Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Remove mention of contravariance possibly getting scrapped #177

Merged

Conversation

petertodd
Copy link
Contributor

Contravariance is part of stable Rust, and it's a natural outcome of how fn(T) interacts with lifetimes, so it's hard to imagine this ever going away.

tl;dr: LONG LIVE CONTRAVARIANCE!

Contravariance is part of stable Rust, and it's a natural outcome of how
`fn(T)` interacts with lifetimes, so it's hard to imagine this ever
going away.

tl;dr: LONG LIVE CONTRAVARIANCE!
@petertodd
Copy link
Contributor Author

I'll have to admit an ulterior motive here though: I actually have a project with a PhantomData<fn(&'a ())> in one of the types, because the API needs contravariance over 'a. So I'd really like it to not go away. :)

@Centril
Copy link
Contributor

Centril commented Dec 12, 2019

cc @matthewjasper @nikomatsakis

@matthewjasper matthewjasper merged commit 3e6e100 into rust-lang:master Dec 14, 2019
@matthewjasper
Copy link
Contributor

Thanks!

@petertodd petertodd deleted the 2019-12-long-live-contravariance branch December 19, 2019 14:58
@nikomatsakis
Copy link

I agree we will not be removing it

JohnTitor added a commit to JohnTitor/rust that referenced this pull request Jan 7, 2020
Update books

## nomicon

1 commits in 8be35b201f9cf0a4c3fcc96c83ac21671dcf3112..3e6e1001dc6e095dbd5c88005e80969f60e384e1
2019-12-01 13:02:12 -0500 to 2019-12-14 22:08:52 +0000
- Remove mention of contravariance possibly getting scrapped (rust-lang/nomicon#177)

## reference

4 commits in d8dfe1b..e115753
2019-12-14 21:04:58 +0100 to 2019-12-22 13:13:14 +0100
- Fix typo in macros-by-example.md (rust-lang/reference#733)
- Remove `extern` from exception list (rust-lang/reference#732)
- Added clearification that closures are refered to lambdas (rust-lang/reference#731)
- abi.md: clarify #[used] and linking (rust-lang/reference#712)

## book

2 commits in ef8bb568035ded8ddfa30a9309026638cc3c8136..5c5cfd2e94cd42632798d9bd3d1116133e128ac9
2019-11-28 11:00:04 -0600 to 2019-12-16 09:27:21 -0600
- document new --show-output option in ch 11-2 (Rust &gt;= 1.39) (rust-lang/book#2065)
- Fix sentence in ch07 (rust-lang/book#2183)

## rust-by-example

3 commits in b7ac1bc76b7d02a43c83b3a931d226f708aa1ff4..1d59403cb5269c190cc52a95584ecc280345495a
2019-12-02 11:38:43 -0300 to 2019-12-27 08:27:05 -0300
- Enable section-folding of table of content (rust-lang/rust-by-example#1290)
- Remove unnecessary lifetime annotation (rust-lang/rust-by-example#1300)
- eliminate the warnings (rust-lang/rust-by-example#1301)

## edition-guide

1 commits in 6601cab4666596494a569f94aa63b7b3230e9769..1a2390247ad6d08160e0dd74f40a01a9578659c2
2019-11-22 12:08:58 -0500 to 2019-12-29 10:40:55 -0800
- Updated install and uninstall instructions (rust-lang/edition-guide#194)

## embedded-book

1 commits in c26234930282210849256e4ecab925f0f2daf3be..9493b7d4dc97eda439bd8780f05ad7b234cd1cd7
2019-12-07 17:25:11 +0000 to 2019-12-27 20:05:00 +0000
- fixed typo in Interrupts.md  (rust-embedded/book#218)
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

Successfully merging this pull request may close these issues.

4 participants