assert-order

A Rust crate for asserting the definition order of enum Variants.

Motivation

For serialization formats that aren't self-describing, the typical way for discriminating enum variants is to use an integer discriminant. Unfortunately, this means that reordering variants will cause deserialization of previously serialized data to fail (potentially silently).

In general, you can just document strict ordering and ensure that changes aren't made to the variant ordering. However, it is more comforting to have this documented requirement as an assertion in a test.

License

Licensed under the MIT license.