Don wrote:
The most important issues would be fixed with a small-value optimisation (values x where -long.max <= x <= long.max stored in the struct).
Drat, I thought it already did that.I think it's also important to make BigInt.sizeof == ulong.sizeof. To that end, you can use the least significant bit to mean "this is not a pointer", as in a 63 bit integer << 1.
(Pointers will always be aligned.)
