mrb_define_singleton_method_id(mrb_state *mrb, struct RObject *o, mrb_sym name, mrb_func_t func, mrb_aspec aspec)
{
  prepare_singleton_class(mrb, (struct RBasic*)o);
  mrb_define_method_id(mrb, o->c, name, func, aspec);
}
mrb_define_singleton_method_id(mrb_state *mrb, struct RObject *o, mrb_sym name, mrb_func_t func, mrb_aspec aspec)
{
  prepare_singleton_class(mrb, (struct RBasic*)o);
  mrb_define_method_id(mrb, o->c, name, func, aspec);
}