I don't understand why this piece of Objective-C code:

```
id object = nil;
NSEnumerator *enumerator = ...;
while ((object = [enumerator nextObject])) {...}

```

can't be translated in Swift like this:

```
var key:AnyObject!
let enumerator:NSEnumerator = myNSDictionary.keyEnumerator()    
while ( (object = enumerator.nextObject()) ) {...}

```

I have this error :

> 
> Type '()' does not conform to protocol 'BooleanType'
> 
> 
>