[Clang-Tidy] Inefficient string concatenation

[SunBlack]

Just a ticket as notification, so I can link information to clang-tidy ticket:

Current issues I won't fix, because they are not this much important and imho decrease readability:

string concatenation results in allocation of unnecessary temporary strings; consider using 'operator+=' or 'string::append()' instead.

Affected lines:

https://github.com/PointCloudLibrary/pcl/blob/816391762918f3a026b1822fe42c74bb83129eb4/apps/src/face_detection/filesystem_face_detection.cpp#L231

https://github.com/PointCloudLibrary/pcl/blob/816391762918f3a026b1822fe42c74bb83129eb4/recognition/src/face_detection/face_detector_data_provider.cpp#L83

https://github.com/PointCloudLibrary/pcl/blob/816391762918f3a026b1822fe42c74bb83129eb4/recognition/src/face_detection/face_detector_data_provider.cpp#L91

[SergioRAgostinho]

Don't forget to mark them appropriately to suppress the linter message.

[SunBlack]

I just disable the check in general as I don't like the syntax of the faster version ;).

[stale[bot]]

Marking this as stale due to 30 days of inactivity. It will be closed in 7 days if no further activity occurs.

[SunBlack]

Just a general question: Is it really useful to mark every issue as stale now and close them in 7 days? I don't believe we will fix all issues within 30 days after last comment.

[kunaltyagi]

Closing within 7 days is just to give time for someone to respond (in a general case, this is not general). Stale-bot was out of action for a long time, hence we have a deluge of such issues, but I expect to either close or label issues correctly within 7 days (with some help). The aim is to keep issues such as proposal, bug, question, request active, while letting todo and the maintainer action needed stay un-stale.

Later on, once things have settled down, it would help us in reminding about old issues we've quite forgotten about.