Hey! Is it possible to create an `CPointer<BooleanVar>` without the use of the nativeHeap? I w...

# kotlin-native

[Sebastian Keller]

Hey! Is it possible to create an CPointer<BooleanVar> without the use of the nativeHeap? I would like to create one on the stack, but everything i've tried failed.
Currently im using this

val flag = nativeHeap.alloc<BooleanVar>(); flag.usePinned { it.get().ptr /* <- CPointer<BooleanVar> */}

[Sebastian Keller]

I need to call fun fileExistsAtPath(path: String, isDirectory: CPointer<BooleanVar?): Boolean (iOS) and want to know if path is a directory or not.

[jonnyzzz]

Try cValue<T>(){...} function to allocate a Var.
The memScope{..} block is a replacement for nativeHeap, it releases all allocations at the end of the block

[Sebastian Keller]

But that would still use the heap, right? Something like this is not possible?

[Sebastian Keller]

bool b = false; bool *ptr = &b; functionThatUsesBoolPtr(ptr);

[jonnyzzz]

I think we cannot extract a mutable pointer for a variable. I would implemented that as follows:

import kotlinx.cinterop.BooleanVar
import kotlinx.cinterop.CPointer
import kotlinx.cinterop.alloc
import kotlinx.cinterop.memScoped
import kotlinx.cinterop.ptr
import kotlinx.cinterop.value

fun x(b: CPointer<BooleanVar>?) = 42

val test = memScoped {
  x(alloc<BooleanVar> { value = false }.ptr)
}

where alloc is the function that is available inside the memScoped block. It allocates the boolean

[Sebastian Keller]

alright, thank you very much!