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High-Performance Hierarchical Finite State Machine

Header-only heriarchical FSM framework in C++11, with fully statically-defined structure (no dynamic allocations), built with variadic templates.

Permissive MIT License
Written in widely-supported modern(ish) C++11
Header-only
Convenient, minimal boilerplate
Fully static, no dynamic allocations
Uses inline-friendly compile-time polymorphism, no virtual methods are used
Type-safe transitions: FSM.changeTo<TargetState>() with optional payloads
Flexible configuration using HFSM2_ENABLE_* macros
Scalable, supports robust state re-use via state injections
Hierarchical, with a selection of composite (sub-machine) and orthogonal regions
Gamedev-friendly, supports explicit State::update()
Also supports traditional event-based workflow with State::react()
Inspect anything: previous and current transitions, state activation status, and more!
Game AI-friendly with dynamic planning support
Utility theory support (max score and ranked weighted random)
Serializable, with activity and transition history support
Debug-assisted, includes automatic structure and activity visualization API with #define HFSM_ENABLE_STRUCTURE_REPORT
Built-in logging support