PartialEq for all write types?

[rsheeter]

It would be helpful for the compiler to be able to check if an instance of a write type changed using == but the types don't consistently implement partialeq. Maybe write-types should just always have Capability::Equality?

Context googlefonts/fontc#359 (comment)

[cmyr]

Yea, I think this makes sense. Do we also want to add Ord/Hash?

[cmyr]

if we add them all then I can delete some codegen code, and there isn't a ton of downside; maybe slightly slower compilation, but the compiled code should get stripped if it's unused

[cmyr]

I'm going to go ahead and try that, I think it'll save us future headaches.

[rsheeter]

I don't find it as obvious that Ord and Hash make sense for everything?

[cmyr]

They're necessary if we ever want to put any of these types in a set. Overall none of these traits are 'always necessary', but we don't have perfect foresight of when they will be necessary, and the alternative (some ability to add them as needed in codegen) is more complicated and more work overall.