This could fail, since Any is more broad that AnyObject is, so the casting could fail.

I do not see how this can cause problems. @yaroslavyaroslav Could you please give more explanation/examples?

It's said that all classes implicitly conform to AnyObject but we're able to cast structs as well so maybe that part about structs (or to be specific value types is confusing).

Did some research and found that casting value types to AnyObject produces a wrapper of type __SwiftValue. And here is the __SwiftValue. Look at the docs on line 13.

Lol, why did they do that? Like now there's completely no difference between Any and AnyObject isn't it? If so, i agree that this would not fall, but i still suggest to make that extension more consistent, using either Any or AnyObject in whole method.

There is still some difference when it comes to casting back to the original type. I cannot explain that in detail but for example if we cast UInt64(1) to AnyObject and try to use it as if let bool = uint64AsAnyObject as? Bool it will successfully cast to Bool. But if you cast it to Any instead it will cast back only as UInt64.

but for example if we cast UInt64(1) to AnyObject and try to use it as if let bool = uint64AsAnyObject as? Bool it will successfully cast to Bool. But if you cast it to Any instead it will cast back only as UInt64.

Actually I'd consider this as a bug of those thing that is casting to AnyObject for Objective-C environment. But I don't sure though.

1. This extension doesn't apply to [Any] but it should. As a solution where clause can be removed;
2. I'd suggest renaming the function to toAnyObjectArray;
3. Why self.map { ... } and not just as [AnyObject]?

This is the suggested update:

/// Transforms into `[AnyObject]`
extension Array {
    func toAnyObjectArray() -> [AnyObject] {
        self as [AnyObject]
    }
}