boost-ext/sml

C++14 State Machine library observed · 2026-10-17

github.com/boost-ext/sml · homepage · C++ · BSL-1.0 (other) observed · 2026-10-17

Health v2 · maintenance only

81/100

Activity 100
Release rhythm 47
Longevity 100

How is this computed?

round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10) — computed 2026-10-21. Adoption (stars, forks) is never an input.

gap_med: 212.0
age_days: 3972
days_rel: 141
days_push: 4
n_releases_24m: 3

Full methodology

Adoption not part of the score

1410 stars · 209 forks observed · 2026-10-17

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded

Boost::ext.SML is a C++14 one-header-only state machine library with no dependencies, providing a UML-compliant transition table DSL (src_state + event [guard] / action = dst_state). It is designed for fast compilation, small binaries, and scalable use in large projects as an alternative to Boost.MSM eUML.

Use cases

implement a finite state machine in C++
replace spaghetti conditional logic with a state machine
model protocol state transitions like TCP connection handling
define UML-compliant state machines with guards and actions
add a lightweight header-only FSM to an embedded or large-scale C++ project

When to choose

you need a fast-compiling, dependency-free C++ state machine library
you want a UML-compliant transition table DSL without macros
you want to pass dependencies to states/actions via constructor injection
you need O(1) event processing with low memory overhead

When to avoid

you need runtime-defined or dynamically reconfigurable state machines
you require Boost.MSM's full feature set or data stored in states
your project targets a language other than C++14 or later

Facets

library · maturity stable

state-management developer-tools developer-tools programming-languages cpp cross-platform state-machine header-only cpp14 metaprogramming uml fsm boost-ext algorithms

2 sources

readme: https://github.com/boost-ext/sml · fetched 2026-10-17 · be27f246a75b
homepage: https://boost-ext.github.io/sml/ · fetched 2026-08-29 · b374454c0a80

Member repositories

Repository	Role	Health v2
boost-ext/sml	main	81

For agents

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Data as of 2026-10-19T08:05:51.212177+00:00 · Report a problem