Add special case for initial on_entry events that have no associated action. This ensures that composite states have in turn their on_entry actions executed.

See subsequent_anonymous_transitions_composite_without_action (now passes) and subsequent_anonymous_transitions_composite_with_action (always passed).

Author: Rijom

include/boost/sml.hpp

@@ -1424,10 +1424,24 @@ struct sm_impl : aux::conditional_t<aux::is_empty<typename TSM::sm>::value, aux:
   }
   template <class TEvent, class TDeps, class TSubs, class... Ts,
             __BOOST_SML_REQUIRES(!aux::is_base_of<get_generic_t<TEvent>, events_ids_t>::value &&
-                                 !aux::is_base_of<get_mapped_t<TEvent>, events_ids_t>::value)>
-  bool process_internal_events(const TEvent &, TDeps &, TSubs &, Ts &&...) {
+                                 !aux::is_base_of<get_mapped_t<TEvent>, events_ids_t>::value &&
+                                 !aux::is_same<get_event_t<TEvent>, initial>::value)>
+  bool process_internal_events(const TEvent&, TDeps &, TSubs &, Ts &&...) {
     return false;
   }
+  template <class TEvent, class TDeps, class TSubs, class... Ts,
+            __BOOST_SML_REQUIRES(!aux::is_base_of<get_generic_t<TEvent>, events_ids_t>::value &&
+                                 !aux::is_base_of<get_mapped_t<TEvent>, events_ids_t>::value &&
+                                 aux::is_same<get_event_t<TEvent>, initial>::value)>
+  bool process_internal_events(const TEvent &event, TDeps &deps, TSubs &subs) {
+    policies::log_process_event<sm_t>(aux::type<logger_t>{}, deps, event);
+#if BOOST_SML_DISABLE_EXCEPTIONS
+    return process_event_impl<get_event_mapping_t<get_generic_t<TEvent>, mappings>>(event, deps, subs, states_t{},
+                                                                                    aux::make_index_sequence<regions>{});
+#else
+    return process_event_except_imp<get_event_mapping_t<get_generic_t<TEvent>, mappings>>(event, deps, subs, has_exceptions{});
+#endif
+  }
   template <class TEvent, class TDeps, class TSubs,
             __BOOST_SML_REQUIRES(aux::is_base_of<get_generic_t<TEvent>, events_ids_t>::value &&
                                  !aux::is_base_of<get_mapped_t<TEvent>, events_ids_t>::value)>

include/boost/sml/back/state_machine.hpp

@@ -114,11 +114,29 @@ struct sm_impl : aux::conditional_t<aux::is_empty<typename TSM::sm>::value, aux:
 
   template <class TEvent, class TDeps, class TSubs, class... Ts,
             __BOOST_SML_REQUIRES(!aux::is_base_of<get_generic_t<TEvent>, events_ids_t>::value &&
-                                 !aux::is_base_of<get_mapped_t<TEvent>, events_ids_t>::value)>
-  bool process_internal_events(const TEvent &, TDeps &, TSubs &, Ts &&...) {
+                                 !aux::is_base_of<get_mapped_t<TEvent>, events_ids_t>::value &&
+                                 !aux::is_same<get_event_t<TEvent>, initial>::value)>
+  bool process_internal_events(const TEvent&, TDeps &, TSubs &, Ts &&...) {
     return false;
   }
 
+  // This version is used by initial events that are not associated with any actions.
+  // Without this, composite classes will their initial events not have executed.
+  template <class TEvent, class TDeps, class TSubs, class... Ts,
+            __BOOST_SML_REQUIRES(!aux::is_base_of<get_generic_t<TEvent>, events_ids_t>::value &&
+                                 !aux::is_base_of<get_mapped_t<TEvent>, events_ids_t>::value &&
+                                 aux::is_same<get_event_t<TEvent>, initial>::value)>
+  bool process_internal_events(const TEvent &event, TDeps &deps, TSubs &subs) {
+    policies::log_process_event<sm_t>(aux::type<logger_t>{}, deps, event);
+#if BOOST_SML_DISABLE_EXCEPTIONS  // __pph__
+    return process_event_impl<get_event_mapping_t<get_generic_t<TEvent>, mappings>>(event, deps, subs, states_t{},
+                                                                                    aux::make_index_sequence<regions>{});
+#else   // __pph__
+    return process_event_except_imp<get_event_mapping_t<get_generic_t<TEvent>, mappings>>(event, deps, subs, has_exceptions{});
+#endif  // __pph__
+  }
+
+
   template <class TEvent, class TDeps, class TSubs,
             __BOOST_SML_REQUIRES(aux::is_base_of<get_generic_t<TEvent>, events_ids_t>::value &&
                                  !aux::is_base_of<get_mapped_t<TEvent>, events_ids_t>::value)>

test/ft/transitions.cpp

@@ -171,13 +171,13 @@ test subsequent_anonymous_transitions_composite_with_action = []{
   V calls{};
   //
   //        sub_sm
-  //        +--------------------------------+
-  //        |                                |
-  //        |       +---+       +---+ evExit |
-  //   *+--->  *+---> A +-------> B +----> X +----> X
-  //        |       +---+       +---+        |
-  //        |                                |
-  //        +--------------------------------+
+  //        +----------------------------------+
+  //        |                                  |
+  //        |       +----+       +----+ evExit |
+  //   *+--->  *+---> s1 +-------> s2 +----> X +----> X
+  //        |       +----+       +----+        |
+  //        |                                  |
+  //        +----------------------------------+
   //
 
   struct sub_sm {
@@ -219,13 +219,13 @@ test subsequent_anonymous_transitions_composite_without_action = []{
 
   //
   //        sub_sm
-  //        +--------------------------------+
-  //        |                                |
-  //        |       +---+       +---+ evExit |
-  //   *+--->  *+---> A +-------> B +----> X +----> X
-  //        |       +---+       +---+        |
-  //        |                                |
-  //        +--------------------------------+
+  //        +----------------------------------+
+  //        |                                  |
+  //        |       +----+       +----+ evExit |
+  //   *+--->  *+---> s1 +-------> s2 +----> X +----> X
+  //        |       +----+       +----+        |
+  //        |                                  |
+  //        +----------------------------------+
   //
 
   struct sub_sm {