just refreshed my memory on stuff i haven’t looked...

# kotlin-native

[jrod]

just refreshed my memory on stuff i haven’t looked at since ObjC days. Int on iOS is arch dependent and a bunch of articles seem to recommend using Int despite that all iPhones and iPads since 2013 and Watches since 2015 are now 64-bit.

So….assuming I don’t want to burden API callers with the difference, is there a smart way to pass Swift Int down and handle it appropriately in the following case?

let value = 5 // value is of type Int, so platform dependent

print("before: \(value)")
print("after: \(HelloKt.plusplus(value: value))")
// Cannot convert value of type 'Int' to expected argument type 'Int32'

in commonMain:

fun plusplus(value: Int): Int {
    return value + 1
}

fun plusplus(value: Long): Long {
    return value + 1
}

map to

+ (int32_t)plusplusValue__:(int32_t)value __attribute__((swift_name("plusplus(value__:)")));
+ (int64_t)plusplusValue___:(int64_t)value __attribute__((swift_name("plusplus(value___:)")));

respectively

in iosMain:

fun plusplus(value: integer_t): integer_t {
    return value + 1
}

fun plusplus(value: NSInteger): NSInteger {
    return value + 1
}

map to

public typealias NSInteger = kotlin.Long // 64 bit signed
public typealias integer_t = <http://kotlin.Int|kotlin.Int> // 32 bit signed

respectively

Any ideas?

[russhwolf]

One trick when hitting NSInteger APIs in obj-c is to use convert() at the obj-c/kotlin interface which can help make APIs size-agnostic. See eg https://github.com/russhwolf/multiplatform-settings/blob/master/multiplatform-settings/src/iosMain/kotlin/com/russhwolf/settings/AppleSettings.kt#L83-L97 which is used for all iOS variants

[jrod]

nice, that works from Kotlin to Obj-C boundaries, unfortunately i’m trying the other direction: from Obj-C to Kotlin