Using GLKMath from GLKit in Swift

Question

So I'm using a book called iOS Games by tutorials from Ray Wenderlich and trying to utilize some of the objective-C code found there to make the accelerometer control of a character in my game work. Instead of Objective-C though, I want to use Swift. I ran into an issue when trying to create a var of type GLKVector3, which represents a 3D vector. When I type in:

var raw:GLKVector3 = GLKVector3Make(irrelevant stuff)

I get the following error:

use of module GLKVector3 as type.

I have an import at the top of my swift file for GLKit:

import GLKit

Any ideas how I can get the functionality from the GLKMath files to use in my program?

Answer 1

Swift has added union support in version 1.2. The fields in imported unions are read-only, even if declared with var, but can be passed to and from C functions as necessary.

The release notes for Swift 1.2 imply that the fields may not be accessible at all, but they are still readable for at least the GLKit types:

Swift can now partially import C aggregates containing unions, bitfields, SIMD vector types, and other C language features that are not natively supported in Swift. The unsupported fields will not be accessible from Swift, but C and Objective-C APIs that have arguments and return values of these types can be used in Swift. This includes the Foundation NSDecimal type and the GLKit GLKVector and GLKMatrix types, among others.