Minor fixes for #93 (#143)

include/message_filters/sync_policies/approximate_time.hpp

@@ -74,9 +74,9 @@ struct ApproximateTime : public PolicyBase<Ms...>
     , pivot_(NO_PIVOT)
     , max_interval_duration_(rclcpp::Duration(std::numeric_limits<int32_t>::max(), 999999999))
     , age_penalty_(0.1)
-    , has_dropped_messages_(9, false)
-    , inter_message_lower_bounds_(9, rclcpp::Duration(0, 0))
-    , warned_about_incorrect_bound_(9, false)
+    , has_dropped_messages_(N_MESSAGES, false)
+    , inter_message_lower_bounds_(N_MESSAGES, rclcpp::Duration(0, 0))
+    , warned_about_incorrect_bound_(N_MESSAGES, false)
   {
     // The synchronizer will tend to drop many messages with a queue size of 1.
     // At least 2 is recommended.

include/message_filters/sync_policies/latest_time.hpp

@@ -27,9 +27,9 @@
 // POSSIBILITY OF SUCH DAMAGE.
 
 /**
- * \brief Synchronizes up to 9 messages by their rates with upsampling via zero-order-hold.
+ * \brief Synchronizes up to N messages by their rates with upsampling via zero-order-hold.
  *
- * LatestTime policy synchronizes up to 9 incoming channels by the rates they are received.
+ * LatestTime policy synchronizes up to N incoming channels by the rates they are received.
  * The callback with all the messages will be triggered whenever the fastest message is received.
  * The slower messages will be repeated at the rate of the fastest message and will be updated
  * whenever a new one is received. This is essentially an upsampling of slower messages using a
@@ -375,7 +375,7 @@ struct LatestTime : public PolicyBase<M...>
 
   std::vector<RateConfig> rate_configs_;
 
-  const int NO_PIVOT{9};
+  const int NO_PIVOT{Super::N_MESSAGES};
 
   rclcpp::Clock::SharedPtr ros_clock_{nullptr};
 };

include/message_filters/time_synchronizer.hpp

@@ -40,10 +40,10 @@ namespace message_filters
 {
 
 /**
- * \brief Synchronizes up to 9 messages by their timestamps.
+ * \brief Synchronizes up to N messages by their timestamps.
  *
- * TimeSynchronizer synchronizes up to 9 incoming channels by the timestamps contained in their messages' headers.
- * TimeSynchronizer takes anywhere from 2 to 9 message types as template parameters, and passes them through to a
+ * TimeSynchronizer synchronizes up to N incoming channels by the timestamps contained in their messages' headers.
+ * TimeSynchronizer takes anywhere from 2 to N message types as template parameters, and passes them through to a
  * callback which takes a shared pointer of each.
  *
  * The required queue size parameter when constructing the TimeSynchronizer tells it how many sets of messages it should