clang-tidy: resolve readability-use-concise-preprocessor-directives

[knoepfel]

Resolve readability-use-concise-preprocessor-directives clang-tidy warnings.

• Code quality: Resolved readability-use-concise-preprocessor-directives warnings in phlex/model/index_generator.hpp by simplifying feature-detection preprocessor directives.
• Documentation: Updated the clang-tidy fixes report with PR #772 and additional outstanding check entries, including bug-prone, modernize, security, and readability checks.

[coderabbitai]

📝 Walkthrough

Walkthrough

The PR adds clang-tidy checklist entries and updates index_generator.hpp to use revised compile-time checks for standard generator support.

Changes

Clang-tidy checklist updates

Layer / File(s)	Summary
Expanded clang-tidy checklist docs/dev/clang-tidy-fixes-2026-04.md	Adds unchecked entries for bugprone, security, modernize, and readability checks, including occurrence counts and the preserved readability PR reference.

Generator feature detection

Layer / File(s)	Summary
Standard generator compile-time guards phlex/model/index_generator.hpp	Updates __has_include probing and uses __cpp_lib_generator guards to select between the fallback implementation and std::generator.

Estimated code review effort: 2 (Simple) | ~10 minutes

Possibly related PRs

• Framework-R-D/phlex#757: Updates the same clang-tidy checklist with a readability check and PR reference.

Suggested reviewers: greenc-fnal

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly matches the PR’s main goal: fixing the clang-tidy readability-use-concise-preprocessor-directives warning.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

@@            Coverage Diff             @@
##             main     #772      +/-   ##
==========================================
+ Coverage   83.82%   83.93%   +0.11%     
==========================================
  Files         172      172              
  Lines        7210     7210              
  Branches      848      848              
==========================================
+ Hits         6044     6052       +8     
+ Misses        884      879       -5     
+ Partials      282      279       -3     

Flag	Coverage Δ
scripts	80.09% <ø> (ø)
unittests	85.86% <ø> (+0.16%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.
see 3 files with indirect coverage changes

---

Continue to review full report in Codecov by Harness.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 0be155e...6678066. Read the comment docs.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.