Use Boost PFR in node_catalog

[knoepfel]

Using Boost's PFR library, it's possible to retrieve a particular field from a struct based on the provided type.

[wddgit]

One question (not a suggestion one way or the other). Do you intend to remove the aliases like declared_predicates everywhere eventually?

Otherwise this looks good. It does bring in a dependence on boost PFR. I tried copilot on the PR and it helped me understand the PR quicker. It was able to explain what PFR was as I had never heard of it before.

[knoepfel]

Thanks for the review, @wddgit.

Do you intend to remove the aliases like declared_predicates everywhere eventually?

Yes, I'd like to remove those aliases eventually. I have some commits that I'm trying to package as small PRs before submitting the larger registration-API PR. This is one of those commits. I hope the aliases will eventually go away.

It does bring in a dependence on boost PFR. I tried copilot on the PR and it helped me understand the PR quicker. It was able to explain what PFR was as I had never heard of it before.

I stumbled on PFR by accident—I was looking for something else in Boost and clicked on the PFR library link to learn more. Eventually, I would like to get rid of the use of PFR, but that requires some refactoring that I'm not quite ready to do yet.