




If pointer1 points to the same address as pointer2, pointer-eq returns t, otherwise it returns nil.
The function pointer-eq tests whether two pointers point to the same address, and returns t if they do, and nil if they do not.
In the following example a pointer, point1, is defined, and point2 is set equal to it. Both are then tested to see if they are equal to each other using pointer-eq. Then point2 is defined to point to a different object, and the two pointers are tested for equality again.
(setq point1 (fli:allocate-foreign-object :type :int))
(setq point2 point1)
(fli:pointer-eq point1 point2)
(setq point2 (fli:allocate-foreign-object :type :int))
(fli:pointer-eq point1 point2)
LispWorks Foreign Language Interface User Guide and Reference Manual - 29 Sep 2017