test/std/input.output/iostream.format/output.streams/ostream.formatted/ostream.inserters/streambuf.pass.cpp

   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_streambuf<charT,traits>* sb);
  16
  17 #include <ostream>
  18 #include <cassert>
  19
  20 template <class CharT>
  21 class testbuf
  22     : public std::basic_streambuf<CharT>
  23 {
  24     typedef std::basic_streambuf<CharT> base;
  25     std::basic_string<CharT> str_;
  26 public:
  27     testbuf()
  28     {
  29     }
  30     testbuf(const std::basic_string<CharT>& str)
  31         : str_(str)
  32     {
  33         base::setg(const_cast<CharT*>(str_.data()),
  34                    const_cast<CharT*>(str_.data()),
  35                    const_cast<CharT*>(str_.data() + str_.size()));
  36     }
  37
  38     std::basic_string<CharT> str() const
  39         {return std::basic_string<CharT>(base::pbase(), base::pptr());}
  40
  41 protected:
  42
  43     virtual typename base::int_type
  44         overflow(typename base::int_type __c = base::traits_type::eof())
  45         {
  46             if (__c != base::traits_type::eof())
  47             {
  48                 int n = static_cast<int>(str_.size());
  49                 str_.push_back(static_cast<CharT>(__c));
  50                 str_.resize(str_.capacity());
  51                 base::setp(const_cast<CharT*>(str_.data()),
  52                            const_cast<CharT*>(str_.data() + str_.size()));
  53                 base::pbump(n+1);
  54             }
  55             return __c;
  56         }
  57 };
  58
  59 int main()
  60 {
  61     {
  62         testbuf<char> sb;
  63         std::ostream os(&sb);
  64         testbuf<char> sb2("testing...");
  65         assert(sb.str() == "");
  66         os << &sb2;
  67         assert(sb.str() == "testing...");
  68     }
  69 }