Discussion: the proper location of msg type files

[takasehideki]

We initially thought the location of files related to the msg type of mros2 should be as follows.

• This repository, which manages mros2 as a library, should contain only std_msgs at mros2_msgs/.
  • because it includes basic types that are used standardly in all applications.
  • and also, the size of the library may be better as small as possible.
  • https://github.com/mROS-base/mros2/tree/main/mros2_msgs
• Custom msg types, generated by mros2_header_generator, should be located in each target repository.
  • e.g. in mros2-mbed: https://github.com/mROS-base/mros2-mbed/tree/main/workspace/custom_msgs/geometry_msgs/msg
  • because these types are used in each individual app

However, there are some commonly used types, such as geometry_msgs and sensor_msgs. Actually, sensor_msgs is now located at this mros2 repository: https://github.com/mROS-base/mros2/tree/main/mros2_msgs/sensor_msgs/msg
So we need to discuss again which location is suitable to manage these types.

[takasehideki]

I'm starting to think that the most commonly used types should be included in mros2_msgs/ (in this repository). This is because the generation of custom msg types is a common feature of mros2, not platform-dependent, and this way will make the usability higher.
The expected issue is that if users individually generate their own msg type files at their own locations, link conflict (duplication of include file) may happen.