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

No error for private type in public async fn #64692

Open
CryZe opened this issue Sep 22, 2019 · 4 comments
Open

No error for private type in public async fn #64692

CryZe opened this issue Sep 22, 2019 · 4 comments
Labels
A-async-await Area: Async & Await A-visibility Area: Visibility / privacy. AsyncAwait-Triaged Async-await issues that have been triaged during a working group meeting. C-bug Category: This is a bug. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue.

Comments

@CryZe
Copy link
Contributor

CryZe commented Sep 22, 2019

Playground

mod foo {
    struct Bar;
    
    pub async fn bar() -> Bar {
        Bar
    }
}

This compiles just fine, despite the async fn returning a private type. There is a warning, but that's about it.

warning: private type `foo::Bar` in public interface (error E0446)
 --> src/lib.rs:4:5
  |
4 | /     pub async fn bar() -> Bar {
5 | |         Bar
6 | |     }
  | |_____^
  |
  = note: `#[warn(private_in_public)]` on by default
  = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
  = note: for more information, see issue #34537 <https://github.com/rust-lang/rust/issues/34537>

I don't think the warning was intended for async fn. This seems like it slipped through for async fn.

@jonas-schievink jonas-schievink added A-async-await Area: Async & Await A-visibility Area: Visibility / privacy. AsyncAwait-Unclear C-bug Category: This is a bug. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Sep 22, 2019
@cramertj
Copy link
Member

We should look into turning the future-compat warning into a hard error for uses inside async fn, but given that we do already issue a future-compat warning I don't think this is a blocking issue.

@cramertj cramertj added AsyncAwait-Triaged Async-await issues that have been triaged during a working group meeting. and removed AsyncAwait-Unclear labels Sep 24, 2019
@Centril
Copy link
Contributor

Centril commented Oct 8, 2019

cc @petrochenkov re. @cramertj's idea and the feasibility of doing this specially for async fn.

@nikomatsakis
Copy link
Contributor

We discussed briefly in the meeting and we were saying that maybe this future-compat warning should just go away entirely, in light of rust-lang/rfcs#2145

@petrochenkov
Copy link
Contributor

So, the plan is not to make this a hard error, but rather removing it and replacing with a different similarly (but more intuitively) behaving lint.

In the meantime, private-in-public being a warning for async functions is ok, async functions returning private types will be unusable outside of those types' modules anyway.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
A-async-await Area: Async & Await A-visibility Area: Visibility / privacy. AsyncAwait-Triaged Async-await issues that have been triaged during a working group meeting. C-bug Category: This is a bug. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue.
Projects
None yet
Development

No branches or pull requests

6 participants