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 // UNSUPPORTED: c++98, c++03
11 
12 // <ostream>
13 
14 // template <class charT, class traits = char_traits<charT> >
15 //   class basic_ostream;
16 
17 // template <class charT, class traits, class T>
18 //   basic_ostream<charT, traits>&
19 //   operator<<(basic_ostream<charT, traits>&& os, const T& x);
20 
21 #include <ostream>
22 #include <cassert>
23 
24 
25 template <class CharT>
26 class testbuf
27     : public std::basic_streambuf<CharT>
28 {
29     typedef std::basic_streambuf<CharT> base;
30     std::basic_string<CharT> str_;
31 public:
testbuf()32     testbuf()
33     {
34     }
35 
str() const36     std::basic_string<CharT> str() const
37         {return std::basic_string<CharT>(base::pbase(), base::pptr());}
38 
39 protected:
40 
41     virtual typename base::int_type
overflow(typename base::int_type ch=base::traits_type::eof ())42         overflow(typename base::int_type ch = base::traits_type::eof())
43         {
44             if (ch != base::traits_type::eof())
45             {
46                 int n = static_cast<int>(str_.size());
47                 str_.push_back(static_cast<CharT>(ch));
48                 str_.resize(str_.capacity());
49                 base::setp(const_cast<CharT*>(str_.data()),
50                            const_cast<CharT*>(str_.data() + str_.size()));
51                 base::pbump(n+1);
52             }
53             return ch;
54         }
55 };
56 
57 
main()58 int main()
59 {
60     {
61         testbuf<char> sb;
62         std::ostream(&sb) << "testing...";
63         assert(sb.str() == "testing...");
64     }
65     {
66         testbuf<wchar_t> sb;
67         std::wostream(&sb) << L"123";
68         assert(sb.str() == L"123");
69     }
70 }
71