Feedback on gobject-introspection: Casting to and from GIBaseInfo*

I've been trying out the new g-i API in GLib. Compared with g-i 1.0 there is a lot more manual casting involved.

Previously, all of the GIFooInfo types were aliases of GIBaseInfo, so they could be used interchangeably. Now they are aliases of distinct, opaque structs.

This requires a lot more manual casting in order to use the API. For example:

GIFunctionInfo *func_info;
func_info = (GIFunctionInfo *) gi_repository_get_info (repo, namespace, idx);
g_print("%s\n", gi_base_info_get_name ((GIBaseInfo *) func_info);
gi_callable_info_invoke ((GICallableInfo *) func_info, ...);
g_clear_pointer ((GIBaseInfo **) &func_info, gi_base_info_unref);

The old way:

GIFunctionInfo *func_info;
func_info = g_irepository_get_info (repo, namespace, idx);
g_print("%s\n", g_base_info_get_name (func_info);
g_callable_info_invoke (func_info, ...);
g_clear_pointer (&func_info, g_base_info_unref);

It would be nice to at least have casting macros like GObject types do, with runtime checks when casting to a more specific info type. That is, GI_BASE_INFO() as well as pairs of GI_FUNCTION_INFO()/GI_IS_FUNCTION_INFO() for each info type.

Even nicer would be to allow any info type pointer to decay to GIBaseInfo * automatically, but I'm not sure if that's possible without the types being aliases of each other.