Builder is now using the FSM I wrote. Still not as clean as I like but big improvement.

fsm.hpp

@@ -1,5 +1,10 @@
 #pragma once
 
+#include <fmt/core.h>
+
+#define FSM_EV(S, F) case S: F(); break
+#define FSM_STATE(S, F, E) case S: fmt::println(">>> " #S ":" #F ":{}", int(E)); F(E); break
+
 template<typename S, typename E>
 class DeadSimpleFSM {
 protected:
@@ -11,6 +16,8 @@ public:
   void state(S next_state) {
     _state = next_state;
   }
-};
 
-#define FSM_T(S, F) case S: F(); break
+  bool in_state(S state) {
+    return _state == state;
+  }
+};