Bindingの初期値をイニシャライザーで設定する
enum Mode { case none case alert case success case retry } @Binding var mode: Mode init(_ mode: Binding< Mode > = .constant(.none)) { self.mode = mode }
enum Mode { case none case alert case success case retry } @Binding var mode: Mode init(_ mode: Binding< Mode > = .constant(.none)) { self.mode = mode }