PRO POINTER_FREE, POINTER

;+
; NAME:
;    POINTER_FREE
;
; PURPOSE:
;    Free an existing pointer.
;
;    This routine uses pointers if run under IDL5 or higher,
;    and handles if run under IDL4.
;
; CATEGORY:
;    Pointers
;
; CALLING SEQUENCE:
;    POINTER_FREE, POINTER
;
; INPUTS:
;    POINTER    Pointer variable
;
; OPTIONAL INPUTS:
;    None.
;
; INPUT KEYWORD PARAMETERS:
;    None.
;
; OUTPUT KEYWORD PARAMETERS:
;    None.
;
; OUTPUTS:
;    None.
;
; OPTIONAL OUTPUTS:
;    None.
;
; COMMON BLOCKS:
;    None.
;
; SIDE EFFECTS:
;    None.
;
; RESTRICTIONS:
;    POINTER must be a valid pointer variable.
;
;    See also POINTER_CREATE, POINTER_VALID, POINTER_VALUE.
;
; EXAMPLE:
;
; ;Create and then free a pointer
;
; pointer_create, ptr
; help, pointer_valid(ptr)
; pointer_free, ptr
; help, pointer_valid(ptr)
;
; MODIFICATION HISTORY:
; http://cimss.ssec.wisc.edu/~gumley
; $Id: pointer_free.pro,v 1.7 1999/06/18 16:43:46 gumley Exp $
;-

rcs_id = '$Id: pointer_free.pro,v 1.7 1999/06/18 16:43:46 gumley Exp $'

;- Check arguments

if n_params() ne 1 then message, 'Usage: POINTER_FREE, POINTER'
if n_elements(pointer) eq 0 then message, 'Argument POINTER is undefined'

;- Free any valid pointers

version = long(!version.release)
case 1 of
  version ge 5 : begin
    result = size(pointer)
    if result[result[0] + 1] eq 10 then ptr_free, pointer
  end
  else : begin
    for i = 0, n_elements(pointer) - 1 do begin
      if pointer_valid(pointer(i)) then handle_free, pointer(i)
    endfor
  end
endcase

;- Make the pointer variable undefined

null = temporary(pointer)

END