構造体に定義されている数だけ、CollectionViewCellを作る

実装

import UIKit

struct Pages {
    var viewControllers:[UIViewController] = []
}

class PageCollectionViewController: UICollectionViewController {
    
    var pages:Pages = Pages(){
        didSet {
            self.collectionView?.reloadData()
        }
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        
        let page1 = UIViewController()
        page1.view.backgroundColor = UIColor.yellowColor()
        self.pages.viewControllers.append(page1)
        
        let page2 = UIViewController()
        page2.view.backgroundColor = UIColor.blueColor()
        self.pages.viewControllers.append(page2)        
    }

    // MARK: - UICollectionViewDelegate
    
    override func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {

        return self.pages.viewControllers.count

    }
    
    override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {

        var cell = collectionView.dequeueReusableCellWithReuseIdentifier("PageCollectionViewCell", forIndexPath: indexPath) as UICollectionViewCell

        let view = self.pages.viewControllers[indexPath.row].view
                
        return cell
    }
    
}