How to format doubles in the following way?

I am using C++ and I would like to format doubles in the following obvious way. I have tried playing with 'fixed' and 'scientific' using stringstream, but I am unable to achieve this desired output.

double d = -5; // print "-5"
double d = 1000000000; // print "1000000000"
double d = 3.14; // print "3.14"
double d = 0.00000000001; // print "0.00000000001"