cloning methods.c

VALUE
rb_singleton_class_clone(VALUE obj)
{
    VALUE klass = RBASIC(obj)->klass;

    if (!FL_TEST(klass, FL_SINGLETON))
	return klass;
    else {
	struct clone_method_data data;
	/* copy singleton(unnamed) class */
	VALUE clone = class_alloc((RBASIC(klass)->flags & ~(FL_MARK)), 0);

	if (BUILTIN_TYPE(obj) == T_CLASS) {
	    RBASIC(clone)->klass = (VALUE)clone;
	}
	else {
	    RBASIC(clone)->klass = rb_singleton_class_clone(klass);
	}

	RCLASS_SUPER(clone) = RCLASS_SUPER(klass);
	if (RCLASS_IV_TBL(klass)) {
	    RCLASS_IV_TBL(clone) = st_copy(RCLASS_IV_TBL(klass));
	}
	RCLASS_M_TBL(clone) = st_init_numtable();
	data.tbl = RCLASS_M_TBL(clone);
	data.klass = (VALUE)clone;
	st_foreach(RCLASS_M_TBL(klass), clone_method,
		   (st_data_t)&data);
	rb_singleton_class_attached(RBASIC(clone)->klass, (VALUE)clone);
	FL_SET(clone, FL_SINGLETON);
	return (VALUE)clone;
    }
}