1 // -*- C++ -*-
2 //===------------------------------ span ---------------------------------===//
3 //
4 // The LLVM Compiler Infrastructure
5 //
6 // This file is dual licensed under the MIT and the University of Illinois Open
7 // Source Licenses. See LICENSE.TXT for details.
8 //
9 //===---------------------------------------------------------------------===//
10 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
11
12 // <span>
13
14 // template<ptrdiff_t Count>
15 // constexpr span<element_type, Count> last() const;
16 //
17 // constexpr span<element_type, dynamic_extent> last(index_type count) const;
18 //
19 // Requires: 0 <= Count && Count <= size().
20
21
22 #include <span>
23 #include <cassert>
24 #include <algorithm>
25 #include <string>
26
27 #include "test_macros.h"
28
29 template <typename Span, ptrdiff_t Count>
testConstexprSpan(Span sp)30 constexpr bool testConstexprSpan(Span sp)
31 {
32 LIBCPP_ASSERT((noexcept(sp.template last<Count>())));
33 LIBCPP_ASSERT((noexcept(sp.last(Count))));
34 auto s1 = sp.template last<Count>();
35 auto s2 = sp.last(Count);
36 using S1 = decltype(s1);
37 using S2 = decltype(s2);
38 ASSERT_SAME_TYPE(typename Span::value_type, typename S1::value_type);
39 ASSERT_SAME_TYPE(typename Span::value_type, typename S2::value_type);
40 static_assert(S1::extent == Count, "");
41 static_assert(S2::extent == std::dynamic_extent, "");
42 return
43 s1.data() == s2.data()
44 && s1.size() == s2.size()
45 && std::equal(s1.begin(), s1.end(), sp.end() - Count);
46 }
47
48
49 template <typename Span, ptrdiff_t Count>
testRuntimeSpan(Span sp)50 void testRuntimeSpan(Span sp)
51 {
52 LIBCPP_ASSERT((noexcept(sp.template last<Count>())));
53 LIBCPP_ASSERT((noexcept(sp.last(Count))));
54 auto s1 = sp.template last<Count>();
55 auto s2 = sp.last(Count);
56 using S1 = decltype(s1);
57 using S2 = decltype(s2);
58 ASSERT_SAME_TYPE(typename Span::value_type, typename S1::value_type);
59 ASSERT_SAME_TYPE(typename Span::value_type, typename S2::value_type);
60 static_assert(S1::extent == Count, "");
61 static_assert(S2::extent == std::dynamic_extent, "");
62 assert(s1.data() == s2.data());
63 assert(s1.size() == s2.size());
64 assert(std::equal(s1.begin(), s1.end(), sp.end() - Count));
65 }
66
67
68 constexpr int carr1[] = {1,2,3,4};
69 int arr[] = {5,6,7};
70 std::string sarr [] = { "ABC", "DEF", "GHI", "JKL", "MNO"};
71
main()72 int main ()
73 {
74 {
75 using Sp = std::span<const int>;
76 static_assert(testConstexprSpan<Sp, 0>(Sp{}), "");
77
78 static_assert(testConstexprSpan<Sp, 0>(Sp{carr1}), "");
79 static_assert(testConstexprSpan<Sp, 1>(Sp{carr1}), "");
80 static_assert(testConstexprSpan<Sp, 2>(Sp{carr1}), "");
81 static_assert(testConstexprSpan<Sp, 3>(Sp{carr1}), "");
82 static_assert(testConstexprSpan<Sp, 4>(Sp{carr1}), "");
83 }
84
85 {
86 using Sp = std::span<const int, 4>;
87
88 static_assert(testConstexprSpan<Sp, 0>(Sp{carr1}), "");
89 static_assert(testConstexprSpan<Sp, 1>(Sp{carr1}), "");
90 static_assert(testConstexprSpan<Sp, 2>(Sp{carr1}), "");
91 static_assert(testConstexprSpan<Sp, 3>(Sp{carr1}), "");
92 static_assert(testConstexprSpan<Sp, 4>(Sp{carr1}), "");
93 }
94
95 {
96 using Sp = std::span<int>;
97 testRuntimeSpan<Sp, 0>(Sp{});
98
99 testRuntimeSpan<Sp, 0>(Sp{arr});
100 testRuntimeSpan<Sp, 1>(Sp{arr});
101 testRuntimeSpan<Sp, 2>(Sp{arr});
102 testRuntimeSpan<Sp, 3>(Sp{arr});
103 }
104
105 {
106 using Sp = std::span<int, 3>;
107
108 testRuntimeSpan<Sp, 0>(Sp{arr});
109 testRuntimeSpan<Sp, 1>(Sp{arr});
110 testRuntimeSpan<Sp, 2>(Sp{arr});
111 testRuntimeSpan<Sp, 3>(Sp{arr});
112 }
113
114 {
115 using Sp = std::span<std::string>;
116 testConstexprSpan<Sp, 0>(Sp{});
117
118 testRuntimeSpan<Sp, 0>(Sp{sarr});
119 testRuntimeSpan<Sp, 1>(Sp{sarr});
120 testRuntimeSpan<Sp, 2>(Sp{sarr});
121 testRuntimeSpan<Sp, 3>(Sp{sarr});
122 testRuntimeSpan<Sp, 4>(Sp{sarr});
123 testRuntimeSpan<Sp, 5>(Sp{sarr});
124 }
125
126 {
127 using Sp = std::span<std::string, 5>;
128
129 testRuntimeSpan<Sp, 0>(Sp{sarr});
130 testRuntimeSpan<Sp, 1>(Sp{sarr});
131 testRuntimeSpan<Sp, 2>(Sp{sarr});
132 testRuntimeSpan<Sp, 3>(Sp{sarr});
133 testRuntimeSpan<Sp, 4>(Sp{sarr});
134 testRuntimeSpan<Sp, 5>(Sp{sarr});
135 }
136 }
137