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 // <ostream>
11 
12 // template <class charT, class traits = char_traits<charT> >
13 //   class basic_ostream;
14 
15 // basic_ostream<charT,traits>& operator<<(basic_ios<charT,traits>&
16 //                                         (*pf)(basic_ios<charT,traits>&));
17 
18 #include <ostream>
19 #include <cassert>
20 
21 template <class CharT>
22 class testbuf
23     : public std::basic_streambuf<CharT>
24 {
25     typedef std::basic_streambuf<CharT> base;
26     std::basic_string<CharT> str_;
27 public:
28     testbuf()
29     {
30     }
31 
32     std::basic_string<CharT> str() const
33         {return std::basic_string<CharT>(base::pbase(), base::pptr());}
34 
35 protected:
36 
37     virtual typename base::int_type
38         overflow(typename base::int_type __c = base::traits_type::eof())
39         {
40             if (__c != base::traits_type::eof())
41             {
42                 int n = str_.size();
43                 str_.push_back(__c);
44                 str_.resize(str_.capacity());
45                 base::setp(const_cast<CharT*>(str_.data()),
46                            const_cast<CharT*>(str_.data() + str_.size()));
47                 base::pbump(n+1);
48             }
49             return __c;
50         }
51 };
52 
53 template <class CharT>
54 std::basic_ios<CharT>&
55 f(std::basic_ios<CharT>& os)
56 {
57     std::uppercase(os);
58     return os;
59 }
60 
61 int main()
62 {
63     {
64         testbuf<char> sb;
65         std::ostream os(&sb);
66         assert(!(os.flags() & std::ios_base::uppercase));
67         os << f;
68         assert( (os.flags() & std::ios_base::uppercase));
69     }
70 }
71