[swift-evolution] Pitch: really_is and really_as operators

[Charles Srstka]

> On Aug 24, 2016, at 7:42 PM, Xiaodi Wu <xiaodi.wu at gmail.com> wrote:
> 
> import Foundation
> 
> let foo: Any = "Hello"
> type(of: foo) == String.self // true
> type(of: foo) == NSString.self // false
> 
> let bar: Any = "Hello" as NSString
> type(of: bar) == String.self // false
> type(of: bar) == NSString.self // true
> 
> Why not this?

Because if you actually try that, it doesn’t work. type(of: bar) == NSString.self actually returns false, not true, because the actual instance belongs to a private subclass of NSString, not NSString itself. type(of: bar) == NSClassFromString(“__NSCFString”) works, but that doesn’t really help us.

Charles
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