# @Phil closest that can work for you is :
type
  AppConfig = object of RootObj

  AdwAppConfig = object of AppConfig

  AppContext[T: AppConfig | AdwAppConfig] = object
    config: T



let x = AppContext[AdwAppConfig](config: AdwAppConfig())
# may or may not be satisfastory, my attempts to make this work indicate either i
# have a skill issue or Nim cannot make use of inheritance the way you're trying
# to use it