Tests a pointer to see if it is a null pointer.
null-pointer-p pointer => result
A FLI pointer.
null-pointer-p is used to determine if a pointer is a null pointer. A null pointer is a pointer pointing to address 0.
If pointer is a null pointer (that is, a pointer pointing to address 0) then result is true, otherwise
null-pointer-p returns false.
In the following example a pointer to an
:int is defined, and tested with
null-pointer-p. The pointer is then freed, becoming a null pointer, and is once again tested using
(setq point (fli:allocate-foreign-object :type :int))
LispWorks Foreign Language Interface User Guide and Reference Manual - 29 Sep 2017