Function

Summary

Returns a copy of a pointer object.

Package

fli

Signature

copy-pointer pointer &key type pointer-type => copy

Arguments

pointer

A pointer to copy.

type

The type of the object pointer to by pointer .

pointer-type

The type of pointer .

Values

copy

A copy of pointer .

Description

The function copy-pointer returns a copy of pointer .

Example

In the following example a pointer point1 is created, pointing to a :char type. The variable point2 is set equal to point1 using setq , whereas point3 is set using copy-pointer . When point1 is changed using incf-pointer , point2 changes as well, but point3 remains the same.

(setq point1 (fli:allocate-foreign-object :type 

                                          :char))

(setq point2 point1) (setq point3 (fli:copy-pointer point1)) (fli:incf-pointer point1)

The results of this can be seen by evaluating point1 , point2 , and point3 .

The reason for this behavior is that point1 and point2 are Lisp variables containing the same foreign object; a pointer to a char , whereas point3 contains a copy of the foreign pointer object.

See also

make-pointer
Copying pointers