paritytech / paritytech/parity-scale-codec

A way to require enum variant index being specified

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#666 2 comments 0 reactions 0 assignees View on GitHub

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Dominant language
Rust
Stars
287
Forks
103
Avg merge
6d 13h
Merged PRs (30d)
1

Description

I think it would be valuable to make an enum variant index required in derived code.

The way to approach this might be to have a separate feature that would generate a compile-time warning when #[codec(index = something)] is missing.

This is important in blockchain environment where some data structures can evolve over time and refactoring can accidentally break things.

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Research direction

Start by locating the derived-code handling for #[codec(index = something)] and how feature-gated compile-time diagnostics are implemented. Determine how missing enum variant indexes should be detected and verify that the chosen feature emits a warning without affecting explicitly indexed variants; add or run the relevant derive tests if available.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
blockchain
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
30/100

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