Objective C long bridged to Swift as int?

Question

I can't bridge ObjectiveC long type into Swift.

//Swift
typealias Long = Int64
struct Item: Equatable {
    let itemId: Long
    ...
}

//ObjC
@interface MyObject : NSObject
@property(nonatomic, assign) long itemId;

//Try create object in Swift
Item(itemId: objCObject.itemId)

Error: Cannot convert value of type 'Int' to expected argument type 'Long' (aka 'Int64')

Does this answer your question? [Can I cast Int64 directly into Int?](https://stackoverflow.com/questions/32793460/can-i-cast-int64-directly-into-int) — pkamb, Sep 03 '20 at 13:32

Martin R · Accepted Answer · 2020-09-03T13:44:27.263

The (Objective-)C type long is bridged to Swift as CLong which is an alias for the Swift Int type. Int can be a 32-bit or 64-bit integer, depending on the platform.

In any case, you cannot cast or assign an Int64 directly to an Int, see also Can I cast Int64 directly into Int?.

If you want to keep the Swift itemID as a Int64 then you'll have to convert it to CLong when calling the Objective-C method. Alternatively you can change the Swift type to make it compatible:

struct Item: Equatable {
    let itemId: CLong
    ...
}

Another option would be to change the Objective-C type to

@property(nonatomic, assign) int64_t itemId;

which is then imported to Swift as Int64.

Objective C long bridged to Swift as int?

1 Answers1