Is there some workaround for this? When `a` is a var I get this error: ```Type of 'a' doesn't match ...

# getting-started

[zt]

Is there some workaround for this? When a is a var I get this error:

Type of 'a' doesn't match the type of the overridden 'var' property 'var a: Letter' defined in '/Base'

It doesn't occur when it's a val

open class Base {
    open var a: Letter = Letter()
}

class BaseExt : Base() {
    override var a: A = A()
}

open class Letter

class A : Letter()

[Joffrey]

A is a subtype of Letter, so if it's a val all is good. The problem when it's a var is that someone could assign any subtype of Letter to a, which would break instances of `BaseExt`:

val ext: Base = BaseExt()
ext.a = Letter() // respects the interface of Base, yet shouldn't be allowed for BaseExt