how to cast away 'volatile'?

[Matthew Woehlke <mw_triad at users dot sourceforge dot net>]

I have a code snippet that looks roughly like this:

extern void my_free(void* ptr);

int foo()
{
    volatile long * bar;
    ...
    my_free(bar);
}

This generates the warning 'cast discards qualifiers from pointer target 
type' at my_free() (gcc 3.4.3). Other than disabling the flag that 
generates the warning (in general I want these warnings!), how do I 
suppress this? my_free is of course a free() wrapper, i.e. I don't see 
any problems discarding the qualifier at this point. I already tried 
this, which seems like it used to work (I am moving the code from one 
project to another):

    my_free(void*)bar);

...and it doesn't help.

--
Matthew
Emacs is a nice OS - but it lacks a good text editor.
That's why I am using Vim.  -- Anonymous