我怎样才能将 &#39;[Int]&#39; 也转换为 &#39;UnsafeMutablePointer<Int32> ?&#39;?

Question

I have a variable called time_diff in an app I'm making. I need to pass it into an obj-c function that takes UnsafeMutablePointer?.

Swift:

var time_diff = [Int](repeating: 0, count: MAX_NODE)

Obj-C Function:

- (instancetype) initWithRawDataX:(float *)x Y:(float*)y pressure:(float *)p time_diff:(int *)time penColor:(UInt32)penColor penThickness:(NSUInteger)thickness startTime:(UInt64)start_at size:(int)size normalizer:(float)inputScale

Answer 1

See Manual Memory Management in Apple's docs: https://developer.apple.com/documentation/swift/swift_standard_library/manual_memory_management .

In this case, if the function is imported into Swift as having UnsafeMutablePointer<Int32> for the type of time_diff , you should declare the array in swift as [Int32] instead of [Int] . Then pass it as &time_diff (an inout argument).