[#BloombergLP-ball-MultiplexObserver-registerObserver]
= xref:BloombergLP.adoc[BloombergLP]::xref:BloombergLP/ball.adoc[ball]::xref:BloombergLP/ball/MultiplexObserver.adoc[MultiplexObserver]::registerObserver
:relfileprefix: ../../../
:mrdocs:

Add the specified `observer` to the registry of this multiplexing observer. Return 0 if `observer` is non‐null and was not already registered with this multiplexing observer, and a non‐zero value (with no effect) otherwise. Henceforth, this multiplexing observer will forward each record it receives through its `publish` method, including the record's context, to the `publish` method of `observer`, until `observer` is deregistered. The behavior is undefined unless `observer` remains valid until it is deregistered from this multiplexing observer or until this observer is destroyed.

== Synopsis

Declared in `<ball_multiplexobserver.h>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
int
registerObserver(xref:BloombergLP/ball/Observer.adoc[Observer]* observer);
----


[.small]#Created with https://www.mrdocs.com[MrDocs]#