==== tests/cases/compiler/genericTypeAssertions6.ts (3 errors) ====
    class A<T,U> {
        constructor(x) {
            var y = <T>x;
            var z = <U>x;
        }
    
        f(x: T, y: U) {
            x = <T>y;
                ~~~~
!!! Neither type 'T' nor type 'U' is assignable to the other.
            y = <U>x;
                ~~~~
!!! Neither type 'U' nor type 'T' is assignable to the other.
        }
    }
    
    class B<T extends Date, U extends Date> extends A<T, U> {
        g(x: T) {
            var a: Date = x;
            var b = <Date>x;
            var c = <T>new Date();
            var d = <U>new Date();
            var e = <T><U>new Date();
                    ~~~~~~~~~~~~~~~~
!!! Neither type 'T' nor type 'U' is assignable to the other.
        }
    }
    
    var b: B<Date, Date>;
    var c: A<Date, Date> = <A<Date, Date>>b;