Write-up of opt-in deprecation warnings?

[svix-jplatte]

Hi, I just went through #3822 and other related GitHub / reddit threads to find a summary of the opt-in deprecation scheme that clap ended up with. Is my memory serving me wrong that such a write-up exists?

[epage]

Are you looking for justification for it, an explanation of the mechanics / pattern, or user facing "how to opt-in"?

[svix-jplatte]

Mostly an explanation of the pattern (I think there's not much to it, simple cfg-gated deprecation attributes?), probably with the motivation as an introduction. I thought I saw something like that before 😅

Context: wanted to link to it as prior art when mentioning the pattern for another project.

[epage]

#3830 is the main place I can think of which is linked to in the above. That included updates to our compatibility documentation and shows how we did this. One of the key things that requires extra work is when proc-macros need to call deprecated functionality.

[svix-jplatte]

Okay, so I guess I was imagining that there was a separate document / article about this pattern. Thanks 😄