Re: g_(s)list_data()

[Derek Simkowiak <dereks realloc net>]

-> while (list)
-> {
->     Foo *foo = g_list_data(Foo *, list);
->     do_something(foo->obj);
->     list = g_list_next(list);
-> }
-> 
-> 	Which is very nice to read.

	I disagree that this is nice to read.  I'd prefer to just see the
typecast -- at least then a new user will know what's going on (instead of
needing to lookup yet another macro, especially one that doesn't exist
in any of the current code).

->  Face it, the cast will be explicitly typed in 90% of cases (1%
-> really want a gpointer, and the other 9% are GTK_FOO(list->data)
-> calls).

	I agree that the typecasts are very common.  I disagree that a
macro is cleaner than a typecast.

-> What do folks think?  This can, of course, work for GSList too (and any
-> other ->data structs I've forgotten).

	It would need to follow the "object-like" Glib naming convention
of

g_thing_action(GThing *thing, ... )

	...that is, the first argument of your g_list_data() should be a
GList*.  If anything, it would need to be g_list_data(GList *list,
Datatype*).

	Although g_list_next() exists, it has been agreed that there is
way too much code that directly accesses list->next to deprecate that kind
of peeking.  In short, even if list->next was meant to be private, through
real-world practice it has become public.  And since list->data is already
public, there is no need for g_list_data().

	As a frequent Glib user, if g_list_data() gets added, I will still
use list->data in all my code.  Sorry  :)


Derek Simkowiak
dereks at realloc dot net