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<size_t N>
13 // constexpr span(element_type (&arr)[N]) noexcept;
14 //
15 // Remarks: These constructors shall not participate in overload resolution unless:
16 // — extent == dynamic_extent || N == extent is true, and
17 // — remove_pointer_t<decltype(data(arr))>(*)[] is convertible to ElementType(*)[].
18 //
19
20
21 #include <span>
22 #include <cassert>
23 #include <string>
24
25 #include "test_macros.h"
26
27
checkCV()28 void checkCV()
29 {
30 int arr[] = {1,2,3};
31 const int carr[] = {4,5,6};
32 volatile int varr[] = {7,8,9};
33 const volatile int cvarr[] = {1,3,5};
34
35 // Types the same (dynamic sized)
36 {
37 std::span< int> s1{ arr}; // a span< int> pointing at int.
38 std::span<const int> s2{ carr}; // a span<const int> pointing at const int.
39 std::span< volatile int> s3{ varr}; // a span< volatile int> pointing at volatile int.
40 std::span<const volatile int> s4{cvarr}; // a span<const volatile int> pointing at const volatile int.
41 assert(s1.size() + s2.size() + s3.size() + s4.size() == 12);
42 }
43
44 // Types the same (static sized)
45 {
46 std::span< int,3> s1{ arr}; // a span< int> pointing at int.
47 std::span<const int,3> s2{ carr}; // a span<const int> pointing at const int.
48 std::span< volatile int,3> s3{ varr}; // a span< volatile int> pointing at volatile int.
49 std::span<const volatile int,3> s4{cvarr}; // a span<const volatile int> pointing at const volatile int.
50 assert(s1.size() + s2.size() + s3.size() + s4.size() == 12);
51 }
52
53
54 // types different (dynamic sized)
55 {
56 std::span<const int> s1{ arr}; // a span<const int> pointing at int.
57 std::span< volatile int> s2{ arr}; // a span< volatile int> pointing at int.
58 std::span< volatile int> s3{ arr}; // a span< volatile int> pointing at const int.
59 std::span<const volatile int> s4{ arr}; // a span<const volatile int> pointing at int.
60 std::span<const volatile int> s5{carr}; // a span<const volatile int> pointing at const int.
61 std::span<const volatile int> s6{varr}; // a span<const volatile int> pointing at volatile int.
62 assert(s1.size() + s2.size() + s3.size() + s4.size() + s5.size() + s6.size() == 18);
63 }
64
65 // types different (static sized)
66 {
67 std::span<const int,3> s1{ arr}; // a span<const int> pointing at int.
68 std::span< volatile int,3> s2{ arr}; // a span< volatile int> pointing at int.
69 std::span< volatile int,3> s3{ arr}; // a span< volatile int> pointing at const int.
70 std::span<const volatile int,3> s4{ arr}; // a span<const volatile int> pointing at int.
71 std::span<const volatile int,3> s5{carr}; // a span<const volatile int> pointing at const int.
72 std::span<const volatile int,3> s6{varr}; // a span<const volatile int> pointing at volatile int.
73 assert(s1.size() + s2.size() + s3.size() + s4.size() + s5.size() + s6.size() == 18);
74 }
75 }
76
77 template<class T>
testSpan()78 constexpr bool testSpan()
79 {
80 T val[2] = {};
81
82 ASSERT_NOEXCEPT(std::span<T>{val});
83 ASSERT_NOEXCEPT(std::span<T, 2>{val});
84 ASSERT_NOEXCEPT(std::span<const T>{val});
85 ASSERT_NOEXCEPT(std::span<const T, 2>{val});
86
87 std::span<T> s1 = val;
88 std::span<T, 2> s2 = val;
89 std::span<const T> s3 = val;
90 std::span<const T, 2> s4 = val;
91 assert(s1.data() == val && s1.size() == 2);
92 assert(s2.data() == val && s2.size() == 2);
93 assert(s3.data() == val && s3.size() == 2);
94 assert(s4.data() == val && s4.size() == 2);
95
96 std::span<const int> s5 = {{1,2}};
97 std::span<const int, 2> s6 = {{1,2}};
98 assert(s5.size() == 2); // and it dangles
99 assert(s6.size() == 2); // and it dangles
100
101 return true;
102 }
103
104
105 struct A {};
106
main(int,char **)107 int main(int, char**)
108 {
109 testSpan<int>();
110 testSpan<double>();
111 testSpan<A>();
112 testSpan<std::string>();
113
114 static_assert(testSpan<int>());
115 static_assert(testSpan<double>());
116 static_assert(testSpan<A>());
117
118 checkCV();
119
120 return 0;
121 }
122