How to correctly initialize an UnsafePointer in Swift?

Question

I\'m trying to use CTFontCreatePathForGlyph(font: CTFont?, glyph: CGGlyph, transform: CConstPointer):

let myFont = CTFontCr         


        

Answer 1

The simplest solution is using withUnsafePointer function:

let myFont = CTFontCreateWithName("Helvetica", 12, nil)
let myGlyph = CTFontGetGlyphWithName(myFont, "a")
var myTransform = CGAffineTransformIdentity

var path = withUnsafePointer(&myTransform) { (pointer: UnsafePointer<CGAffineTransform>) -> (CGPath) in
    return CTFontCreatePathForGlyph(myFont, myGlyph, pointer)
}

The initialize is not a constructor. You would have to alloc a new memory using UnsafePointer<T>.alloc, then initialize and then dealloc. Function withUnsafePointer does that all for you.

Note that myTransform cannot be a constant (var not let) otherwise you cannot use it for an inout param (&myTransform).