[Boost-users] [format] print float number with fixed number of decimals *and* integer digits

I always found the rules for printf formatting, which Boost.Format uses, cryptic. I usually find the right combination by trial and error. In this case I want to print decimal numbers with both fixed number of integer digits and decimal digits. How can I do this with Boost.Format. #include #include<iostream> int main(){ int i = 2; std::cout << boost::format("%04i") % i << std::endl; //prints 0002, ok! double d = 3.1415; std::cout<< boost::format("%04.8f") % d << std::endl; // ^ prints 3.14150000, // want 0003.14150000 //(or even ' 3.14150000') //(or even ' 3.1415 ') return 0; } Thank you, Alfredo