+void
+ly_wrong_smob_arg (bool pred (SCM), SCM var, int number, const char *fun)
+{
+ string type = predicate_to_typename ((void *) pred);
+ if (pred (var))
+ {
+ // Uh oh. unsmob<T> delivered 0, yet
+ // unsmob<T> delivers true. This means that unsmob<T> is a
+ // matching check from a base class of T, but var is of an
+ // incompatible derived type.
+ type = string (_ ("Wrong kind of ")).append (type);
+ }
+ scm_wrong_type_arg_msg (mangle_cxx_identifier (fun).c_str (),
+ number, var, type.c_str ());
+}
+
+