xref: /llvm-project/libcxx/test/std/strings/string.view/string.view.access/index.pass.cpp (revision a40bada91aeda276a772acfbcae6e8de26755a11)
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& operator[](size_type _pos) const;
14 
15 #include <string_view>
16 #include <cassert>
17 
18 #include "test_macros.h"
19 
20 template <typename CharT>
test(const CharT * s,std::size_t len)21 void 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[0]), typename SV::const_reference);
25   LIBCPP_ASSERT_NOEXCEPT(sv[0]);
26   assert(sv.length() == len);
27   for (std::size_t i = 0; i < len; ++i) {
28     assert(sv[i] == s[i]);
29     assert(&sv[i] == s + i);
30   }
31 }
32 
main(int,char **)33 int main(int, char**) {
34   test("ABCDE", 5);
35   test("a", 1);
36 
37 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
38   test(L"ABCDE", 5);
39   test(L"a", 1);
40 #endif
41 
42 #if TEST_STD_VER >= 11
43   test(u"ABCDE", 5);
44   test(u"a", 1);
45 
46   test(U"ABCDE", 5);
47   test(U"a", 1);
48 #endif
49 
50 #if TEST_STD_VER > 11
51   {
52     constexpr std::basic_string_view<char> sv("ABC", 2);
53     static_assert(sv.length() == 2, "");
54     static_assert(sv[0] == 'A', "");
55     static_assert(sv[1] == 'B', "");
56   }
57 #endif
58 
59   return 0;
60 }
61