I'm trying to write some code using `termios` in ...

# kotlin-native

[David Herman]

I'm trying to write some code using termios in K/N. termios is a struct which has a bitflag field called c_lflag ; its type is platform.posix.tcflag_t which appears to be an int on mac and a uint on linux.

I'm trying to do some bit logic like this: newTermios.c_lflag.and((_ECHO_.or(_ICANON_.or(_IEXTEN_))).inv()) (equivalent to c_lflag & ~(ECHO | ICNON | IEXTEN) in C).

In order to support both targets, I thought ECHO.or(...) as tcflag_t would work, but I'm getting a warning that the cast will never succeed.

What's the right solution here?

[David Herman]

(I'm pretty sure I could use expect / actual for this case, but that seems like overkill)

[David Herman]

It seems to me like I need to call .toUInt() on Linux and not on Mac

[ephemient]

use .convert()

[David Herman]

Ah, let me try. Thanks!

[David Herman]

Looks good so far, thank you, and sorry for the beginner question. (I was originally searching for a function like cast)

[ephemient]

no worries. there's clearly room for improvement in the docs https://kotlinlang.org/api/latest/jvm/stdlib/kotlinx.cinterop/convert.html

[Landry Norris]

Kotlin doesn't do the modifying casts you see with primitives in other languages (same issue casting int to double). You need the conversion methods, like toDouble. Convert is similar, but it checks the plaform type to convert to.

[ephemient]

not to confuse things too much, but

(fun (x: Double) { println(x) } as (Number) -> Unit).invoke(1 as Int)

works 😛

[ephemient]

(that is a bug in Kotlin/JVM though)

[ephemient]

https://youtrack.jetbrains.com/issue/KT-48645/JVM-prevent-implicit-coercions-between-different-numeric-types