Signal.opAssign - multiple declarations

Function Signal.opAssign

replace all previously assigned listeners with new one (if null passed, remove all listeners)

final void opAssign(
  Signal.slot_t listener
);

final void opAssign(
  T1 listener
);

Function Signal.opAssign

replace all previously assigned listeners with new one (if null passed, remove all listeners)

final void opAssign(
  Signal.slot_t listener
);