andy.roberts (10/4/2010)
I don't know why there's this difference between declare and cast/convert
Nobody does, I think. π
Probably for historical (hysterical?) reasons.
But this difference has already been the subject of many QotD's, and this is also exactly why HΓ₯kan suggests (and I fully agree with him) that one should never rely on the default, but always explicitly declare the length.