with-foreign-object - CFFI User Manual

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with-foreign-object, with-foreign-objects

Syntax

— Macro: with-foreign-object (var type &optional count) &body body

— Macro: with-foreign-objects (bindings) &body body

bindings ::= {(var type &optional count)}*

Arguments and Values

var: A symbol.
type: A foreign type, evaluated.
count: An integer.

Description

The macros with-foreign-object and with-foreign-objects bind var to a pointer to count newly allocated objects of type type during body. The buffer has dynamic extent and may be stack allocated if supported by the host Lisp.

Examples

  CFFI> (with-foreign-object (array :int 10)
          (dotimes (i 10)
            (setf (mem-aref array :int i) (random 100)))
          (loop for i below 10
                collect (mem-aref array :int i)))
  => (22 7 22 52 69 1 46 93 90 65)

See Also