Add `invalid_stream` for initializing stream<T>
Add `invalid_stream` for initializing stream<T>

actor-framework/actor-framework,DavadDi/actor-framework,actor-framework/actor-framework,actor-framework/actor-framework,actor-framework/actor-framework,DavadDi/actor-framework,DavadDi/actor-framework,DavadDi/actor-framework