id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
9603	boost::optional operator<< does the wrong thing	a.luenser+boost@…	Fernando Cacciola	"{{{
template<class CharType, class CharTrait, class T>
inline std::basic_ostream<CharType, CharTrait>&
operator<<(std::basic_ostream<CharType, CharTrait>& out, optional<T> const& v)
{
  if ( out.good() )
  {
    if ( !v )
         out << ""--"" ;
    else out << ' ' << *v ;
  }

  return out;
}
}}}
This is the wrong semantics, in my opinion. Example of the problem:
{{{
std::string s(""--"");
boost::optional<std::string> o;
std::cout << s << std::endl;
std::cout << o << std::endl;
}}}
prints the same, which is clearly not intended. If the optional is not engaged (no value), printing should to nothing, i.e. return the stream unmodified. Also, the ' ' character in the code above should be removed."	Bugs	closed	To Be Determined	optional	Boost 1.55.0	Problem	invalid