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 const_iterator begin() const;
14
15#include <string_view>
16#include <cassert>
17
18#include "test_macros.h"
19
20template <class S>
21void test(S s) {
22 const S& cs = s;
23 typename S::iterator b = s.begin();
24 typename S::const_iterator cb1 = cs.begin();
25 typename S::const_iterator cb2 = s.cbegin();
26 if (!s.empty()) {
27 assert(*b == s[0]);
28 assert(&*b == &s[0]);
29 assert(*cb1 == s[0]);
30 assert(&*cb1 == &s[0]);
31 assert(*cb2 == s[0]);
32 assert(&*cb2 == &s[0]);
33 }
34 assert(b == cb1);
35 assert(b == cb2);
36 assert(cb1 == cb2);
37}
38
39int main(int, char**) {
40 typedef std::string_view string_view;
41#ifndef TEST_HAS_NO_CHAR8_T
42 typedef std::u8string_view u8string_view;
43#endif
44 typedef std::u16string_view u16string_view;
45 typedef std::u32string_view u32string_view;
46
47 test(string_view());
48 test(u16string_view());
49 test(u32string_view());
50 test(string_view("123"));
51#ifndef TEST_HAS_NO_CHAR8_T
52 test(u8string_view{u8"123"});
53#endif
54#if TEST_STD_VER >= 11
55 test(u16string_view{u"123"});
56 test(u32string_view{U"123"});
57#endif
58
59#ifndef TEST_HAS_NO_WIDE_CHARACTERS
60 typedef std::wstring_view wstring_view;
61 test(wstring_view());
62 test(wstring_view(L"123"));
63#endif
64
65#if TEST_STD_VER > 11
66 {
67 constexpr string_view sv{"123", 3};
68# ifndef TEST_HAS_NO_CHAR8_T
69 constexpr u8string_view u8sv{u8"123", 3};
70# endif
71 constexpr u16string_view u16sv{u"123", 3};
72 constexpr u32string_view u32sv{U"123", 3};
73
74 static_assert(*sv.begin() == sv[0], "");
75# ifndef TEST_HAS_NO_CHAR8_T
76 static_assert(*u8sv.begin() == u8sv[0], "");
77# endif
78 static_assert(*u16sv.begin() == u16sv[0], "");
79 static_assert(*u32sv.begin() == u32sv[0], "");
80
81 static_assert(*sv.cbegin() == sv[0], "");
82# ifndef TEST_HAS_NO_CHAR8_T
83 static_assert(*u8sv.cbegin() == u8sv[0], "");
84# endif
85 static_assert(*u16sv.cbegin() == u16sv[0], "");
86 static_assert(*u32sv.cbegin() == u32sv[0], "");
87
88# ifndef TEST_HAS_NO_WIDE_CHARACTERS
89 {
90 constexpr wstring_view wsv{L"123", 3};
91 static_assert(*wsv.begin() == wsv[0], "");
92 static_assert(*wsv.cbegin() == wsv[0], "");
93 }
94# endif
95 }
96#endif // TEST_STD_VER > 11
97
98 return 0;
99}
100

source code of libcxx/test/std/strings/string.view/string.view.iterators/begin.pass.cpp