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