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 ElementType, size_t Extent>
13// span<const byte,
14// Extent == dynamic_extent
15// ? dynamic_extent
16// : sizeof(ElementType) * Extent>
17// as_bytes(span<ElementType, Extent> s) noexcept;
18
19#include <cassert>
20#include <cstddef>
21#include <span>
22#include <string>
23
24#include "test_macros.h"
25
26template <typename Span>
27void testRuntimeSpan(Span sp) {
28 ASSERT_NOEXCEPT(std::as_bytes(sp));
29
30 auto spBytes = std::as_bytes(sp);
31 using SB = decltype(spBytes);
32 ASSERT_SAME_TYPE(const std::byte, typename SB::element_type);
33
34 if constexpr (sp.extent == std::dynamic_extent)
35 assert(spBytes.extent == std::dynamic_extent);
36 else
37 assert(spBytes.extent == sizeof(typename Span::element_type) * sp.extent);
38
39 assert((void*)spBytes.data() == (void*)sp.data());
40 assert(spBytes.size() == sp.size_bytes());
41}
42
43struct A {};
44int iArr2[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
45
46int main(int, char**) {
47 testRuntimeSpan(std::span<int>());
48 testRuntimeSpan(std::span<long>());
49 testRuntimeSpan(std::span<double>());
50 testRuntimeSpan(std::span<A>());
51 testRuntimeSpan(std::span<std::string>());
52
53 testRuntimeSpan(std::span<int, 0>());
54 testRuntimeSpan(std::span<long, 0>());
55 testRuntimeSpan(std::span<double, 0>());
56 testRuntimeSpan(std::span<A, 0>());
57 testRuntimeSpan(std::span<std::string, 0>());
58
59 testRuntimeSpan(std::span<int>(iArr2, 1));
60 testRuntimeSpan(std::span<int>(iArr2, 2));
61 testRuntimeSpan(std::span<int>(iArr2, 3));
62 testRuntimeSpan(std::span<int>(iArr2, 4));
63 testRuntimeSpan(std::span<int>(iArr2, 5));
64
65 testRuntimeSpan(std::span<int, 1>(iArr2 + 5, 1));
66 testRuntimeSpan(std::span<int, 2>(iArr2 + 4, 2));
67 testRuntimeSpan(std::span<int, 3>(iArr2 + 3, 3));
68 testRuntimeSpan(std::span<int, 4>(iArr2 + 2, 4));
69 testRuntimeSpan(std::span<int, 5>(iArr2 + 1, 5));
70
71 std::string s;
72 testRuntimeSpan(std::span<std::string>(&s, (std::size_t)0));
73 testRuntimeSpan(std::span<std::string>(&s, 1));
74
75 return 0;
76}
77

source code of libcxx/test/std/containers/views/views.span/span.objectrep/as_bytes.pass.cpp