I was going through old slides and came across some lines
auto msg = pub->create_shared_message() in the slide deck from the state of ROS2 in 2014 .
While that’s clearly been long going since at least beta3, I was curious to learn why that functionality was removed. That seems actually very useful and from some discussions we’ve had on the real-time front regarding getting loaned messages from the middleware to take some reserved memory, this seems like a natural way to do it from a user-level API. Recreating it, or some derivative, could get folks in the work flow that will be necessary later on when that is implemented.
I see some comments on loaned messages that didn’t quite make it for Eloquent , but I can’t really find any reference other than this slide deck to the
create_shared_message() incarnation of the API in
rclc (no tickets or PRs reference it). Clearly  and  are not directly correlated, just noting the value that a method like this may have for wrapping that concept to a user.