description

# castFrom<S, T> method Null safety

Queue<T> castFrom <S, T>(

1. Queue<S> source

)
override

Adapts `source` to be a `Queue<T>`.

Any time the queue would produce an element that is not a `T`, the element access will throw.

Any time a `T` value is attempted stored into the adapted queue, the store will throw unless the value is also an instance of `S`.

If all accessed elements of `source` are actually instances of `T`, and if all elements stored into the returned queue are actually instance of `S`, then the returned queue can be used as a `Queue<T>`.

## Implementation

    static Queue<T> castFrom<S, T>(Queue<S> source) => CastQueue<S, T>(source);