The R Project SVN R

/* standardGeneric:  uses a pointer to R_standardGeneric, to be

   initialized when the methods package is attached.  When and if the

   methods code is automatically included, the pointer will not be

   needed 

*/

typedef SEXP (*R_stdGen_ptr_t)(SEXP, SEXP);

R_stdGen_ptr_t R_standardGeneric_ptr = 0;

SEXP do_standardGeneric(SEXP call, SEXP op, SEXP args, SEXP env)

{

  SEXP arg, value;

  if(!R_standardGeneric_ptr)

    error("Using standardGeneric before the methods package has been attached");

  checkArity(op, args);

  PROTECT(arg = CAR(args));

  value = (*R_standardGeneric_ptr)(arg, env);

  UNPROTECT(1);

  return value;

}