Data queues similar to the Pipe module in Jane Street's Async library. They are implemented with Queues, limited in size, and use Lwt primitives for concurrent access.

Unbounded is a variant of Bounded where there is no size limit. It is equivalent to using Bounded with compute_size = Fun.const 0 but some functions are specialised to this particular setup.

Maybe_bounded are pipes that may or may not be bounded. This is decided when createing the pipe and can be queried with the bounded function.