[jira] [Commented] (ARROW-10002) [Rust] Trait-specialization requires nightly

["Andy Grove (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/ARROW-10002?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17204858#comment-17204858 ] 

Andy Grove commented on ARROW-10002:
------------------------------------

It seems like everyone so far agrees with the direction. The next question is when do we do this and who wants to do this. Given that the 2.0.0 release is targetted for next week, should we move this to 3.0.0?

> [Rust] Trait-specialization requires nightly
> --------------------------------------------
>
>                 Key: ARROW-10002
>                 URL: https://issues.apache.org/jira/browse/ARROW-10002
>             Project: Apache Arrow
>          Issue Type: Sub-task
>          Components: Rust
>            Reporter: Kyle Strand
>            Priority: Major
>              Labels: pull-request-available
>             Fix For: 2.0.0
>
>          Time Spent: 1h 10m
>  Remaining Estimate: 0h
>
> Trait specialization is widely used in the Rust Arrow implementation. Uses can be identified by searching for instances of {{default fn}} in the codebase:
>  
> {code:java}
> $> rg -c 'default fn' ../arrow/rust/
>  ../arrow/rust/parquet/src/util/test_common/rand_gen.rs:1
>  ../arrow/rust/parquet/src/column/writer.rs:2
>  ../arrow/rust/parquet/src/encodings/encoding.rs:16
>  ../arrow/rust/parquet/src/arrow/record_reader.rs:1
>  ../arrow/rust/parquet/src/encodings/decoding.rs:13
>  ../arrow/rust/parquet/src/file/statistics.rs:1
>  ../arrow/rust/arrow/src/array/builder.rs:7
>  ../arrow/rust/arrow/src/array/array.rs:3
>  ../arrow/rust/arrow/src/array/equal.rs:3{code}
>  
> This feature requires Nightly Rust. Additionally, there is [no schedule for stabilization|https://github.com/rust-lang/rust/issues/31844#issue-135807289] , primarily due to an [unresolved soundness hole|http://aturon.github.io/blog/2017/07/08/lifetime-dispatch]. (Note: there has been further discussion and ideas for resolving the soundness issue, but to my knowledge no definitive action.)
> If we can remove specialization from the Rust codebase, we will not be blocked on the Rust team's stabilization of that feature in order to move to stable Rust.



--
This message was sent by Atlassian Jira
(v8.3.4#803005)