Anonymous transition in a nested state are not being executed unless on_entry event is declared in transition table

[deoliveiravinicius]

Anonymous transitions in a nested state are not being executed unless on_entry event is declared in transition table.

The following test, which is a slightly modified version of this line 112, fails if we remove on_entry action in the sub_sm

test subsequent_anonymous_transitions_composite = [] {
  using V = std::string;
  V calls{};

  using namespace sml;

  struct sub_sub_sm {
    auto operator()() noexcept {
      // clang-format off
      return make_transition_table(
       *idle / [] (V& v) { v+="ss1|"; } = s1
       ,s1 / [] (V& v) { v+="ss2|"; } = s2
       ,s2 / [] (V& v) { v+="ss3|"; } = X
      );
      // clang-format on
    }
  };
  struct sub_sm {
    auto operator()() noexcept {
      // clang-format off
      return make_transition_table(
       *idle / [] (V& v) { v+="s1|"; } = s1
       ,s1 / [] (V& v) { v+="s2|"; } = s2
       ,s2 / [] (V& v) { v+="s3|"; } = state<sub_sub_sm>
       ,state<sub_sub_sm> / [] (V& v) { v+="s4|"; } = X
      // ,state<sub_sub_sm> + sml::on_entry<_>/[]{}   // REMOVING THIS LINE CAUSES THE ANONYMOUS TRANSITIONS IN THE NESTED STATE MACHINE TO NOT EXECUTE
      );
      // clang-format on
    }
  };

  struct composite_sm {
    auto operator()() noexcept {
      // clang-format off
      return make_transition_table(
       *idle / [] (V& v) { v+="11|"; } = s1
       ,s1 / [] (V& v) { v+="12|"; } = state<sub_sm>
       ,state<sub_sm> / [] (V& v) { v+="13|"; } = s2
       ,s2 / [] (V& v) { v+="14|"; } = s3
      );
      // clang-format on
    }
  };
  sml::sm<composite_sm> sm{calls};
  expect(sm.is<decltype(state<sub_sm>)>(X));
  expect(sm.is(s3));
    std::string expected("11|12|s1|s2|s3|ss1|ss2|ss3|s4|13|14|");
  expect(calls == expected);  
  std::cout << "call order: " << calls << std::endl;
};

Test output:

result:
call order: 11|12|

expected:
call order: 11|12|s1|s2|s3|ss1|ss2|ss3|s4|13|14|

Specifications

• Version: 1.1.11
• Platform: Ubuntu 22.04