+2021-04-24 Simon Marchi <simon.marchi@polymtl.ca>
+
+ * observable.h (class observable) <struct observer>: New.
+ <detach, notify>: Update.
+ <m_observers>: Change type to vector of observers.
+
2021-04-23 Simon Marchi <simon.marchi@polymtl.ca>
* observable.h (observer_debug): Change to bool.