proposal: capacity variable for dynamic arrays

[Lionello Lunesu]

What's the capacity of a slice?

Futhermore, the capacity can't be stored in the memory block, since you 
don't know the start and end of the block. Could be stored in the array 
variables itself (as are length and ptr), but that would make the 
sizeof(array) and strange 12, probably being padded to 16, resulting in 
twice the mem transfer for array arguments, return values.

L.