Call user_class->meta in fewer places, with the eventual goal of allowing the user to rename or exclude ->meta altogether. Instead uses Class::MOP::class_of. (Sartak)
Class::MOP
New class_of function that should be used to retrieve a metaclass. This is unlike get_metaclass_by_name in that it accepts instances, not just class names. (Sartak)
Class::MOP
load_first_existing_class didn't actually load the first existing class; instead, it loaded the first existing and compiling class. It now throws an error if a class exists (in @INC) but fails to compile. (hdp)
Class::MOP
Class::MOP::Class
we had some semi-buggy code that purported to provide a HAS_ISAREV based on whether mro had get_isarev (due to an oversight, it always returned 1). Since mro and MRO::Compat have always had get_isarev, HAS_ISAREV was pointless. This insight simplified the subclasses method by deleting the pure-perl fallback. HAS_ISAREV is now deprecated. (Sartak)