sizeof-fobject

Arguments: ftype

This function returns the size of an object of the given foreign type. The argument ftype can be an ftype or a name of a foreign type or certain kinds of fobjects. (fobjects are the objects that result from a call to ff:allocate-fobject and related functions.) Only fobjects of allocation type :foreign or :foreign-static-gc can be arguments to this function. fobjects of allocation types :lisp, :lisp-short, :c, and :aligned cannot be arguments. The allocation type is defined when the object is created. Note that objects of allocation type :lisp have their own lisp types, and thus do not imply a foreign-type; and objects of :c allocation are just integers, and thus again do not imply a foreign-type.

The size only includes the data bytes and not any overhead bytes needed by lisp.

Example

cl-user(1): (ff:def-foreign-type point (:struct (x :int) (y :int)))
#<foreign-functions::foreign-structure point>
cl-user(2): (setq obj (ff:allocate-fobject 'point :foreign-static-gc))
#<foreign object of class point>
cl-user(3): (ff:sizeof-fobject 'point)
8
cl-user(4): (ff:sizeof-fobject (ff:get-foreign-type 'point))
8
cl-user(5): (ff:sizeof-fobject obj)
8
cl-user(6): 

See ftype.htm for information on foreign types in Allegro CL and foreign-functions.htm for general information on foreign functions in Allegro CL.

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This page was not revised from the 10.0 page.
Created 2019.8.20.