// @target: es2015
// https://github.com/Microsoft/TypeScript/issues/16861
class BaseType<T> {
    bar: T
}

class NextType<C extends { someProp: any }, T = C['someProp']> extends BaseType<T> {
    baz: string;
}

class Foo extends NextType<Foo> {
    someProp: {
        test: true
    }
}

const foo = new Foo();
foo.bar.test