ostream& operator <<( char ch );
ostream& operator <<( unsigned char uch );
ostream& operator <<( signed char sch );
ostream& operator <<( const char* psz );
ostream& operator <<( const unsigned char *pusz );
ostream& operator <<( const signed char *pssz );
ostream& operator <<( short s );
ostream& operator <<( unsigned short us );
ostream& operator <<( int n );
ostream& operator <<( unsigned int un );
ostream& operator <<( long l );
ostream& operator <<( unsigned long ul );
ostream& operator <<( float f );
ostream& operator <<( double d );
ostream& operator <<( long double ld );
ostream& operator <<( void* pv );
ostream& operator <<( streambuf* psb );
ostream& operator <<( ostream& (*fcn)(ostream&) );
ostream& operator <<( ios& (*fcn)(ios&) );
These overloaded operators insert their argument into the stream. The last two variations allow the use of manipulators that are defined for both ostream and ios.