Function

Summary

Returns a pointer to a specified element in an array.

Package

fli

Signature

foreign-array-pointer array &rest subscripts => pointer

Arguments

array

A FLI array or a pointer to a FLI array.

subscripts

A list of valid array indices for array.

Values

pointer

A pointer to the element at position subscripts in array.

Description

The function foreign-array-pointer returns a pointer to a specified element in an array. The value pointed to can then be obtained by dereferencing the pointer returned, or set to a specific value using (setf dereference).

Examples

In this example a 3 by 2 array of integers is created, and a pointer to the element at position 2 0 is returned using foreign-array-pointer.

(setq array1 (fli:allocate-foreign-object 

              :type '(:c-array :int 3 2)))

(setq array-ptr (fli:foreign-array-pointer array1 2 0))

The (setf dereference) function can now be used to set the value pointed to by array-ptr.

(setf (fli:dereference array-ptr) 42)

See also

foreign-aref
foreign-array-dimensions
foreign-array-element-type