Tucker Taft a �crit dans le message ...
>=:-) Vincent (vb@bruker.fr) wrote:
>: What's the best way ?
>
>An "out" parameter is always preferable to an "access" parameter, in my
view.
>
>Use an "access" parameter only if you need an access value when
>inside the called subprogram for some reason.  This usually only
>happens when interfacing to some other language, or some preexisting
>subsystem of some sort.
>


Ok but be carefull. With an access type you can't pass a null pointer. This
is a big problem.
In fact if you look at the Win32 C API or UNIX C library you'll find that it
is often possible
to pass a null pointer to some parameters to say : "ignore this one, I don't
care for the result" !

So, in many many cases it is better to use an access type (not an access
formal parameter)
when interfacing with some other language.

Pascal.

PS : The Win32Ada binding is full of access parameters that are just wrong !