6.2 Metaobject Protocol

SBCL supports a metaobject protocol which is intended to be compatible with AMOP; present exceptions to this (as distinct from current bugs) are:

• the abstract metaobject class is not present in the class hierarchy;
• the standard-object and funcallable-standard-object classes are disjoint;
• compute-effective-method only returns one value, not two;
• the system-supplied :around method for compute-slots specialized on funcallable-standard-class does not respect the requested order from a user-supplied primary method.
• the arguments :declare and :declarations to ensure-generic-function are both accepted, with the leftmost argument defining the declarations to be stored and returned by generic-function-declarations.