rib: route addition and removal signals

refs: #3818

Change-Id: Ic47afeba4b4133a2092b26ecd49adbaac0505781
diff --git a/rib/rib-entry.hpp b/rib/rib-entry.hpp
index c3c5b4c..d55d3f1 100644
--- a/rib/rib-entry.hpp
+++ b/rib/rib-entry.hpp
@@ -72,9 +72,12 @@
   /** \brief inserts a new route into the entry's route list
    *  If another route already exists with the same faceId and origin,
    *  the new route is not inserted.
-   *  \return{ true if the route is inserted, false otherwise }
+   *  \return a pair, whose first element is the iterator to the newly
+   *  inserted element if the insert succeeds and to the
+   *  previously-existing element otherwise, and whose second element
+   *  is true if the insert succeeds and false otherwise.
    */
-  bool
+  std::pair<RibEntry::iterator, bool>
   insertRoute(const Route& route);
 
   /** \brief erases a Route with the same faceId and origin