Conforming to a protocol and also having a property with the type of the protocol in the same struct-CodePudding

I have the following struct:

struct ImageSlider: CodableComponent {
    let slides: [CodableComponent]?
}

which conforms to CodableComponent

protocol Component {

}

typealias CodableComponent = Component & Decodable

But I get the following error:

Type 'ImageSlider' does not conform to protocol 'Decodable'

As soon as I remove the conformance to CodableComponent in ImageSlider, like the following:

struct ImageSlider {
    let slides: [CodableComponent]?
}

The error is gone.

I'm not sure what exactly is happening here, why I cannot conform to a protocol and also have a property of the same type?

Would be appreciated if someone could shed some light on this case.

CodePudding user response：

You have to implement Decodable protocol, for example:

struct ImageSlider: CodableComponent {
    let slides: [CodableComponent]?
    
    init(from decoder: Decoder) throws {
        // decode values here
    }
}

CodePudding user response：

So, I found out that there are 2 ways to address this issue. The first one is using init(from:) as you can see in the comments and other answers. The other one is by using "existential any" in Swift 5.6

struct ImageSlider: any CodableComponent {
    let slides: [any CodableComponent]
}