Example 1:
> printdouble(3);
0x4008000000000000
Example 2:
> prec=100!;
> verbosity = 1!;
> printdouble(exp(5));
Warning: the given expression is not a constant but an expression to evaluate. A faithful evaluation will be used.
Warning: rounding down occurred before printing a value as a double.
0x40628d389970338f