5 Function and Macro Reference

null-pointer-p

Function

Summary

Tests a pointer to see if it is a null pointer.

Package

fli

Signature

null-pointer-p pointer => boolean

Arguments

pointer: An FLI pointer.

Values

boolean: If pointer is a null pointer (that is, a pointer pointing to address 0) thent is returned, otherwisenull-pointer-p returnsnil.

Description

The functionnull-pointer-p is used to determine if a pointer is a null pointer. A null pointer is a pointer pointing to address 0.

Example

In the following example a pointer to an:int is defined, and tested withnull-pointer-p. The pointer is then freed, becoming a null pointer, and is once again tested usingnull-pointer-p.

(setq point (fli:allocate-foreign-object :type :int))

(fli:null-pointer-p point)

(fli:free-foreign-object point)

(fli:null-pointer-p point)

See Also
: pointer-address
: pointer-eq