Define protocol with property of Any type?

Using Swift
1

Is is possible to define a protocol with a type that can hold Any type of value?

i.e.

protocol MyProtocol {
    var foo: Any? {get set}
}

struct A : MyProtocol {
    var foo : String?
}

struct C : MyProtocol {
    var foo : Int?
}

Basically, I just need implimenting structs to have the property, regardless of type.

If I do this, I can create the protocol, but get an error from the structs that they are do not conform to the protocol.

2

You should either specify an associated type that the structs will use (preferably)

protocol MyProtocol {
  associatedtype Foo
  var foo: Foo? {get set}
}

struct A : MyProtocol {
  var foo : String?
}

struct C : MyProtocol {
  var foo : Int?
}

or use Any instead of concrete types in the structs as well:

protocol MyProtocol {
  var foo: Any? {get set}
}

struct A : MyProtocol {
  var foo : Any?
}

struct C : MyProtocol {
  var foo : Any?
}
1 Like
3

Thank you! It looks like associatedTypes are exactly what I was looking for. Reading up on them now.

1 Like