Equivalent of %02d with std::stringstream?

Question

I want to output an integer to a std::stringstream with the equivalent format of printf's %02d. Is there an easier way to achieve this than:

std::stringstream stream; stream.setfill('0'); stream.setw(2); stream << value; 

Is it possible to stream some sort of format flags to the stringstream, something like (pseudocode):

stream << flags("%02d") << value; 

Answer 1

You can use the standard manipulators from <iomanip> but there isn't a neat one that does both fill and width at once:

stream << std::setfill('0') << std::setw(2) << value; 

It wouldn't be hard to write your own object that when inserted into the stream performed both functions:

stream << myfillandw( '0', 2 ) << value; 

E.g.

struct myfillandw {     myfillandw( char f, int w )         : fill(f), width(w) {}      char fill;     int width; };  std::ostream& operator<<( std::ostream& o, const myfillandw& a ) {     o.fill( a.fill );     o.width( a.width );     return o; } 

Answer 2

You can use

stream<<setfill('0')<<setw(2)<<value;