deps: introduce cppgsl dependency for C++ core guidelines support

[knoepfel]

No description provided.

[coderabbitai]

Important

• 🔍 Trigger review

This repository does not receive automatic reviews because it has fewer than 10 stars.

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro Plus

Run ID: 6dee2203-a013-4ba5-954f-3dfc32804964

---

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.}

[greenc-FNAL]

Is there a particular minimum version of cppgsl required for the features you're currently using?

[knoepfel]

Is there a particular minimum version of cppgsl required for the features you're currently using?

@greenc-FNAL, I just pushed a change that requires version 4 of cppgsl or greater. PR Framework-R-D/phlex#839 assumes that the installed headers accord with a pattern that was introduced in version 4 (e.g.):

- #include <gsl/gsl_pointers>  // Before v4
+ #include <gsl/pointers>      // v4 and later