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 // <string>
11 
12 //   bool starts_with(const CharT *x) const;
13 
14 #include <string>
15 #include <cassert>
16 
17 #include "test_macros.h"
18 
19 int main(int, char**)
20 {
21     {
22     typedef std::string S;
23     const char *s = "abcde";
24     S  s0 {};
25     S  s1 { s, 1 };
26     S  s2 { s, 2 };
27 //     S  s3 { s, 3 };
28 //     S  s4 { s, 4 };
29 //     S  s5 { s, 5 };
30     S  sNot {"def", 3 };
31 
32     LIBCPP_ASSERT_NOEXCEPT(s0.starts_with(""));
33 
34     assert ( s0.starts_with(""));
35     assert (!s0.starts_with("a"));
36 
37     assert ( s1.starts_with(""));
38     assert ( s1.starts_with("a"));
39     assert (!s1.starts_with("ab"));
40     assert (!s1.starts_with("abc"));
41     assert (!s1.starts_with("abcd"));
42     assert (!s1.starts_with("abcde"));
43     assert (!s1.starts_with("def"));
44 
45     assert ( s2.starts_with(""));
46     assert ( s2.starts_with("a"));
47     assert ( s2.starts_with("ab"));
48     assert (!s2.starts_with("abc"));
49     assert (!s2.starts_with("abcd"));
50     assert (!s2.starts_with("abcde"));
51     assert (!s2.starts_with("def"));
52 
53     assert ( sNot.starts_with(""));
54     assert (!sNot.starts_with("a"));
55     assert (!sNot.starts_with("ab"));
56     assert (!sNot.starts_with("abc"));
57     assert (!sNot.starts_with("abcd"));
58     assert (!sNot.starts_with("abcde"));
59     assert ( sNot.starts_with("def"));
60     }
61 
62   return 0;
63 }
64