iox-#2066 Switch to C++17

[elBoberido]

Pre-Review Checklist for the PR Author

1. Add a second reviewer for complex new features or larger refactorings
2. Code follows the coding style of CONTRIBUTING.md
3. Tests follow the best practice for testing
4. Changelog updated in the unreleased section including API breaking changes
5. Branch follows the naming format (iox-123-this-is-a-branch)
6. Commits messages are according to this guideline
   • Commit messages have the issue ID (iox-#123 commit text)
   • Commit author matches Eclipse Contributor Agreement (and ECA is signed)
7. Update the PR title
   • Follow the same conventions as for commit messages
   • Link to the relevant issue
8. Relevant issues are linked
9. Add sensible notes for the reviewer
10. All checks have passed (except task-list-completed)
11. All touched (C/C++) source code files from iceoryx_hoofs are added to ./clang-tidy-diff-scans.txt
12. Assign PR to reviewer

Notes for Reviewer

This PR moves the last two platforms, Linux and QNX, to the C++17 language standard. This means that we can start using C++17 features.

Checklist for the PR Reviewer

• Commits are properly organized and messages are according to the guideline
• Code according to our coding style and naming conventions
• Unit tests have been written for new behavior
• Public API changes are documented via doxygen
• Copyright owner are updated in the changed files
• All touched (C/C++) source code files from iceoryx_hoofs have been added to ./clang-tidy-diff-scans.txt
• PR title describes the changes

Post-review Checklist for the PR Author

1. All open points are addressed and tracked via issues

References

• Relates to Switch to C++17 on all platforms #2066

[codecov]

Codecov Report

Merging #2096 (16999d4) into master (4144844) will increase coverage by 0.11%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2096      +/-   ##
==========================================
+ Coverage   80.17%   80.29%   +0.11%     
==========================================
  Files         418      417       -1     
  Lines       16124    16110      -14     
  Branches     2250     2250              
==========================================
+ Hits        12928    12935       +7     
+ Misses       2398     2380      -18     
+ Partials      798      795       -3     

Flag	Coverage Δ
unittests	80.08% <ø> (+0.11%)	⬆️
unittests_timing	15.30% <ø> (+0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

see 7 files with indirect coverage changes

[elBoberido]

@FerdinandSpitzschnueffler @mossmaurice @dkroenke @MatthiasKillat @elfenpiff @budrus feel free to add yourself as reviewer

[mossmaurice]

Finally! 🥳

The PR looks good to me, with C++23 being released in a couple of weeks and many ISO 262626-certified compilers supporting C++17 I think we're ready to go for the v3.0 C release. This together with the iceoryx_hoofs restructuring will become the main two features of the next release.

The date for moving to C++20 would then be roughly the end of 2026 😁 I can't wait for modules and concepts.

[elBoberido]

@mossmaurice I hope the compiler vendors manage to get their act together and fully implement modules by then 😅