array.c:668
VALUE
rb_ary_to_ary(obj)
    VALUE obj;
{
    if (TYPE(obj) == T_ARRAY) {
	return obj;
    }
    if (rb_respond_to(obj, rb_intern("to_ary"))) {
	return rb_convert_type(obj, T_ARRAY, "Array", "to_ary");
    }
    return rb_ary_new3(1, obj);
}
