serviceState.ts

export function ServiceState<G>(): new () => { value?: G, set(type: G): G }
export function ServiceState<G>(type: G): new () => { value: G, set(type: G): G }
export function ServiceState<G>(type?: G) {
    return class ServiceState {
        value: G | undefined

        constructor() {
            this.value = type
        }

        set(type: G) {
            this.value = type
            return type
        }
    }
}