class ca{
var count = 1;
static var instance:ca = ca();
class func GetInstance()->ca{
return instance;
}
}
var a = ca.GetInstance();
var b = ca.GetInstance();
a.count = 2;
println("\(a.count),\(b.count)");//2,2
原文：http://blog.csdn.net/crazyeveryday/article/details/46594377