Add leading zero's to string, without (s)printf

Question

I want to add a variable of leading zero\'s to a string. I couldn\'t find anything on Google, without someone mentioning (s)printf, but I want to do this without (s)printf.<

Answer 1

This works well for me. You don't need to switch setfill back to ' ', as this a temporary stream.

std::string to_zero_lead(const int value, const unsigned precision)
{
     std::ostringstream oss;
     oss << std::setw(precision) << std::setfill('0') << value;
     return oss.str();
}