I'm attempting to create a class with a generic parameter that extends type boolean. I've tried to make this generic parameter accessible at runtime by assigning it to a property like so:
class Example<T extends boolean> {
foo: T = true;
}
The base class declaration works, but the line initializing foo yields the error:
Type 'boolean' is not assignable to type 'T'.
'boolean' is assignable to the constraint of type 'T', but 'T' could be instantiated with a different subtype of constraint 'boolean'.
This doesn't make much sense to me. What other type could T be that extends but does not fall under true | false? Why does the possibility that it could be another type prevent it from being initialized as a boolean?
new Example<false>().foobe? According to the types it'sfalse, but according to your initializer, it'strue. That's the problem and why you can't do it.