Expose SealedTrait.Subtype constructor fields

[jatcwang]

In some usecases, the typeclass instance of a subtype can be modified, so it is useful to allow library authors to recreate the Subtype.

This is the case for difflicious since you can be given a Differ[ComplexType] and be able to "tweak" the individual Differs that made up the Differ[ComplexType] instance. In the Scala 2 implementation, You can see me recreating Subtype after transforming the subtype's Differ

[adamw]

Wouldn't the public interface become confusing once we expose all of these members? Maybe just exposing index would be sufficient, as that's the only piece of information not available through other means?

[jatcwang]

You're right. Updated :)

[adamw]

Thanks :)