Is there a way to perform a not-null assertion (`!...

# multiplatform

[Edoardo Luppi]

Is there a way to perform a not-null assertion (!!) without having the compiler generate checks?
I have A LOT of them in some generated code unfortunately, and I don't want the performance penalty, especially in non-JVM platforms.

[kevin.cianfarini]

On JS there’s unsafeCast which does what you want. On native there’s reinterpret but that’s restricted to pointer types.

[CLOVIS]

Have you measured a performance penalty? Checking if a reference is null is one of the most basic computer operations

[Edoardo Luppi]

Not really, but it's a parser (and lexer) code, from which I'd like to get the best possible performance outcome.
I'll try to benchmark tho.

[Edoardo Luppi]

Tested the compiled result and the Kotlin compiler is actually smart enough to automatically get rid of redundant checks.

[Edoardo Luppi]

So the actual checks I end up with are minimal.

[zsmb]

There's a long discussion on this here https://discuss.kotlinlang.org/t/run-time-null-checks-and-performance/2086/20

Includes the compiler flags you can set to remove (some of?) these assertions.

[Edoardo Luppi]

Thanks @zsmb! Do you happen to know if those compiler arguments are applicable to non-JVM targets?
To me it looks like they're really just for the JVM.

[zsmb]

It does seem like they're JVM-specific, but I don't know the details of them very well, just remembered that they exist.

If you do see specific performance problems on non-JVM platforms, filing a YouTrack issue on the KT project is likely the best course of action.

[Edoardo Luppi]

Sounds good, no worries. I'll ask on the JavaScript channel.

[Edoardo Luppi]

Answer is there is nothing comparable in JS, for example. Will create an issue.