100 days with Rust: a series of brick walls

Re:100 days with Rust: a series of brick walls by steveklabnik on Friday March 23, 2018 @06:11PM (#16663037)

? calls a conversion function. It only won't work if the error you're trying to return won't convert to the error that's in the type signature. Even then, you have options, like .map_err.

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Re:100 days with Rust: a series of brick walls by arghwhat on Friday March 23, 2018 @07:36PM (#16663597)

We have gone a bit down a tangent here. My original complaint was about the friction of different error types compared to other languages (like, say, Go).

Having to implement a bunch of From traits (unless you need io::Error, because everything seemed to have conversions from/to that), or having to implement inline error conversion through map_err, is such friction. I might go as far as consider it the most cumbersome error system I have used. Clean idea, cumbersome implementation.

My comment about '?' not working with mismatched types was mostly just to say that it doesn't fix anything, it just adds a bit of convenient syntactic sugar.

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Re:100 days with Rust: a series of brick walls by xfer on Friday March 23, 2018 @09:22PM (#16664146)

There is zero friction if you use either error_chain/failure crate and you can still recover the precise underlying errors. The only thing is it allocates.

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Re:100 days with Rust: a series of brick walls by arghwhat on Saturday March 24, 2018 @07:34AM (#16666093)

I will look into those crates next time!

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Re:100 days with Rust: a series of brick walls by red75prime on Saturday March 24, 2018 @01:21AM (#16665022)

failure has no_std feature for the no-heap cases.

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