Re: Help converting this Write to operator<< overload

I have a CSkill class which is rather complex as it is recursive. That
is:

class CSkill
{
public:
   CSkill( std::string Name, float Value ): Name_( Name ), Value_(
Value )
{};
   void Update( const std::string& Name, const float Value );
   float Value( const std::string& Name ) const;
   float Sum( const std::string& Name ) const;
   void Write( std::ostream& os, const std::string& Prefix ) const;

   std::string CSkill::PlainName( const std::string& Name ) const;

   friend std::istream& operator>>( std::istream& is, CSkill& Skill);

private:
   float Sum() const;

   std::string Name_;
   float Value_;
   std::map< std::string, CSkill > Skills_;

};

Well, to output this class to an ostream, I use this function:

void CSkill::Write( std::ostream& os, const std::string& Prefix ) const
{
   if ( Name_.length() > 0 && Value_ > 0 )
       os << Prefix << Name_ << " " << Value_ << std::endl;
   for ( std::map< std::string, CSkill >::const_iterator it =
Skills_.begin(); it != Skills_.end(); ++it )
   {
       (*it).second.Write( os, ( Name_.length() > 0 ? Prefix + Name_ +
"|"
: "" ) );
   }
}

but I would prefer to use
std::ostream& operator<<( /* what goes here? */ )

The problem I see is that I need to pass that extra parameter, a
std::string, which is used in the recursion. Is something like this
allowed?
outfile << Skills( "" ) << SomethingElse