[Spice-devel] [PATCH 09/14] server: make cursor channel private

[Jonathon Jongsma]

On Fri, 2015-10-23 at 10:29 -0400, Frediano Ziglio wrote:

> >  
> > +#define RED_CHANNEL(Channel) ((RedChannel *)(Channel))
> > +
> 
> I really don't like these kind of macros, they are really type
> unsafe,
> what about
> 
>   void *p = malloc(50);
> 
>   red_channel_client_disconnect(RED_CHANNEL(p));
> 
> the more explicit
> 
>   void *p = malloc(50);
> 
>   red_channel_client_disconnect((RedChannel*) p);
> 
> make it more explicit that we are doing something dangerous.
> 
> It would be much better to define a public structure like
> 
> struct CursorChannel {
>    CommonChannel common;
> };
> 
> and a private one (in cursor-channel.c) like
> 
> struct CursorChannel {
>    CommonChannel common;
>    ... any field needed ...
> }
> 
> and define the macro as
> 
> #define RED_CHANNEL(Channel) (&(Channel)->common.base)
> 


But this just sets things up for the future conversion to GObject. When
RedChannel is derived from GObject, RED_CHANNEL() will be the standard
way to cast in a relatively typesafe manner.

Jonathon