register_btraceFeedback.register_btrace : string * bool ref -> unit
Registers a trace variable for a boolean reference.
A call to register_btrace(nm, bref) registers a trace
variable called nm that can take on two different values (0
and 1), which correspond to the state of the boolean variable
bref.
Fails if the given name is already in use as a trace variable.
This function uses register_ftrace to make a boolean
variable appear as an integer value.
Feedback, Feedback.current_trace,
Feedback.register_trace,
Feedback.register_ftrace,
Feedback.set_trace,
Feedback.trace, Feedback.traces