Re: less mixing of object and function pointers

[Eric Blake]

Hi Ralf,

From: Ralf Wildenhues
> This rather mechanical patch fixes one half of the issue of mixing
> pointers to data and pointers to functions, by changing the set of
> callback functions to using two pointers to void and one pointer to
> a function type (since we only need one function signature, there
> is no problem with just using that; otherwise, we could still cast
> between different function types).
> 
> Since we now have even more unused arguments, I decided to add a macro
> LT__UNUSED to make GCC emit less warnings, and used that throughout
> libltdl.
> 
> OK to apply?  Tested on GNU/Linux, where libltdl now passes
>   make CFLAGS='-W -Wall -Werror'
> 
> for me.  (But I'm fixing this now only because it will make my next
> bugfix easier.)

Looks good to me.  I suppose an alternative would have been
declaring a union of an object and function pointer, and using that
union as the parameter in the callbacks, to avoid the number of
unused parameters, but I think your approach is a little cleaner.

-- 
Eric Blake