Crate does not compile on stable Rust < 1.36

[jean-noelp]

Hello,

It seems that your librairie does not compile anymore since the 1.6.0, and also, all dependencies does not compile anymore too! (like test-junit)

error[E0506]: cannot assign to `self.state` because it is borrowed

   --> /usr/local/cargo/registry/src/github.com-1ecc6299db9ec823/typed-arena-1.6.0/src/lib.rs:461:33

    |

451 |                     ref mut inner_iter,

    |                     ------------------ borrow of `self.state` occurs here

...

461 |                                 self.state = IterMutState::ChunkListRest { index, inner_iter };

    |                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `self.state` occurs here


error[E0506]: cannot assign to `self.state` because it is borrowed

   --> /usr/local/cargo/registry/src/github.com-1ecc6299db9ec823/typed-arena-1.6.0/src/lib.rs:467:33

    |

451 |                     ref mut inner_iter,

    |                     ------------------ borrow of `self.state` occurs here

...

467 |                                 self.state = IterMutState::ChunkListCurrent { iter };

    |                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `self.state` occurs here

We are using the nightly-2019-03-06 rust version.

Do you confirm this error ?
Could you check your publication please ?
:/

[rodrimati1992]

Can confirm that I had the same error in the CI for one of my libraries,in a job that uses Rust 1.34 .

It would benefit this library to have a minimum required version in the README,and enforce it in CI if it doesn't bump it in minor versions.

[brendanzab]

Yes, I've ran into this issue too, building on my pinned version of Rust, which used to build fine on Rust 1.32:

• Remove spanned string type yeslogic/fathom#168
• https://travis-ci.com/yeslogic/ddl/jobs/235770008

[brendanzab]

The PR that introduced this regression seems to be #30. It'd be nice if this could be fixed, and a specific rust version be pinned in the .travis.yml!

[brendanzab]

After some time trying different versions, it seems like Rust 1.36.0 works!

[fitzgen]

This crate hasn't made any promises about maintaining compatibility with specific rust versions, just that it will always compile on the stable channel.

I think it is reasonable to add a stronger stability guarantee, but doing so requires the CI changes mentioned above and backporting the code to work with older rust versions. If someone is willing to do those things, I would be happy to review the PR and be willing to start making those stronger versioning guarantees from then on out.

[brendanzab]

I don't think it's necessary to make a promise on this, but I have found that just having a specific version in the .travis.yml makes me consider whether or not I want to break backwards compatibility on a library, especially if there is an easier work around. It's also nice documentation. :)

I might see if I can look at this today.

[brendanzab]

Posted a patch at #33! Hope this helps!

[jean-noelp]

Thank you, we'll check this patch!

[fitzgen]

Published 1.6.1

[brendanzab]

Thanks! Really appreciate your work on maintaining this! 👏