1 //===----------------------------------------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
10
11 // <span>
12
13 // constexpr iterator end() const noexcept;
14 // constexpr const_iterator cend() const noexcept;
15
16 #include <span>
17 #include <cassert>
18 #include <string>
19
20 #include "test_macros.h"
21
22 template <class Span>
testConstexprSpan(Span s)23 constexpr bool testConstexprSpan(Span s)
24 {
25 bool ret = true;
26 typename Span::iterator e = s. end();
27 typename Span::const_iterator ce = s.cend();
28 if (s.empty())
29 {
30 ret = ret && ( e == s.begin());
31 ret = ret && (ce == s.cbegin());
32 }
33 else
34 {
35 typename Span::const_pointer last = &*(s.cbegin() + s.size() - 1);
36 ret = ret && ( e != s.begin());
37 ret = ret && (ce != s.cbegin());
38 ret = ret && (&*( e-1) == last);
39 ret = ret && (&*(ce-1) == last);
40 }
41
42 ret = ret && (( e - s.begin()) == s.size());
43 ret = ret && ((ce - s.cbegin()) == s.size());
44
45 ret = ret && (e == ce);
46 return ret;
47 }
48
49 template <class Span>
testRuntimeSpan(Span s)50 void testRuntimeSpan(Span s)
51 {
52 typename Span::iterator e = s. end();
53 typename Span::const_iterator ce = s.cend();
54 if (s.empty())
55 {
56 assert( e == s.begin());
57 assert(ce == s.cbegin());
58 }
59 else
60 {
61 typename Span::const_pointer last = &*(s.cbegin() + s.size() - 1);
62 assert( e != s.begin());
63 assert(ce != s.cbegin());
64 assert( &*( e-1) == last);
65 assert( &*(ce-1) == last);
66 }
67
68 assert(( e - s.begin()) == s.size());
69 assert((ce - s.cbegin()) == s.size());
70
71 assert(e == ce);
72 }
73
74
75 struct A{};
operator ==(A,A)76 bool operator==(A, A) {return true;}
77
78 constexpr int iArr1[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
79 int iArr2[] = {10, 11, 12, 13, 14, 15, 16, 17, 18, 19};
80
81
main()82 int main()
83 {
84 static_assert(testConstexprSpan(std::span<int>()), "");
85 static_assert(testConstexprSpan(std::span<long>()), "");
86 static_assert(testConstexprSpan(std::span<double>()), "");
87 static_assert(testConstexprSpan(std::span<A>()), "");
88 static_assert(testConstexprSpan(std::span<std::string>()), "");
89
90 static_assert(testConstexprSpan(std::span<int, 0>()), "");
91 static_assert(testConstexprSpan(std::span<long, 0>()), "");
92 static_assert(testConstexprSpan(std::span<double, 0>()), "");
93 static_assert(testConstexprSpan(std::span<A, 0>()), "");
94 static_assert(testConstexprSpan(std::span<std::string, 0>()), "");
95
96 static_assert(testConstexprSpan(std::span<const int>(iArr1, 1)), "");
97 static_assert(testConstexprSpan(std::span<const int>(iArr1, 2)), "");
98 static_assert(testConstexprSpan(std::span<const int>(iArr1, 3)), "");
99 static_assert(testConstexprSpan(std::span<const int>(iArr1, 4)), "");
100 static_assert(testConstexprSpan(std::span<const int>(iArr1, 5)), "");
101
102
103 testRuntimeSpan(std::span<int> ());
104 testRuntimeSpan(std::span<long> ());
105 testRuntimeSpan(std::span<double> ());
106 testRuntimeSpan(std::span<A> ());
107 testRuntimeSpan(std::span<std::string>());
108
109 testRuntimeSpan(std::span<int, 0> ());
110 testRuntimeSpan(std::span<long, 0> ());
111 testRuntimeSpan(std::span<double, 0> ());
112 testRuntimeSpan(std::span<A, 0> ());
113 testRuntimeSpan(std::span<std::string, 0>());
114
115 testRuntimeSpan(std::span<int>(iArr2, 1));
116 testRuntimeSpan(std::span<int>(iArr2, 2));
117 testRuntimeSpan(std::span<int>(iArr2, 3));
118 testRuntimeSpan(std::span<int>(iArr2, 4));
119 testRuntimeSpan(std::span<int>(iArr2, 5));
120
121 std::string s;
122 testRuntimeSpan(std::span<std::string>(&s, (std::ptrdiff_t) 0));
123 testRuntimeSpan(std::span<std::string>(&s, 1));
124 }
125