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
9 // UNSUPPORTED: c++03, c++11, c++14, c++17
10
11 // <string_view>
12
13 // constexpr bool starts_with(string_view x) const noexcept;
14
15 #include <string_view>
16 #include <cassert>
17
18 #include "test_macros.h"
19 #include "constexpr_char_traits.h"
20
main(int,char **)21 int main(int, char**)
22 {
23 {
24 typedef std::string_view SV;
25 const char *s = "abcde";
26 SV sv0 {};
27 SV sv1 { s, 1 };
28 SV sv2 { s, 2 };
29 // SV sv3 { s, 3 };
30 // SV sv4 { s, 4 };
31 // SV sv5 { s, 5 };
32 SV svNot {"def", 3 };
33
34 LIBCPP_ASSERT_NOEXCEPT(sv0.starts_with(""));
35
36 assert ( sv0.starts_with(""));
37 assert (!sv0.starts_with("a"));
38
39 assert ( sv1.starts_with(""));
40 assert ( sv1.starts_with("a"));
41 assert (!sv1.starts_with("ab"));
42 assert (!sv1.starts_with("abc"));
43 assert (!sv1.starts_with("abcd"));
44 assert (!sv1.starts_with("abcde"));
45 assert (!sv1.starts_with("def"));
46
47 assert ( sv2.starts_with(s + 5));
48 assert ( sv2.starts_with("a"));
49 assert ( sv2.starts_with("ab"));
50 assert (!sv2.starts_with("abc"));
51 assert (!sv2.starts_with("abcd"));
52 assert (!sv2.starts_with("abcde"));
53 assert (!sv2.starts_with("def"));
54
55 assert ( svNot.starts_with(""));
56 assert (!svNot.starts_with("a"));
57 assert (!svNot.starts_with("ab"));
58 assert (!svNot.starts_with("abc"));
59 assert (!svNot.starts_with("abcd"));
60 assert (!svNot.starts_with("abcde"));
61 assert ( svNot.starts_with("def"));
62 }
63
64 #if TEST_STD_VER > 11
65 {
66 typedef std::basic_string_view<char, constexpr_char_traits<char>> SV;
67 constexpr const char *s = "abcde";
68 constexpr SV sv0 {};
69 constexpr SV sv1 { s, 1 };
70 constexpr SV sv2 { s, 2 };
71 // constexpr SV sv3 { s, 3 };
72 // constexpr SV sv4 { s, 4 };
73 // constexpr SV sv5 { s, 5 };
74 constexpr SV svNot {"def", 3 };
75
76 static_assert ( sv0.starts_with(""), "" );
77 static_assert (!sv0.starts_with("a"), "" );
78
79 static_assert ( sv1.starts_with(""), "" );
80 static_assert ( sv1.starts_with("a"), "" );
81 static_assert (!sv1.starts_with("ab"), "" );
82 static_assert (!sv1.starts_with("abc"), "" );
83 static_assert (!sv1.starts_with("abcd"), "" );
84 static_assert (!sv1.starts_with("abcde"), "" );
85 static_assert (!sv1.starts_with("def"), "" );
86
87 static_assert ( sv2.starts_with(s + 5), "" );
88 static_assert ( sv2.starts_with("a"), "" );
89 static_assert ( sv2.starts_with("ab"), "" );
90 static_assert (!sv2.starts_with("abc"), "" );
91 static_assert (!sv2.starts_with("abcd"), "" );
92 static_assert (!sv2.starts_with("abcde"), "" );
93 static_assert (!sv2.starts_with("def"), "" );
94
95 static_assert ( svNot.starts_with(""), "" );
96 static_assert (!svNot.starts_with("a"), "" );
97 static_assert (!svNot.starts_with("ab"), "" );
98 static_assert (!svNot.starts_with("abc"), "" );
99 static_assert (!svNot.starts_with("abcd"), "" );
100 static_assert (!svNot.starts_with("abcde"), "" );
101 static_assert ( svNot.starts_with("def"), "" );
102 }
103 #endif
104
105 return 0;
106 }
107