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 <cassert>
16#include <cstddef>
17#include <string_view>
18
19#include "test_macros.h"
20
21template <typename CharT>
22void test(const CharT* s, std::size_t len) {
23 typedef std::basic_string_view<CharT> SV;
24 {
25 SV sv1(s);
26 assert(sv1.size() == len);
27 assert(sv1.data() == s);
28
29 if (len > 0) {
30 sv1.remove_prefix(1);
31 assert(sv1.size() == (len - 1));
32 assert(sv1.data() == (s + 1));
33 sv1.remove_prefix(len - 1);
34 }
35
36 assert(sv1.size() == 0);
37 sv1.remove_prefix(0);
38 assert(sv1.size() == 0);
39 }
40}
41
42#if TEST_STD_VER > 11
43constexpr std::size_t test_ce(size_t n, size_t k) {
44 typedef std::basic_string_view<char> SV;
45 SV sv1{"ABCDEFGHIJKL", n};
46 sv1.remove_prefix(k);
47 return sv1.size();
48}
49#endif
50
51int main(int, char**) {
52 test(s: "ABCDE", len: 5);
53 test(s: "a", len: 1);
54 test(s: "", len: 0);
55
56#ifndef TEST_HAS_NO_WIDE_CHARACTERS
57 test(s: L"ABCDE", len: 5);
58 test(s: L"a", len: 1);
59 test(s: L"", len: 0);
60#endif
61
62#if TEST_STD_VER >= 11
63 test(u"ABCDE", 5);
64 test(u"a", 1);
65 test(u"", 0);
66
67 test(U"ABCDE", 5);
68 test(U"a", 1);
69 test(U"", 0);
70#endif
71
72#if TEST_STD_VER > 11
73 {
74 static_assert(test_ce(5, 0) == 5, "");
75 static_assert(test_ce(5, 1) == 4, "");
76 static_assert(test_ce(5, 5) == 0, "");
77 static_assert(test_ce(9, 3) == 6, "");
78 }
79#endif
80
81 return 0;
82}
83

source code of libcxx/test/std/strings/string.view/string.view.modifiers/remove_prefix.pass.cpp