Trying to understand the basics of Kotlin Multipla...

# multiplatform

[Kelvin Chung]

Trying to understand the basics of Kotlin Multiplatform here. One question I have is why value classes can be used as the actual to meet an expect declaration - for example:

expect class MyClass(value: Int) // common

@JvmInline
actual value class MyClass actual constructor(val value: Int) // jvm

Any high-level insight as to why that would be is appreciated.

[loke]

Not sure what kind of answer you're looking for?

[Kelvin Chung]

I get a compiler error saying that the second statement is not compatible with the first, saying that value makes it incompatible.

[loke]

Use expect value class ...

[Kelvin Chung]

What if the class on other platforms is not a value class?

[loke]

The semantics between value classes and regular classes is different.

[loke]

Just define it like so: expect value class Foo(val instance: Any) and then the value class can just be a wrapper around the real one.

[loke]

I actually did exactly that in my multiplatform bigint library.

[Kelvin Chung]

So it's not possible to have an expect where the actual is a value class on one platform and not a value class on another?

[loke]

That should not be possible, no.

[loke]

https://codeberg.org/loke/array/src/branch/master/mpbignum/src/commonMain/kotlin/com/dhsdevelopments/mpbignum/bigint.kt#L9