**Guile Reference Manual**

#### 18.2.4.1 Integers

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
`SCM`

.

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.

__Macro:__ int **SCM_INUMP** *(SCM *`x`)
- Return non-zero iff
`x` is a small integer value.

__Macro:__ int **SCM_NINUMP** *(SCM *`x`)
- The complement of SCM_INUMP.

__Macro:__ int **SCM_INUM** *(SCM *`x`)
- Return the value of
`x` as an ordinary, C integer. If `x`
is not an INUM, the result is undefined.

__Macro:__ SCM **SCM_MAKINUM** *(int *`i`)
- Given a C integer
`i`, return its representation as an `SCM`

.
This function does not check for overflow.