xref: /llvm-project/libcxx/test/std/containers/views/views.span/span.obs/size.pass.cpp (revision fb855eb941b6d740cc6560297d0b4d3201dcaf9f)
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 size_type size() const noexcept;
13 //
14 
15 
16 #include <span>
17 #include <cassert>
18 #include <string>
19 
20 #include "test_macros.h"
21 
22 
23 template <typename Span>
testConstexprSpan(Span sp,std::size_t sz)24 constexpr bool testConstexprSpan(Span sp, std::size_t sz)
25 {
26     ASSERT_NOEXCEPT(sp.size());
27     return sp.size() == sz;
28 }
29 
30 
31 template <typename Span>
testRuntimeSpan(Span sp,std::size_t sz)32 void testRuntimeSpan(Span sp, std::size_t sz)
33 {
34     ASSERT_NOEXCEPT(sp.size());
35     assert(sp.size() == sz);
36 }
37 
38 struct A{};
39 constexpr int iArr1[] = { 0,  1,  2,  3,  4,  5,  6,  7,  8,  9};
40           int iArr2[] = {10, 11, 12, 13, 14, 15, 16, 17, 18, 19};
41 
main(int,char **)42 int main(int, char**)
43 {
44     static_assert(testConstexprSpan(std::span<int>(), 0),            "");
45     static_assert(testConstexprSpan(std::span<long>(), 0),           "");
46     static_assert(testConstexprSpan(std::span<double>(), 0),         "");
47     static_assert(testConstexprSpan(std::span<A>(), 0),              "");
48     static_assert(testConstexprSpan(std::span<std::string>(), 0),    "");
49 
50     static_assert(testConstexprSpan(std::span<int, 0>(), 0),         "");
51     static_assert(testConstexprSpan(std::span<long, 0>(), 0),        "");
52     static_assert(testConstexprSpan(std::span<double, 0>(), 0),      "");
53     static_assert(testConstexprSpan(std::span<A, 0>(), 0),           "");
54     static_assert(testConstexprSpan(std::span<std::string, 0>(), 0), "");
55 
56     static_assert(testConstexprSpan(std::span<const int>(iArr1, 1), 1),    "");
57     static_assert(testConstexprSpan(std::span<const int>(iArr1, 2), 2),    "");
58     static_assert(testConstexprSpan(std::span<const int>(iArr1, 3), 3),    "");
59     static_assert(testConstexprSpan(std::span<const int>(iArr1, 4), 4),    "");
60     static_assert(testConstexprSpan(std::span<const int>(iArr1, 5), 5),    "");
61 
62     testRuntimeSpan(std::span<int>        (), 0);
63     testRuntimeSpan(std::span<long>       (), 0);
64     testRuntimeSpan(std::span<double>     (), 0);
65     testRuntimeSpan(std::span<A>          (), 0);
66     testRuntimeSpan(std::span<std::string>(), 0);
67 
68     testRuntimeSpan(std::span<int, 0>        (), 0);
69     testRuntimeSpan(std::span<long, 0>       (), 0);
70     testRuntimeSpan(std::span<double, 0>     (), 0);
71     testRuntimeSpan(std::span<A, 0>          (), 0);
72     testRuntimeSpan(std::span<std::string, 0>(), 0);
73 
74     testRuntimeSpan(std::span<int>(iArr2, 1), 1);
75     testRuntimeSpan(std::span<int>(iArr2, 2), 2);
76     testRuntimeSpan(std::span<int>(iArr2, 3), 3);
77     testRuntimeSpan(std::span<int>(iArr2, 4), 4);
78     testRuntimeSpan(std::span<int>(iArr2, 5), 5);
79 
80     testRuntimeSpan(std::span<int, 1>(iArr2 + 5, 1), 1);
81     testRuntimeSpan(std::span<int, 2>(iArr2 + 4, 2), 2);
82     testRuntimeSpan(std::span<int, 3>(iArr2 + 3, 3), 3);
83     testRuntimeSpan(std::span<int, 4>(iArr2 + 2, 4), 4);
84     testRuntimeSpan(std::span<int, 5>(iArr2 + 1, 5), 5);
85 
86     std::string s;
87     testRuntimeSpan(std::span<std::string>(&s, (std::size_t) 0), 0);
88     testRuntimeSpan(std::span<std::string>(&s, 1), 1);
89 
90   return 0;
91 }
92