Function interleaved_pairs 

pub async fn interleaved_pairs<'c, LEFT, RIGHT, OUTPUT, CONTEXT, OUTPORT, F, E>(
    left: BoxStream<VPacket<LEFT>>,
    right: BoxStream<VPacket<RIGHT>>,
    outputs: &mut OUTPORT,
    ctx: &'c CONTEXT,
    func: &'static F,
) -> Result<(), E>
where
    CONTEXT: Clone + ConditionallySendSync,
    F: Fn(LEFT, RIGHT, CONTEXT) -> BoxFuture<Result<OUTPUT, E>> + ConditionallySendSync,
    OUTPORT: SingleOutput + ConditionallySendSync,
    LEFT: DeserializeOwned + Clone + ConditionallySendSync,
    RIGHT: DeserializeOwned + Clone + ConditionallySendSync,
    OUTPUT: Serialize + ConditionallySendSync,
    E: Display + ConditionallySendSync,

Operation helper for common binary operations that have one output.