extension.swift

public extension CollectionType where Generator.Element == NSIndexPath
{
	func indexPathsWithSectionModified(by modifier: Int) -> [NSIndexPath]
	{
		var modifiedIndexPaths = [NSIndexPath]()
		
		for indexPath in self
		{
			let modifiedIndexPath = NSIndexPath(forItem: indexPath.item, inSection: indexPath.section + modifier)
			modifiedIndexPaths.append(modifiedIndexPath)
		}
		
		return modifiedIndexPaths
	}
	
	func indexPathsWithItemModified(by modifier: Int) -> [NSIndexPath]
	{
		var modifiedIndexPaths = [NSIndexPath]()
		
		for indexPath in self
		{
			let modifiedIndexPath = NSIndexPath(forItem: indexPath.item + modifier, inSection: indexPath.section)
			modifiedIndexPaths.append(modifiedIndexPath)
		}
		
		return modifiedIndexPaths
	}
}