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 svNot {"def", 3 };
30
31 LIBCPP_ASSERT_NOEXCEPT(sv0.starts_with(""));
32
33 assert ( sv0.starts_with(""));
34 assert (!sv0.starts_with("a"));
35
36 assert ( sv1.starts_with(""));
37 assert ( sv1.starts_with("a"));
38 assert (!sv1.starts_with("ab"));
39 assert (!sv1.starts_with("abc"));
40 assert (!sv1.starts_with("abcd"));
41 assert (!sv1.starts_with("abcde"));
42 assert (!sv1.starts_with("def"));
43
44 assert ( sv2.starts_with(s + 5));
45 assert ( sv2.starts_with("a"));
46 assert ( sv2.starts_with("ab"));
47 assert (!sv2.starts_with("abc"));
48 assert (!sv2.starts_with("abcd"));
49 assert (!sv2.starts_with("abcde"));
50 assert (!sv2.starts_with("def"));
51
52 assert ( svNot.starts_with(""));
53 assert (!svNot.starts_with("a"));
54 assert (!svNot.starts_with("ab"));
55 assert (!svNot.starts_with("abc"));
56 assert (!svNot.starts_with("abcd"));
57 assert (!svNot.starts_with("abcde"));
58 assert ( svNot.starts_with("def"));
59 }
60
61 #if TEST_STD_VER > 11
62 {
63 typedef std::basic_string_view<char, constexpr_char_traits<char>> SV;
64 constexpr const char *s = "abcde";
65 constexpr SV sv0 {};
66 constexpr SV sv1 { s, 1 };
67 constexpr SV sv2 { s, 2 };
68 constexpr SV svNot {"def", 3 };
69
70 static_assert ( sv0.starts_with(""), "" );
71 static_assert (!sv0.starts_with("a"), "" );
72
73 static_assert ( sv1.starts_with(""), "" );
74 static_assert ( sv1.starts_with("a"), "" );
75 static_assert (!sv1.starts_with("ab"), "" );
76 static_assert (!sv1.starts_with("abc"), "" );
77 static_assert (!sv1.starts_with("abcd"), "" );
78 static_assert (!sv1.starts_with("abcde"), "" );
79 static_assert (!sv1.starts_with("def"), "" );
80
81 static_assert ( sv2.starts_with(s + 5), "" );
82 static_assert ( sv2.starts_with("a"), "" );
83 static_assert ( sv2.starts_with("ab"), "" );
84 static_assert (!sv2.starts_with("abc"), "" );
85 static_assert (!sv2.starts_with("abcd"), "" );
86 static_assert (!sv2.starts_with("abcde"), "" );
87 static_assert (!sv2.starts_with("def"), "" );
88
89 static_assert ( svNot.starts_with(""), "" );
90 static_assert (!svNot.starts_with("a"), "" );
91 static_assert (!svNot.starts_with("ab"), "" );
92 static_assert (!svNot.starts_with("abc"), "" );
93 static_assert (!svNot.starts_with("abcd"), "" );
94 static_assert (!svNot.starts_with("abcde"), "" );
95 static_assert ( svNot.starts_with("def"), "" );
96 }
97 #endif
98
99 return 0;
100 }
101