sigslot

Offers both thread-safe (sigslot::signal) and non-thread-safe (sigslot::signal_st) variants, with unit-tested cross-thread and recursive emission safety, as highlighted in the implementation details.

Automatically disconnects slots when tracked objects like std::shared_ptr or QObject are destroyed, preventing dangling references through extensible ADL adapters, as shown in the examples.

Provides sigslot::scoped_connection for scope-bound disconnection and sigslot::connection for manual control, simplifying resource management in complex event flows.

Supports slot groups with assignable IDs to enforce predictable invocation order, useful for sequencing event handlers in ascending group order.