As mentioned by evilrat earlier the 'string signature' should
probably be made a readonly property, set in the constructor. I
don't think D supports defining a constructor signature on
interfaces (I could be wrong), so you want to define an
invariant as part of the contract.
You may also want to protect the constructor and implement a
factory method (or equivalent) pattern.
I will need to look it up, but if I recall it may be possible
to define a 'final' function on the interface that can set the
'signature'.
I regret that I cannot at this time give you a definitive
answer as I'm not in my office where I could verify.
Thanks for the help:) I'm a newbie in D scene, so there should be
much more to learn.
