几个SO帖子
like this处理相同的错误消息,但这些解决方案都不起作用.看起来这可能是一个误导性错误消息的情况.
谁知道为什么?
- func saveUser(user: User) {
- var userDicts = masterDict["users"] as! [[String:AnyObject]]
- let newDict = user.getDict()
- // Replace matching element with <newDict>
- let replaced = false
- masterDict["users"] = userDicts.map {
- if ($0["id"] as String! == user.getId()) {
- replaced = true
- return newDict
- } else {
- return $0 as [String:AnyObject]
- }
- }
- // If no match found,means must add new user
- if (!replaced) {
- userDicts.append(newDict)
- }
- }
不幸的是,swift并不完美,无法在任何时候推断出类型,这就是为什么你得到了模糊的参考.试试userDicts.map {val – > [String:AnyObject] in并为$换出$0这将明确告诉地图进来的值是[String:AnyObject],并且应该能够返回所述类型