Consider adding a macro for semantic cross references

[JohelEGP]

#4936 shows that when wording is refactored, it is necessary to manually keep in sync cross references, and that unfortunate references are left semantically dangling. For that particular case, #4832 was going to copy some dangling references. #4866 also fixed references to that subclause within [basic].

It seems like there is benefit to be found in a macro for doing semantic cross references. This means that they refer not to a fixed subclause label, but something closer to what is semantically cross referenced. The obvious candidate for this are indexed entities.

I am thinking of something along the lines of

\reference{matter involving an \grammarterm{id-expression}}{\grammarterm{id-expression}}

Is it possible to do that with LaTeX?

[jensmaurer]

Is it possible to do that with LaTeX?

Conceptually, what we need is a way to add \refs (or \irefs) to a named list of things in a first LaTeX pass, and then we expand a macro to that list in a later pass (not unlike what \ref does in the first place). We would then use a special marker when we use (e.g.) "unevaluated operand" in a way that complements the definition, and that special marker would add to the named list.

I don't think we should tie this to indexed things too tightly; we'd like to keep the option to index mentions of a term that we don't want to cross-reference like that.

@godbyk , any pointers would be much appreciated.

[jensmaurer]

I've misunderstood the original desire, I believe. It seems just \label and \ref will do what we want.

[jensmaurer]

Documented on the styles wiki:

For some defined terms (e.g. "odr-use"), we customarily add a cross-reference after a use of the term. In order to make that cross-reference stable against section moves of the definition of the term, create a \label{term.this.name} at the start of the paragraph defining the term, and use \ref or \iref referencing term.this.name`.