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: c++98, c++03, c++11, c++14
10 // UNSUPPORTED: libcpp-no-deduction-guides
11 
12 // <string_view>
13 
14 // Test that the constructors offered by std::basic_string_view are formulated
15 // so they're compatible with implicit deduction guides.
16 
17 #include <string_view>
18 #include <cassert>
19 
20 #include "test_macros.h"
21 #include "constexpr_char_traits.h"
22 
23 // Overloads
24 // ---------------
25 // (1)  basic_string_view() - NOT TESTED
26 // (2)  basic_string_view(const basic_string_view&)
27 // (3)  basic_string_view(const CharT*, size_type)
28 // (4)  basic_string_view(const CharT*)
29 int main(int, char**)
30 {
31   { // Testing (1)
32     // Nothing to do. Cannot deduce without any arguments.
33   }
34   { // Testing (2)
35     const std::string_view sin("abc");
36     std::basic_string_view s(sin);
37     ASSERT_SAME_TYPE(decltype(s), std::string_view);
38     assert(s == "abc");
39 
40     using WSV = std::basic_string_view<wchar_t, constexpr_char_traits<wchar_t>>;
41     const WSV win(L"abcdef");
42     std::basic_string_view w(win);
43     ASSERT_SAME_TYPE(decltype(w), WSV);
44     assert(w == L"abcdef");
45   }
46   { // Testing (3)
47     std::basic_string_view s("abc", 2);
48     ASSERT_SAME_TYPE(decltype(s), std::string_view);
49     assert(s == "ab");
50 
51     std::basic_string_view w(L"abcdef", 4);
52     ASSERT_SAME_TYPE(decltype(w), std::wstring_view);
53     assert(w == L"abcd");
54   }
55   { // Testing (4)
56     std::basic_string_view s("abc");
57     ASSERT_SAME_TYPE(decltype(s), std::string_view);
58     assert(s == "abc");
59 
60     std::basic_string_view w(L"abcdef");
61     ASSERT_SAME_TYPE(decltype(w), std::wstring_view);
62     assert(w == L"abcdef");
63   }
64 
65   return 0;
66 }
67