Copy Int to UnsafeMutablePointer

Question

I have an Int which I want to copy to a pointer of type UnsafeMutablePointer<Int32>?

I tried to cast it to Data and then copy it, but the copy function param is of type UnsafeMutablePointer<UInt8>

This is what I've tried:

var sizePointer: UnsafeMutablePointer<Int32>?
var numOfBytes = 100
var sizeData = Data(bytes: &(numOfBytes), count: MemoryLayout<Int>.size)
//What's now? How to copy it to the pointer?
//sizeData.copyBytes(to: size, count: MemoryLayout<Int>.size) not working

Edit:

I have the following function, that gets a pointer. I need to copy the int to that address.

func f(pointer: UnsafeMutablePointer<Int32>?) {
    var numOfBytes = 100
    //copy numOfBytes  to the pointer's address
}

score 0 · Accepted Answer · answered Feb 27 '17 at 17:22

0

If you're just trying to call a function which expects an argument of type UnsafeMutablePointer<Int32>, then it's as simple as this:

func f(_ i: UnsafeMutablePointer<Int32>) {
    print(i.pointee)
}

var x = Int32()
f(&x)

answered Feb 27 '17 at 17:22

Alexander

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In that example lets say I want to copy x to the address pointed by i (where i is already malloced somewhere else). – Witterquick Feb 27 '17 at 20:30
So the equivalent of the C code `*i = x;`? In Swift, that would be `i.pointee = x` – Alexander Feb 27 '17 at 21:39
Yes, but I want the value to be copied (since it's defined at a local function). – Witterquick Feb 28 '17 at 13:49
Roee84 Ints are structs, which are value types. They're always copied when assigned – Alexander Feb 28 '17 at 15:20
Well, it was just an example. I want to *copy* Data to the pointer's address, but thank you and sorry for all the mess ;) – Witterquick Feb 28 '17 at 15:28
Well then ask a question that asks about copying data. – Alexander Feb 28 '17 at 15:29

Copy Int to UnsafeMutablePointer

1 Answers1