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// constexpr basic_string_view substr(size_type pos = 0, size_type n = npos) const;
14
15// Throws: out_of_range if pos > size().
16// Effects: Determines the effective length rlen of the string to reference as the smaller of n and size() - pos.
17// Returns: basic_string_view(data()+pos, rlen).
18
19#include <algorithm>
20#include <cassert>
21#include <cstddef>
22#include <stdexcept>
23#include <string_view>
24
25#include "test_macros.h"
26
27template <typename CharT>
28void test1(std::basic_string_view<CharT> sv, std::size_t n, size_t pos) {
29 std::basic_string_view<CharT> sv1;
30#ifdef TEST_HAS_NO_EXCEPTIONS
31 if (pos > sv.size())
32 return; // would throw if exceptions were enabled
33 sv1 = sv.substr(pos, n);
34#else
35 try {
36 sv1 = sv.substr(pos, n);
37 assert(pos <= sv.size());
38 } catch (const std::out_of_range&) {
39 assert(pos > sv.size());
40 return;
41 }
42#endif
43 const std::size_t rlen = std::min(n, sv.size() - pos);
44 assert(sv1.size() == rlen);
45 for (std::size_t i = 0; i < rlen; ++i)
46 assert(sv[pos + i] == sv1[i]);
47}
48
49template <typename CharT>
50void test(const CharT* s) {
51 typedef std::basic_string_view<CharT> string_view_t;
52
53 string_view_t sv1(s);
54
55 test1(sv1, 0, 0);
56 test1(sv1, 1, 0);
57 test1(sv1, 20, 0);
58 test1(sv1, sv1.size(), 0);
59
60 test1(sv1, 0, 3);
61 test1(sv1, 2, 3);
62 test1(sv1, 100, 3);
63
64 test1(sv1, 0, string_view_t::npos);
65 test1(sv1, 2, string_view_t::npos);
66 test1(sv1, sv1.size(), string_view_t::npos);
67
68 test1(sv1, sv1.size() + 1, 0);
69 test1(sv1, sv1.size() + 1, 1);
70 test1(sv1, sv1.size() + 1, string_view_t::npos);
71}
72
73int main(int, char**) {
74 test(s: "ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE");
75 test(s: "ABCDE");
76 test(s: "a");
77 test(s: "");
78
79#ifndef TEST_HAS_NO_WIDE_CHARACTERS
80 test(s: L"ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE");
81 test(s: L"ABCDE");
82 test(s: L"a");
83 test(s: L"");
84#endif
85
86#if TEST_STD_VER >= 11
87 test(u"ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE");
88 test(u"ABCDE");
89 test(u"a");
90 test(u"");
91
92 test(U"ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE");
93 test(U"ABCDE");
94 test(U"a");
95 test(U"");
96#endif
97
98#if TEST_STD_VER > 11
99 {
100 constexpr std::string_view sv1{"ABCDE", 5};
101
102 {
103 constexpr std::string_view sv2 = sv1.substr(0, 3);
104 static_assert(sv2.size() == 3, "");
105 static_assert(sv2[0] == 'A', "");
106 static_assert(sv2[1] == 'B', "");
107 static_assert(sv2[2] == 'C', "");
108 }
109
110 {
111 constexpr std::string_view sv2 = sv1.substr(3, 0);
112 static_assert(sv2.size() == 0, "");
113 }
114
115 {
116 constexpr std::string_view sv2 = sv1.substr(3, 3);
117 static_assert(sv2.size() == 2, "");
118 static_assert(sv2[0] == 'D', "");
119 static_assert(sv2[1] == 'E', "");
120 }
121 }
122#endif
123
124 return 0;
125}
126

source code of libcxx/test/std/strings/string.view/string.view.ops/substr.pass.cpp