Fix issue 23400 - Can't format enum value whose base type has non-con…

[pbackus]

…st opEquals

---

Regression introduced by #8249.

[pbackus]

Failure is unrelated. For some reason, CirrusCI is unable to download DMD on FreeBSD 11.

[nordlow]

I'm not convinced we should allow non-const non-pure non-scope toString(). What do you think, @RazvanN7?

[pbackus]

@nordlow This bug has nothing to do with toString; it is about opEquals.

[pbackus]

Also, given that Obect.toString is non-const, non-pure, and non-scope, I think it's unlikely we'll be able to drop such support any time soon.

[pbackus]

Re: template bloat, it would be possible to reduce it in the common case by adding an overload specifically for enums with primitive base types (integers, characters, pointers) which takes its argument as const, since == on primitive types works the same regardless of qualifier.

[dlang-bot]

Thanks for your pull request and interest in making D better, @pbackus! We are looking forward to reviewing it, and you should be hearing from a maintainer soon.
Please verify that your PR follows this checklist:

• My PR is fully covered with tests (you can see the coverage diff by visiting the details link of the codecov check)
• My PR is as minimal as possible (smaller, focused PRs are easier to review than big ones)
• I have provided a detailed rationale explaining my changes
• New or modified functions have Ddoc comments (with Params: and Returns:)

Please see CONTRIBUTING.md for more information.

---

If you have addressed all reviews or aren't sure how to proceed, don't hesitate to ping us with a simple comment.

Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	23400	regression	[REG 2.099] Can't format enum value whose base type has non-const opEquals

Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "stable + phobos#8591"

[pbackus]

Rebased to pick up #8602

[thewilsonator]

stable?

[pbackus]

I guess it should be stable now, since we missed the master -> stable merge. Will rebase.