ViewRepresentable.swift

protocol ViewRepresentable: ViewModelTypeErasedViewRepresentable {
    associatedtype ViewModelType: ViewModel
    
    var model: ViewModelType! { get set }
    
    func bindWithModel()
}

protocol ViewModelTypeErasedViewRepresentable: class {
    var typeErasedViewModel: ViewModel? { get set }
}

extension ViewRepresentable {
    var typeErasedViewModel: ViewModel? {
        get { model }
        set { model = (newValue as! Self.ViewModelType) }
    }
}

extension ViewRepresentable {
    func setupViewModel() {
        model?.setup()
        bindWithModel()
    }
}