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How Does Parameter Type (void *) In Objective-C Translate To UnsafePointer<()> In Swift?


How Does Parameter Type (void *) In Objective-C Translate To UnsafePointer<()> In Swift?

By : Hüséyinn Kadir
Date : November 17 2020, 04:28 AM
should help you out <...> is a generic specifier. It resolves the generic placeholder of the generic type to whose name it is appended.
For example, Array is a generic, where the placeholder is its element type. So Array is the type of an array whose generic placeholder is specified as being a String - meaning, an Array whose elements are strings. You may say [String], but Array is equally valid.
code :


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How to pass parameter of type UnsafeMutablePointer<UnsafePointer<Void>>

How to pass parameter of type UnsafeMutablePointer<UnsafePointer<Void>>


By : Srikanth R
Date : March 29 2020, 07:55 AM
may help you . You can simply use a Swift dictionary of type [ NSString : AnyObject ], which is automatically bridged to NSDictionary or CFDictionary. Note that you don't need CFStringRef either.
code :
let font = CTFontCreateWithName("Courier", 25.0, nil)
let attributes : [ NSString : AnyObject ] = [ kCTFontAttributeName : font ]
let attrString = CFAttributedStringCreate(nil, "Hello", attributes)
let attrString = NSAttributedString(string: "Hello", attributes: attributes)
let font = CTFontCreateWithName("Courier", 25.0, nil)
var keys = [ unsafeAddressOf(kCTFontAttributeName) ]
var values = [ unsafeAddressOf(font) ]
var keyCallbacks = kCFTypeDictionaryKeyCallBacks
var valueCallbacks = kCFTypeDictionaryValueCallBacks
let attributes = CFDictionaryCreate(nil, &keys, &values, 1, &keyCallbacks, &valueCallbacks)
let attrString = CFAttributedStringCreate(nil, "Hello", attributes)
converting ObjC to Swift - UnsafePointer<Void> not convertible to struct type

converting ObjC to Swift - UnsafePointer<Void> not convertible to struct type


By : Jon327
Date : March 29 2020, 07:55 AM
should help you out
Is it because I'm doing a check on the message type in the if statement?
code :
let message = UnsafePointer<Message>(data.bytes).memory
Swift: cannot convert value of type 'Self' to expected argument type 'UnsafePointer<Void>'

Swift: cannot convert value of type 'Self' to expected argument type 'UnsafePointer<Void>'


By : gouzipower
Date : March 29 2020, 07:55 AM
I wish did fix the issue. NSData(bytes:, length:) takes an UnsafePointer as first parameter, and you cannot pass an arbitrary SequenceType here.
You can pass an Array which would be passed as the address of the first array element. It is however not guaranteed that Array elements are stored in contiguous memory.
code :
extension Array where Element : IntegerType {
    var nsdata : NSData {
        return self.withUnsafeBufferPointer {
            NSData(bytes: $0.baseAddress, length: self.count * strideof(Element))
        }
    }
}

let input:[UInt8] = [0x60, 0x0D, 0xF0, 0x0D]
print(input.nsdata) // <600df00d>
extension Array where Element == UInt8 { }
// error: same-type requirement makes generic parameter 'Element' non-generic
let data = Array(myUInt8sequence).nsdata
Swift - Cannot convert value of type 'UnsafePointer<Any>' to expected argument type 'UnsafePointer<_>'

Swift - Cannot convert value of type 'UnsafePointer<Any>' to expected argument type 'UnsafePointer<_>'


By : Praveen Raj
Date : March 29 2020, 07:55 AM
fixed the issue. Will look into that further It's pointer that it is complaining about. You need to cast it. Here's an example usage, part of creating an MD5 hash:
code :
    var rawBytes = [UInt8](repeating: 0, count: Int(CC_MD5_DIGEST_LENGTH))
    let _ = data.withUnsafeBytes { (bytes: UnsafePointer<UInt8>) in
        CC_MD5(bytes, CC_LONG(data.count), &rawBytes)
    }
Cannot convert value of type 'CFString' to expected argument type 'UnsafePointer<Void>' (aka 'UnsafePointer<()&

Cannot convert value of type 'CFString' to expected argument type 'UnsafePointer<Void>' (aka 'UnsafePointer<()&


By : Thomas
Date : March 29 2020, 07:55 AM
will help you I am getting a build error, when I define the line , Try
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