I am using CFFI with ECL to interface to a C++ library, which has a C++ class with a data member of type 'cl_object'. Simplified, my C++ code is: class LispObject { public: cl_object object; }; extern "C" cl_object getObject(LispObject* lo) { return lo->object; } extern "C" void setObject(LispObject* lo, cl_object clo) { lo->object = clo; } The full code is: https://common-lisp.net/viewvc/clive/trunk/src/extensions/corral/CliveCorral/LispObjectImpl.hpp?revision=149&view=markup#l59 Can I somehow declare the 'cl_object' type for the 'getValue()' and 'setValue()' functions using CFFI 'defcfun' to get and set ECL objects? Is there a technique using the lower-level FFI? I am looking for a way to do this without compiling C code embedded in Lisp, which I am aware ECL can do. Thank you for any ideas! -- Stewart Milberger Kavalogic, Inc.