1 //===----------------------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 // <string>
11 
12 // basic_string()
13 //        noexcept(is_nothrow_default_constructible<allocator_type>::value);
14 
15 // This tests a conforming extension
16 
17 #include <string>
18 #include <cassert>
19 
20 #include "../test_allocator.h"
21 
22 template <class T>
23 struct some_alloc
24 {
25     typedef T value_type;
26     some_alloc(const some_alloc&);
27 };
28 
29 int main()
30 {
31 #if __has_feature(cxx_noexcept)
32     {
33         typedef std::string C;
34         static_assert(std::is_nothrow_default_constructible<C>::value, "");
35     }
36     {
37         typedef std::basic_string<char, std::char_traits<char>, test_allocator<char>> C;
38         static_assert(std::is_nothrow_default_constructible<C>::value, "");
39     }
40     {
41         typedef std::basic_string<char, std::char_traits<char>, some_alloc<char>> C;
42         static_assert(!std::is_nothrow_default_constructible<C>::value, "");
43     }
44 #endif
45 }
46