sequence for generate int32 identifiers in Swift

IdSequence.swift

//
//  IdGenerator.swift
//  Created by Stefan Böther on 21.12.15.
//
import Foundation

class IdSequence : SequenceType {

    func generate() -> AnyGenerator<Int32> {
        var value : Int32 = 0
        return anyGenerator {
            return OSAtomicIncrement32(&value)
        }
    }
}