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register_trace                                              (Feedback)
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register_trace : (string * int ref * int) -> unit

SYNOPSIS
Registers a new tracing variable.

KEYWORDS
Tracing.

DESCRIBE
A call to {register_trace(n, r, m)} registers the integer reference
variable {r} as a tracing variable associated with name {n}.  The
integer {m} is its maximum value.  Its value at the time of
registration is considered its default value, which will be restored
by a call to {reset_trace n} or {reset_traces}.

FAILURE
Fails if there is already a tracing variable registered under the name
given, or if either the maximum value or the value in the reference is
less than zero.

SEEALSO
Feedback, Feedback.register_btrace, Feedback.register_ftrace,
Feedback.reset_trace, Feedback.reset_traces, Feedback.trace,
Feedback.traces.

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