Attention: Answers.ros.org is deprecated as of August the 11th, 2023. Please visit robotics.stackexchange.com to ask a new question. This site will remain online in read-only mode during the transition and into the foreseeable future. Selected questions and answers have been migrated, and redirects have been put in place to direct users to the corresponding questions on Robotics Stack Exchange. Additional details are available here.

Is it possible to do *ros_msg?

asked 2012-09-12 10:43:17 -0500

Ammar
289 ●25 ●30 ●41

Hi Community, I am working on a project that involves me defining various ROS msgs most of which are nested with other msgs that I have defined. Anyhow my question is regarding passing these ROS msgs within functions. I create a Ptr to a message, fill in values in it and then push it on a list. Since I create a Ptr to a ros_msg, in order to push it to a list I use *ros_msg, similar to any C++ data structure. I was wondering if this is correct, since it compiles without any errors. Thanks Ammar

edit retag flag offensive close merge delete

add a comment

1 Answer

Sort by » oldest newest most voted

answered 2012-09-12 11:19:58 -0500

jdlangs
971 ●23 ●47 ●45

I think the better practice would just be to store the pointers themselves. Pushing *msg onto a list will create a (maybe unnecessary) copy of the entire message, whereas copying just the pointer object is cheap. It's also memory-safe because they are shared pointers and there is therefore no worry about the object being deleted or needing an "owner" to free the memory at the end.

Then to access any message data members, just use the standard c++ -> syntax (ptr->member) in place of (*ptr).member

edit flag offensive delete link

add a comment

Question Tools

1 follower

Stats

Asked: 2012-09-12 10:43:17 -0500

Seen: 207 times

Last updated: Sep 12 '12

Is it possible to do *ros_msg? edit

1 Answer

Question Tools

Stats

Related questions

Is it possible to do *ros_msg?