有什么方法可以优化 Swift 中的结构复制？

Question

I'm developing an iOS app and have the following data model:

struct Student {
    var name: String?
    var age: UInt?
    var hobbies: String?
    ...
}

This model is used as the data source in one view controller, where each property value will be filled in an UITextfield instance so that the user can edit a student's information. Every time a user finishes typing an item, eg the name, the new value will override the old model's corresponding property.

The problem is, since struct is a value type instead of a reference type, a new model instance is generated every time I assign a new property value to it. There may be above 20 properties in my model and I think so many copies are quite a waste. For some reasons I'm not allowed to use class . Is there any way to optimize this? Will these copies cause any performance issues?

Answer 1

you can create a func with mutating keyword like below

 struct Point {
      var x = 0.0
      mutating func add(_ t: Double){
        x += t
     }
   }

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