Here are functions for operating on small integers, that fit within an
SCM. Such integers are called immediate numbers, or
INUMs. In general, INUMs occupy all but two bits of an
Bignums and floating-point numbers are non-immediate objects, and have their own, separate accessors. The functions here will not work on them. This is not as much of a problem as you might think, however, because the system never constructs bignums that could fit in an INUM, and never uses floating point values for exact integers.
Return the value of x as an ordinary, C integer. If x is not an INUM, the result is undefined.