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 // REQUIRES: locale.en_US.UTF-8
10 
11 // <ios>
12 
13 // class ios_base
14 
15 // void register_callback(event_callback fn, int index);
16 
17 #include <ios>
18 #include <string>
19 #include <locale>
20 #include <cassert>
21 
22 #include "test_macros.h"
23 #include "platform_support.h" // locale name macros
24 
25 class test
26     : public std::ios
27 {
28 public:
29     test()
30     {
31         init(0);
32     }
33 };
34 
35 int f1_called = 0;
36 
37 void f1(std::ios_base::event ev, std::ios_base& stream, int index)
38 {
39     if (ev == std::ios_base::imbue_event)
40     {
41         assert(stream.getloc().name() == LOCALE_en_US_UTF_8);
42         assert(index == 4);
43         ++f1_called;
44     }
45 }
46 
47 int main(int, char**)
48 {
49     test t;
50     std::ios_base& b = t;
51     b.register_callback(f1, 4);
52     b.register_callback(f1, 4);
53     b.register_callback(f1, 4);
54     std::locale l = b.imbue(std::locale(LOCALE_en_US_UTF_8));
55     assert(f1_called == 3);
56 
57   return 0;
58 }
59