Agner - Erlang style actor framework using C++20 coroutines.

Features

• Erlang process based actor framework
• OTP-style GenServer and Supervisor primitives
• FoundationDB style deterministic testing
• Optional Boost.Asio-backed scheduler and await bridges

Boost.Asio support

• Enable with CMake: cmake --preset default -DAGNER_ENABLE_BOOST_ASIO=ON.
• When enabled, <agner/agner.hpp> exposes agner::AsioScheduler; otherwise the aggregate header does not include the optional Boost-dependent header.
• AsioScheduler runs actors on a boost::asio::io_context and provides explicit await bridges via scheduler.await(...) or asio_await(scheduler, ...).
• Supported await inputs are Boost.Thread boost::future and boost::shared_future, std::future values such as those returned by Boost.Asio use_future, and boost::asio::awaitable.

Formal model

• spec/core_actor_system.tla models the actor core with an abstract nondeterministic scheduler, selective receive, and try_receive() timeouts.
• spec/core_actor_system.cfg explores the bounded core model. Focused configs under spec/ mirror mailbox ordering, receive suspension, timeout races, and missing-actor send semantics from the current test suite.
• Run TLC with tlc -cleanup -config spec/core_actor_system.cfg spec/core_actor_system.tla, or swap in one of the scenario configs for a narrower check.
• Link and monitor propagation are intentionally deferred so the first model can stay small enough for bug-finding runs.