TypeScript Version: 2.8.0-dev.20180308

Code

interface Instance {
  foo: number;
}

interface Constructor<I extends Instance> {
  new(): I;
}

function MixIn<T extends Instance>(Base: Constructor<T>) {
  return class extends Base {
    
  }
}

Expected behavior:
That my MixIn accepts that construct so that I can define a extended interface T with properties which are available at a instance of the MixIn class.

Actual behavior:

error TS2509: Base constructor return type 'T' is not a class or interface type.

It works when I remove the generic type at the function MixIn (like function MixIn(Base: Constructor<Instance>)) .

Related Issues:
I found old issues like #8853 or #4890
Because that I thought it should work.