Trouble with casting let list = list as? List<Object>

[ChangSung kim]

Hi 

I'm using RealmSwift version 0.97.0 

1. When I use under the code, result value is unexpected. here is the code.

class BDRUser:Object {

...
}

    func change(list:AnyObject) -> Bool {

        if let list = list as? List {

            return true

        } else {

            return false

        }

    }

    

    let list = List<BDRUser>()

    list.append(BDRUser())

    print(change(list))

-- 

print value is false 

I expected the printing value was true but  it didn't 

can you know me how can I fix it ? 

2.  here is another code 

        let list = List<BDRUser>()

        list.append(BDRUser())

        let v = list as? List<Object>

        print(v)

the result is 'nil' 

I wonder why type casting doesn't work well from List<BDRUser> to List<Object> ? That is always fail 

so could you fix it though? 

Thanks ! 

[Marius Rackwitz]

Hey,

what you're trying to achieve is not supported with Swift.
Collection types in Swift are not covariant.
The compiler should warn you, that what you're trying to do will never succeed.
You can use instead map:
let v = list.map { $0 as Object }

Best!

--
Marius Rackwitz
iOS Product Engineer

{#HS:162783134-2718#}

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