And so, basically, does Go.

Except there is a fairly large difference with interface{}, in that it is typed. interface{} is more like Object in java than void* from C. If you incorrectly cast an interface{} to a type it's not, it will be a runtime error.

Details: http://research.swtch.com/interfaces

> If you incorrectly cast an interface{} to a type it's not, it will be a runtime error.

Sidenote, you may or may not have meant a panic - so i just want to clarify.

Casting an interface to a type incorrectly will not cause a panic/crash, assuming you use the proper syntax.

    // Will panic
    foo := myInterface.(BadType)
    // Will not panic
    foo, ok := myInterface.(BadType)

In the latter, you simply check if `ok` is true or not. If not, the interface value does not implement the given type/interface.

Go doesn't have casts. It has conversions and type assertions. This is a type assertion.