Warn on redundant update

[ndmitchell]

What it does

If your update changes no fields, e.g. MyRecord {..value} then the update is providing very little value, and value directly would be better.

Lint Name

redundant_update

Category

style

Advantage

• Simpler.

Drawbacks

No response

Example

MyRecord { ..value}

Could be written as:

value

[samueltardieu]

Are they really equivalent? MyRecord { ..value } moves value unless it implements Copy, so wouldn't MyRecord { ..value } be equivalent to value, and not value.clone()?

[ndmitchell]

@samueltardieu great point - thanks - that makes it an even better hint. I've edited the initial description to incorporate your observation.

[samueltardieu]

@rustbot claim