A join messaging block is a single-target, multi-source, ordered propagator_block which combines together messages of type _Type from each of its sources.
The payload type of the messages joined and propagated by the block.
The kind of join block this is, either greedy or non_greedy
Accepts a message that was offered by this join messaging block, transferring ownership to the caller.
Consumes a message previously offered by the join messaging block and reserved by the target, transferring ownership to the caller.
A callback that notifies that a new target has been linked to this join messaging block.
Asynchronously passes a message from an ISource block to this join messaging block. It is invoked by the propagate method, when called by a source block.
Constructs an output message containing an input message from each source when they have all propagated a message. Sends this output message out to each of its targets.
Releases a previous message reservation. (Overrides source_block::release_message.)
Reserves a message previously offered by this join messaging block. (Overrides source_block::reserve_message.)
Resumes propagation after a reservation has been released. (Overrides source_block::resume_propagation.)