I am trying to achieve the automatic/dynamic cast in the fourth line below:

```
let a = 1 // type: int
let b = box a // type: obj
b.GetType() // System.Int32, so it is perfectly aware what it is!
let c = unbox b  // fails....

```

The following would would work in the final line above BUT would require me to know and explicitly mark ahead-of-time the primitive/value type that I am working with (which I am trying to avoid):

```
let c1:int = unbox b
let c2 = b :?> int 

```