[Boost-users] [fusion] fused_procedure vs. fused_function_object

It appears the only difference is that fused_procedure has a void result type regardless of the adapted function's result type, where as fused_function_object's return type is that of the adapted function, is that true? What are the advantages of using fused_procedure, as it appears in my usage that fused_function_object can be used in place of fused_procedure? Awesome lib by the way! Thanks, Jeff