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: !stdlib=libc++ && (c++03 || c++11 || c++14)
10
11 // <string_view>
12
13 // void remove_prefix(size_type _n)
14
15 #include <string_view>
16 #include <cassert>
17
18 #include "test_macros.h"
19
20 template<typename CharT>
test(const CharT * s,size_t len)21 void test ( const CharT *s, size_t len ) {
22 typedef std::basic_string_view<CharT> SV;
23 {
24 SV sv1 ( s );
25 assert ( sv1.size() == len );
26 assert ( sv1.data() == s );
27
28 if ( len > 0 ) {
29 sv1.remove_prefix ( 1 );
30 assert ( sv1.size() == (len - 1));
31 assert ( sv1.data() == (s + 1));
32 sv1.remove_prefix ( len - 1 );
33 }
34
35 assert ( sv1.size() == 0 );
36 sv1.remove_prefix ( 0 );
37 assert ( sv1.size() == 0 );
38 }
39 }
40
41 #if TEST_STD_VER > 11
test_ce(size_t n,size_t k)42 constexpr size_t test_ce ( size_t n, size_t k ) {
43 typedef std::basic_string_view<char> SV;
44 SV sv1{ "ABCDEFGHIJKL", n };
45 sv1.remove_prefix ( k );
46 return sv1.size();
47 }
48 #endif
49
main(int,char **)50 int main(int, char**) {
51 test ( "ABCDE", 5 );
52 test ( "a", 1 );
53 test ( "", 0 );
54
55 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
56 test ( L"ABCDE", 5 );
57 test ( L"a", 1 );
58 test ( L"", 0 );
59 #endif
60
61 #if TEST_STD_VER >= 11
62 test ( u"ABCDE", 5 );
63 test ( u"a", 1 );
64 test ( u"", 0 );
65
66 test ( U"ABCDE", 5 );
67 test ( U"a", 1 );
68 test ( U"", 0 );
69 #endif
70
71 #if TEST_STD_VER > 11
72 {
73 static_assert ( test_ce ( 5, 0 ) == 5, "" );
74 static_assert ( test_ce ( 5, 1 ) == 4, "" );
75 static_assert ( test_ce ( 5, 5 ) == 0, "" );
76 static_assert ( test_ce ( 9, 3 ) == 6, "" );
77 }
78 #endif
79
80 return 0;
81 }
82