Thank you to |3b| on #sbcl for linking me to this report.
The setf expander defined for FOREIGN-SLOT-VALUE calls GET-SETF-EXPANDER on the PTR form. The setf expanders for MEM-REF and MEM-AREF do the same.
I am unsure on why the PTR argument needs to be a place in any of the above.
Thank you to |3b| on #sbcl for linking me to this report.
The setf expander defined for FOREIGN-SLOT-VALUE calls GET-SETF-EXPANDER on the PTR form. The setf expanders for MEM-REF and MEM-AREF do the same.
I am unsure on why the PTR argument needs to be a place in any of the above.