----------------------------------------------------------------------
register_btrace                                             (Feedback)
----------------------------------------------------------------------
Feedback.register_btrace : string * bool ref -> unit

SYNOPSIS
Registers a trace variable for a boolean reference.

KEYWORDS
tracing

LIBRARY
Feedback

DESCRIBE
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}.

FAILURE
Fails if the given name is already in use as a trace variable.



COMMENTS
This function uses {register_ftrace} to make a boolean variable appear
as an integer value.

SEEALSO
Feedback, Feedback.current_trace, Feedback.register_trace,
Feedback.register_ftrace, Feedback.set_trace, Feedback.trace,
Feedback.traces.

----------------------------------------------------------------------