A small proposal, currently on Kotlin Multiplatfor...

# multiplatform

[fabianhjr]

A small proposal, currently on Kotlin Multiplatform if someone wants to define value classes one has to use @JvmInline annotation on jvm sourcesets and not use it on non-jvm sourcesets which creates an unnecessary platform sourceset split since the code could otherwise be platform agnostic.

Since it is an annotation to indicate to the JVM backend to use a specific opitimazation other targets (Kotlin/JS and Kotlin/Native) could just ignore it without throwing an error. (Treat it as a no-op on non-jvm backends)

Filed on YouTrack: https://youtrack.jetbrains.com/issue/KT-53404/Treat-JvmInline-annotations-as-no-op-on-non-jvm-backends-for-better-Multiplatform-experience

Example on playground: https://pl.kotl.in/R4XMcQfCJ

// ^ Try different backends
// v And commenting out or not
// @JvmInline
value class NonEmptyString(val value: String) {
    init {
        require(value.isNotEmpty())
    }
}

fun main() {
    println(NonEmptyString("Hello"))
    try {
        println(NonEmptyString(""))
    } catch(e: Throwable) {
        println("Woops!")
    }
}

Slack Conversation

[Michael Paus]

I just gave your example a try. After adding the proper import statement

import kotlin.jvm.JvmInline

your code compiles and runs just fine on iOS and on JS where it should not be runnable according to your statements.