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 _CharT& front();
14
15#include <string_view>
16#include <cassert>
17
18#include "test_macros.h"
19
20template <typename CharT>
21bool test(const CharT* s, std::size_t len) {
22 typedef std::basic_string_view<CharT> SV;
23 SV sv(s, len);
24 ASSERT_SAME_TYPE(decltype(sv.back()), typename SV::const_reference);
25 LIBCPP_ASSERT_NOEXCEPT(sv.back());
26 assert(sv.length() == len);
27 assert(sv.back() == s[len - 1]);
28 return &sv.back() == s + len - 1;
29}
30
31int main(int, char**) {
32 assert(test("ABCDE", 5));
33 assert(test("a", 1));
34
35#ifndef TEST_HAS_NO_WIDE_CHARACTERS
36 assert(test(L"ABCDE", 5));
37 assert(test(L"a", 1));
38#endif
39
40#if TEST_STD_VER >= 11
41 assert(test(u"ABCDE", 5));
42 assert(test(u"a", 1));
43
44 assert(test(U"ABCDE", 5));
45 assert(test(U"a", 1));
46#endif
47
48#if TEST_STD_VER >= 11
49 {
50 constexpr std::basic_string_view<char> sv("ABC", 2);
51 static_assert(sv.length() == 2, "");
52 static_assert(sv.back() == 'B', "");
53 }
54#endif
55
56 return 0;
57}
58

source code of libcxx/test/std/strings/string.view/string.view.access/back.pass.cpp