disable_rostime for roscpp

edit

I'm looking for the corresponding api in roscpp of the following rospy api

rospy.init_node('emulation_clock', disable_rostime=True)

i.e. I want to configure disable_rostime for a cpp publisher node publishing a custom clock
when publishing a custom clock, I will have to set use_sim_time to True so other nodes will subscribe to the published /clock topic
however, setting use_sim_time to True also lets my cpp publisher to wait for the /clock - which would be prevented via disable_rostime...however, this seems not to be available in roscpp's

ros::init(argc, argv, "emulation_clock");

(python works, but has high load - so I wanted to implement the clock publisher in roscpp for performance reasons...)