15.16 CLOS/MOP changes
15.16.1 Efficient copying of slot values
The new functions
clos:replace-standard-object allow you to copy slot values from one CLOS instance into another (or make a new copy) very efficiently.
15.16.2 Computing the effective method function
The new MOP generic function
clos:compute-effective-method-function-from-classes is called by LispWorks to compute the effective method function when a generic function is called with required arguments of specified types.
LispWorks Release Notes and Installation Guide - 2 Mar 2015