Hi all! Question that has probably been answered before, but I couldn’t find/understand those answers: Why do we need to annotate “value classes” with @JvmInline? Ie. why is it not implied that a “value class” should be inlined? And what is a “value class” without @JvmInline?

I guess my answer there can shed some light: https://stackoverflow.com/questions/68908343/how-are-kotlin-value-classes-different-from-inline-classes/68908472#68908472

Thank you, I understand now. Wish they would have kept inline classes and have that imply inlining. Those annotations are unsexy. But oh well..

The point is that these annotations will go away when there is a "better" implementation (Valhalla) instead of (or on top of) inlining. It's "ugly" right now so it can be beautiful in the long run 🙂

But I guess inlining doesn’t really make a noticeable performance difference, in day to day business logic code, so I’ll probably just skip those annotations, unless i really need it

You can't skip the annotations if you use

value class

at the moment, you have to use them because it's currently the only way `value class`es are supported on JVM (this is to ensure that new implementations without

@JvmInline

will be backwards-compatible)

Oh, I see

but if you don't care much about the inlining, you can always use a

data class

to create a typesafe wrapper.