Learning that you can use unions in C for grouping things into namespaces

Re:Learning that you can use unions in C for grouping things... by gumby on Monday August 02, 2021 @06:15PM (#28043381)

This is awesome. I referenced cppreference, but that is not authoritative. Unfortunately, in the final draft, [class.pre] grammar makes the name mandatory even though the language you quote remains in the first textual paragraph following the grammar specification!

The part of enums you quoted was C-compatible enums; anonymous scoped enums are explicitly forbidden: "The optional enum-head-name shall not be omitted in the declaration of a scoped enumeration" (dcl.enum 2).

Sigh. I will send in a clarification at least on the class/struct/union side. Ideally the grammar would be fixed rather than that paragraph.

The draft I looked at is https://timsong-cpp.github.io/cppwp/n4868/ (2020-10-18, shortly after the standard was approved).

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Re:Learning that you can use unions in C for grouping things... by jcelerier on Tuesday August 03, 2021 @06:31AM (#28047570)

> Unfortunately, in the final draft, [class.pre] grammar makes the name mandatory even though the language you quote remains in the first textual paragraph following the grammar specification!

That's pretty strange, considering e.g. this paper for quite some time ago: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p022... which is written as if anonymous structs always were a thing.

I wonder if there isn't a deep confusion somewhere where "anonymous" and "unnamed" mean different things to different persons.

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