The following code example is taken from the book
The C++ Standard Library - A Tutorial and Reference
by Nicolai M. Josuttis, Addison-Wesley, 1999
© Copyright Nicolai M. Josuttis 1999
#include <iostream>
#include <sstream>
template <class charT, class traits>
inline
std::basic_ostream<charT,traits>&
operator << (std::basic_ostream<charT,traits>& strm,
const Fraction& f)
{
/* string stream
* - with same format
* - without special field width
*/
std::basic_ostringstream<charT,traits> s;
s.copyfmt(strm);
s.width(0);
// fill string stream
s << f.numerator() << '/' << f.denominator();
// print string stream
strm << s.str();
return strm;
}