Documented the #[repr(align(x))] attribute.

[bitshifter]

Updated reference for stabilization of the #[repr(align(x))] attribute. See tracking issue comments rust-lang/rust#33626 (comment) for discussion.

[Havvy]

I thought I removed most of the verbiage of the repr attribute from the attributes page. Whoops.

You'll instead want to add a section ```The align representation` to `type-layout.md`.

[bitshifter]

Ah OK, should I leave the text I added to attributes.md since it's already talking about the other repr attributes?

[Havvy]

It's better to just link to the full description of the representation attribute from the attributes.md page, so as to avoid duplicating information too much. I just forgot to clean up the attributes.md page when the type layout page landed.

[Havvy]

The prose is good, just the paragraph structure feels off.

Also, since Github doesn't let me put a comment on lines you're not touching, on line 109 of type layout, you need to add align to the list.

Also, Github doesn't notify me when there are new commits. Leave a comment or else I won't see it quickly.

[Havvy]

This should be called The `align` Representation.

[Havvy]

Github ate most of my previous review comments. ;.; So here's a redo at the review.

[Havvy]

You got rid of the The here.

[Havvy]

This section should also be included in the align representation section.

[Havvy]

The paragraph structure here should mirror the packed representation section. So which categories of types it can be applied to should be one paragraph, and what it does should be another.

[Havvy]

Remove the (x) from the name. Instead, describe how it takes the alignment as a parameter in the paragraph describing how it works.

[bitshifter]

Thanks @Havvy I think I've addressed your feedback. This stuff hasn't been stabilized quite yet so you might want to wait until that happens before accepting the PR I guess.

[Havvy]

Github shows that you did a force push, but I don't actually see any changes in the new commit. I even checked your branch and there's no difference there either.

[bitshifter]

Whoops, I did a git commit --amend but forgot to add first. Should be updated now.

[Havvy]

Waiting on stabilization in the compiler.

[Havvy]

I have not updated the reference Attribute syntax grammar documentation as the new syntax is only used by #[repr(align)] and I thought it might be pretty confusing to include a grammar which is only used by one kind of attribute for now. &mdash @bitshifter; rust-lang/rust #33626

Even if it's a change used by one attribute, it should still be in the attribute grammar. Do you want to add it? If not, I'll do so in a separate PR.

[bitshifter]

Sorry, I didn't see your comment about the grammar. I can look at adding it.

[bitshifter]

Updated the grammar, hopefully I got it right! It looks like my stabilization PR is almost in.

[Havvy]

@bitshifter There's a merge conflict. 😢

[bitshifter]

@Havvy the conflict was on a section on repr attributes that I removed as part of this review, had recently been updated by @yellow-apple. Thus I've removed the edit with the rest of the section, but perhaps @yellow-apple should check the type-layout.md section on #[repr(C)] Enums to make sure it contains the same information (it's worded differently but seems semantically similar to me).

[Havvy]

💟 Thanks!