As far as I understand, padding bits are indeterminate until you observe them via a memcpy into a buffer, at which point they will collapse (only in the buffer) to some arbitrary but now-constant value. Is this correct?
edit: interestingly, Biriba is yet another game in the canasta family, my theory is that different groups were originally playing these differents variants, but when they gained knowledge of the more popular variant (burraco), they started playing it but kept calling it with the original name. I guess that up until the internet era, these games were mostly passed via oral knowledge in casual groups.
edit2: macchiavelli [1] is another very fun game of the same family, but a lot more puzzle solving oriented.
[1] https://en.wikipedia.org/wiki/Machiavelli_(Italian_card_game...
I appreciate your edits, by the way ;)
And it seem that I should double check which comment I'm editing before submitting :)