #include <span>
17 #include <cassert>
18 #include <ranges>
19 #include <string_view>
20 #include <type_traits>
21 #include <vector>
22
23 #include "test_iterators.h"
24
25 template <class T, std::size_t Extent>
test_from_range()26 constexpr void test_from_range() {
27 T val[3]{};
28 std::span<T, Extent> s{val};
29 assert(s.size() == std::size(val));
30 assert(s.data() == std::data(val));
31 }
32
33 struct A {};
34
test()35 constexpr bool test() {
36 test_from_range<int, std::dynamic_extent>();
37 test_from_range<int, 3>();
38 test_from_range<A, std::dynamic_extent>();
39 test_from_range<A, 3>();
40 return true;
41 }
42
43 static_assert(!std::is_constructible_v<std::span<int>, std::vector<float>&>); // wrong type
44 static_assert(!std::is_constructible_v<std::span<int, 3>, std::vector<float>&>); // wrong type
45
46 static_assert(std::is_constructible_v<std::span<int>, std::vector<int>&>); // non-borrowed lvalue
47 static_assert(std::is_constructible_v<std::span<int, 3>, std::vector<int>&>); // non-borrowed lvalue
48 static_assert(std::is_constructible_v<std::span<const int>, std::vector<int>&>); // non-borrowed lvalue
49 static_assert(std::is_constructible_v<std::span<const int, 3>, std::vector<int>&>); // non-borrowed lvalue
50 static_assert(!std::is_constructible_v<std::span<int>, const std::vector<int>&>); // non-borrowed const lvalue
51 static_assert(!std::is_constructible_v<std::span<int, 3>, const std::vector<int>&>); // non-borrowed const lvalue
52 static_assert(std::is_constructible_v<std::span<const int>, const std::vector<int>&>); // non-borrowed const lvalue
53 static_assert(std::is_constructible_v<std::span<const int, 3>, const std::vector<int>&>); // non-borrowed const lvalue
54 static_assert(std::is_constructible_v<std::span<const int>, std::vector<int>>); // non-borrowed rvalue
55 static_assert(std::is_constructible_v<std::span<const int, 3>, std::vector<int>>); // non-borrowed rvalue
56 static_assert(!std::is_constructible_v<std::span<int>, std::vector<int>&&>); // non-borrowed rvalue
57 static_assert(!std::is_constructible_v<std::span<int, 3>, std::vector<int>&&>); // non-borrowed rvalue
58
59 static_assert(std::is_constructible_v<std::span<int>, std::ranges::subrange<contiguous_iterator<int*>>>); // contiguous borrowed rvalue
60 static_assert(std::is_constructible_v<std::span<int, 3>, std::ranges::subrange<contiguous_iterator<int*>>>); // contiguous borrowed rvalue
61 static_assert(!std::is_constructible_v<std::span<int>, std::ranges::subrange<random_access_iterator<int*>>>); // non-contiguous borrowed rvalue
62 static_assert(!std::is_constructible_v<std::span<int, 3>, std::ranges::subrange<random_access_iterator<int*>>>); // non-contiguous borrowed rvalue
63
64 using BorrowedContiguousSizedRange = std::string_view;
65 static_assert(std::is_constructible_v<std::span<const char>, BorrowedContiguousSizedRange>);
66 static_assert(std::is_constructible_v<std::span<const char, 3>, BorrowedContiguousSizedRange>);
67 static_assert(!std::is_constructible_v<std::span<char>, BorrowedContiguousSizedRange>);
68 static_assert(!std::is_constructible_v<std::span<char, 3>, BorrowedContiguousSizedRange>);
69
70 static_assert(std::is_convertible_v<BorrowedContiguousSizedRange&, std::span<const char>>);
71 static_assert(!std::is_convertible_v<BorrowedContiguousSizedRange&, std::span<const char, 3>>);
72 static_assert(!std::is_convertible_v<BorrowedContiguousSizedRange&, std::span<char>>);
73 static_assert(!std::is_convertible_v<BorrowedContiguousSizedRange&, std::span<char, 3>>);
74 static_assert(std::is_convertible_v<const BorrowedContiguousSizedRange&, std::span<const char>>);
75 static_assert(!std::is_convertible_v<const BorrowedContiguousSizedRange&, std::span<const char, 3>>);
76
main(int,char **)77 int main(int, char**) {
78 test();
79 static_assert(test());
80
81 return 0;
82 }
83