Playground code for the article

TypeErasure.swift

import Foundation

protocol CustomProtocol {
    associatedtype AssociatedType
    func foo(argument: AssociatedType)
}

//let array = [CustomProtocol]() // Gives error: Protocol 'CustomProtocol' can only be used as a generic constraint because it has Self or associated type requirements

public struct AnyCustomProtocol<T>: CustomProtocol {
    func bar() -> T {
        fatalError("Needs implementation")
    }
    func foo(argument: T) {
        
    }
}

let array = [AnyCustomProtocol<Any>]()