The type of the environment is more specific in the implementations.
Executes a task and returns a future.
Executes a task and returns a future. Forwards an exception if some task threw it.
Executes a result task, waits for it to finish, then returns its result.
Executes a result task, waits for it to finish, then returns its result. Forwards an exception if some task threw it.
Retrieves the parallelism level of the task execution environment.
A trait that declares task execution capabilities used by parallel collections.