Is it possible to replicate Swifts automatic numeric value bridging to Foundation (NSNumber) for (U)Int8/16/32/64 types?

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Question

  • Is it possible to replicate Swifts numeric value bridging to Foundation:s NSNumber reference type, for e.g. Int32, UInt32, Int64 and UInt64 types? Specifically, replicating the automatic by-assignment bridging covered below.

Intended example usage of such a solution:

let foo : Int64 = 42
let bar : NSNumber = foo
    /* Currently, as expected, error:
       cannot convert value of type 'Int64' to specified type 'NSNumber */

Background

Some of the native Swift number (value) types can be automatically bridged to NSNumber (reference) type:

Instances of the Swift numeric structure types, such as Int, UInt, Float, Double, and Bool, cannot be represented by the AnyObject type, because AnyObject only represents instances of a class type. However, when bridging to Foundation is enabled, Swift numeric values can be assigned to constants and variables of AnyObject type as bridged instances of the NSNumber class.

...

Swift automatically bridges certain native number types, such as Int and Float, to NSNumber. This bridging lets you create an NSNumber from one of these types:

let n = 42
let m: NSNumber = n

It also allows you to pass a value of type Int, for example, to an argument expecting an NSNumber. ...

All of the following types are automatically bridged to NSNumber:

- Int
- UInt
- Float
- Double
- Bool

From Interoperability - Working with Cocoa Data Types - Numbers.

So why attempt to replicate this for the IntXX/UIntXX types?

Primarily: Curiosity, sparked by seeing some questions recently with underlying problems covering confusion over why an Int value type seemingly can be represented by an AnyObject (reference) variable, whereas e.g. Int64, cannot; which is naturally explained by the bridging covered above. To pick a few:

None of Q&A:s above mentions, however, the possibility of actually implementing such automatic bridging to AnyObject (NSNumber) from the non-bridged types Int64, UInt16 and so on. The answers in these threads rather focuses (correctly) on explaining why AnyObject cannot hold value types, and how the IntXX/UIntXX types are not bridged for automatic conversion to the underlying Foundation types of the former.

Secondarily: For applications running at both 32-bit and 64-bit architectures, there are some narrow use cases—using Swift native number types implicitly converted to AnyObject, in some context—where using e.g. Int32 or Int64 type would be preferred over Int. One (somewhat) such example:

swift2 nsnumber swift
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