+ (format stream "};~2%")
+ (format stream "/* Union of equivalent superclass vtables. */~@
+ union ~A {~@
+ ~:{ struct ~A ~A;~%~}~
+ };~2%"
+ (vtable-union-tag chain-tail chain-head)
+
+ ;; As for the ichain union, make sure the most specific
+ ;; class is first.
+ (mapcar (lambda (super)
+ (list (vtable-struct-tag super chain-head)
+ (sod-class-nickname super)))
+ (sod-class-chain chain-tail))))))