Feedback request: How to handle unsupported "self-describing-only" attributes

[jamesmunns]

Hey there,

There are a number of attributes that can be used in serde that seem to cause problems with non-self describing formats like postcard. Some issues include:

• [Bug] Postcard does not handle serde attribute skip_serializing_if properly jamesmunns/postcard#122
• #[serde(flatten)] causes serialization to fail jamesmunns/postcard#29

This is unfortunate, as in many cases (I don't have a comprehensive list of all affected attributes):

• The code will still compile
• Serialization will usually succeed (at least: return without Error)
• Deserialization will fail (return an Error), or will deserialize incorrectly (returns wrong data).

Is there any way you are aware of to do one of the following?

• Skip these attrs, or
• Make them a compile time error

Right now my only answer is "don't do that", and I should probably add a bigger warning about it, as it is a thing that people often hit, particularly when they are using the same data formats with different wire formats (e.g. a JSON-to-postcard adapter).