[R] field of two possible types in reference classes

[Martin Ivanov]

 Dear R users,
I am learning the OOP programming with R, in particular with reference classes.

If I have a class, e.g.

myclass <- setRefClass(class="myclass", fields=list(x="numeric"));

I know that if I do not want to set any class for x, I can just type fields=list(x="ANY"). But what if
I want to allow x to be of two possible classes, e.g. "numeric" or "logical". They do not inherit from each other, so setting the one and passing the other class results in an error.

Any suggestions will be appreciated.

Best regards,

Martin