Re: Quick Question: How can I get the GTypeInfo from a GType?

[Ryan McDougall <ryan mcdougall telusplanet net>]

On Thu, 2004-01-08 at 09:04, Owen Taylor wrote:
> On Wed, 2004-01-07 at 22:38, Ryan McDougall wrote:
> > Specifically I want to be able to look up how large the object is, for
> > pointer arithmetic, if only given a GType. Doesn't appear to be any
> > obvious way.
> 
> Can you be more specific about what you are doing? I can't
> think of any reason to do this that wouldn't be entirely
> incorrect and dangerous.
> 
> Regards,
> 					Owen
>  

As I read through the source codes lots of good and bad ideas pop into
my head. Right now I am thinking about implementing an Iterator object
for use in a STL style container system. I think the APIs for GList,
GArray, GTree, etc can be simplified and enriched by using some ideas
from STL's design. Of course C has no easy way to fake C++'s Generic
programming, but there may be yet some stuff that will transfer over.

Aside: How efficient is GValue for faking Generic Programming?

Since pointers are iterators I want to see if I can create
implementations of the iterator models In/Out, Fore/Back, Random Access,
etc via an interface GIterator that has methods (respective to the
above) peek/poke, next/prev, goto, etc. If the iterator doesnt support
some operation (lets say poke, because its a read-only Output Iterator),
then the method is NULL. Basically the implementation for contiguous
memory would be pointer arithmetic on void pointers using the size of
the object. For things like linked lists, and trees, someone would have
to make sure the method points to something like g_list_forward_iter(),
or g_tree_depthfirst_iter(), instead of g_array_iter().

Its all pretty fluid and in my head since Im not sure how good an idea
it is... What do you think?

Cheers,
Ryan