All you said you wanted to wanted to use D "in order to verify that rounding would be performed as expected."

I took that to mean you wanted to test packing/unpacking D in one perl and unpacking in the other. I'm guessing you want to test how D works with different Perl build settings. Is it not this?

Anyway, no need to be such a jerk just cause I didn't understand a vague statement you just made. If I got it wrong, just clarify what you meant.

In any case, unless you want to test sending NUL bytes as in arguments (which you can't do), you missed the point: It doesn't matter how to send the bytes over from one program to another, and all I did was suggest a way of doing this. It doesn't interfere with your attempts to test D in the least, contrary to your claims.