namespace react
{
	// Single-threaded sequential updating
	class ToposortEngine<sequential>;

	// Multi-threaded parallel updating
	class ToposortEngine<parallel>;

	// Queuing of input from multiple threads
	class ToposortEngine<sequential_queue>;
	class ToposortEngine<parallel_queue>;

	// Pipelining of input from multiple threads (experimental)
	class ToposortEngine<parallel_pipeline>;
}