What it the preferred method to write a class to a file?

[xs0]

> P.S.:  Is there a standard library routine for converting
> between strings of length 4 and uint-s?  If so I wasn't able
> to find it.  If not, I wasn't able to determine that it
> didn't exist.  (That would have made writing the sig more
> efficient.)

union {
     uint asUInt;
     char[4] asChars;
}

or something to that effect :)