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// constexpr span() noexcept;
13
14#include <span>
15#include <cassert>
16#include <string>
17#include <type_traits>
18
19#include "test_macros.h"
20
21void checkCV()
22{
23// Types the same (dynamic sized)
24 {
25 std::span< int> s1;
26 std::span<const int> s2;
27 std::span< volatile int> s3;
28 std::span<const volatile int> s4;
29 assert(s1.size() + s2.size() + s3.size() + s4.size() == 0);
30 }
31
32// Types the same (static sized)
33 {
34 std::span< int,0> s1;
35 std::span<const int,0> s2;
36 std::span< volatile int,0> s3;
37 std::span<const volatile int,0> s4;
38 assert(s1.size() + s2.size() + s3.size() + s4.size() == 0);
39 }
40}
41
42
43template <typename T>
44constexpr bool testConstexprSpan()
45{
46 std::span<const T> s1;
47 std::span<const T, 0> s2;
48 return
49 s1.data() == nullptr && s1.size() == 0
50 && s2.data() == nullptr && s2.size() == 0;
51}
52
53
54template <typename T>
55void testRuntimeSpan()
56{
57 ASSERT_NOEXCEPT(T{});
58 std::span<const T> s1;
59 std::span<const T, 0> s2;
60 assert(s1.data() == nullptr && s1.size() == 0);
61 assert(s2.data() == nullptr && s2.size() == 0);
62}
63
64
65struct A{};
66
67int main(int, char**)
68{
69 static_assert(testConstexprSpan<int>(), "");
70 static_assert(testConstexprSpan<long>(), "");
71 static_assert(testConstexprSpan<double>(), "");
72 static_assert(testConstexprSpan<A>(), "");
73
74 testRuntimeSpan<int>();
75 testRuntimeSpan<long>();
76 testRuntimeSpan<double>();
77 testRuntimeSpan<std::string>();
78 testRuntimeSpan<A>();
79
80 checkCV();
81
82 static_assert( std::is_default_constructible_v<std::span<int, std::dynamic_extent>>, "");
83 static_assert( std::is_default_constructible_v<std::span<int, 0>>, "");
84 static_assert(!std::is_default_constructible_v<std::span<int, 2>>, "");
85
86 return 0;
87}
88

source code of libcxx/test/std/containers/views/views.span/span.cons/default.pass.cpp