From<[T; M]> for CircularBuffer<N> where N < M should panic

[brett-lempereur]

I ran into this while setting up a unit test that I expected to panic. It's fairly simple to reproduce:

let buffer: CircularBuffer<2; u8> = [0x01, 0x02, 0x03].into();

The issue seems to be here https://github.com/andreacorbellini/rust-circular-buffer/blob/master/src/lib.rs#L1686. I guess this is a design choice, but I don't think I'd ever want to silently discard array elements while constructing a circular buffer.

It's a small (breaking) change, and I'm happy to open the MR for it. Thanks for the awesome library!

[andreacorbellini]

HI Brett, thanks for reporting this. What I think we can do is to have a From<[T; N]> for CircularBuffer<N> implementation, i.e. allow only conversion from an array of the same size of the buffer. This would result in build-time failures rather than runtime panics. I would avoid introducing fallible behavior in a From implementation: that's what TryFrom is for. This could be introduced in a 0.2 release to avoid breaking existing code. However, I would like to see more data points to be convinced that this is a desiderabile feature. I see pros and cons on both sides.

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On Fri, Jan 5, 2024, 05:27 Brett Lempereur ***@***.***> wrote: I ran into this while setting up a unit test that I expected to panic. It's fairly simple to reproduce: let buffer: CircularBuffer<2; u8> = [0x01, 0x02, 0x03].into(); The issue seems to be here https://github.com/andreacorbellini/rust-circular-buffer/blob/master/src/lib.rs#L1686. I guess this is a design choice, but I don't think I'd ever want to silently discard array elements while constructing a circular buffer. It's a small (breaking) change, and I'm happy to open the MR for it. Thanks for the awesome library! — Reply to this email directly, view it on GitHub <#9>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AACOKLTWKZJG6S37RUSY2N3YM4UGZAVCNFSM6AAAAABBNTC3NWVHI2DSMVQWIX3LMV43ASLTON2WKOZSGA3DMNBSGA2TOMA> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>