generics4NoError.ts(1,22): error TS2564: Property 'x' has no initializer and is not definitely assigned in the constructor.


==== generics4NoError.ts (1 errors) ====
    class C<T> { private x: T; }
                         ~
!!! error TS2564: Property 'x' has no initializer and is not definitely assigned in the constructor.
    interface X { f(): string; }
    interface Y { f(): boolean; }
    var a: C<X>;
    var b: C<Y>;
    