Ordinal number corresponding to the index in this choice's open type parameters of the type of the value stored in this choice.
Note that this is defined even for choices of ambiguous types like `option nil`: Even though this type may only contain `nil` it can still be distinguished:
is `0` while
is `1`.
Postcondition
post
debug: 0 <= result < CHOICE_ELEMENT_TYPE.count
parameters of the type of the value stored in this choice.
Note that this is defined even for choices of ambiguous types like
`option nil`: Even though this type may only contain `nil` it can
still be distinguished:
is `0` while
is `1`.