Working with Automation datatypes - example

Based on a previous message thread with Chris Double, I have put 
together an example that works for me. No memory access violations, 
no hangs. Note the prototype; 

HRESULT LoadTypeLib( 
  const OLECHAR FAR*  szFile,       
  ITypeLib FAR* FAR*  pptlib  
);

So I declare (ITYPELIB *) because '&' is used implicitly when the 
argument is passed to LoadTypeLib. What is not intuitive to me is 
that when I go to use the value (ptlb), I actually deference the 
pointer twice, instead of once.

What I plan to do is make some wrapper classes of my own that will 
hide some of the less interesting details of how this is actually 
done. I have examined Com-type-libs.lisp but those structures still 
require a fair amount of FFI knowledge in order to use them.

;;;
;;; Wayne Rogers
;;; short example. Use the path of some known good TypeLib 
resource ;;;like c:\\winnt\\\system32\\stdole2.tlb or an ActiveX dll.

(load (concatenate 'string *cormanlisp-directory* "modules\\com-type-
libs.lisp"))

(in-package :win32)

(defmacro create-new (typename)
    `(malloc (sizeof ',typename)))

(defun ListTypes (szpath)                
    (let ((ptlib (create-new (ITypelib *)))
           tlib
          (name (create-new Bstr))
          (doc  (create-new Bstr)))
        (if (= S_OK (LoadTypeLib (lisp-string-to-unicode szPath) 
ptlib))
            (progn
                (setf tlib (cref ((ITypeLib *) *) ptlib 0))
                (format t "~D typedefinitions~%" (ItypeLib-
GetTypeinfoCount tlib))
                (dotimes (n (ItypeLib-GetTypeinfoCount 
tlib))                    
                    (ItypeLib-GetDocumentation tlib n name doc 
cl::c_null cl::c_null)
                    (unless (cpointer-null (cref (BSTR *) name 0))
                        (format t "~A~%" (unicode-to-lisp-string 
(cref (Bstr *) name 0)))))))))

;; one of my COM servers
(ListTypes "c:\\winnt\\\system32\\stdole2.tlb")





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