> On Dec 14, 2017, at 12:51 AM, Inder Kumar Rathore . <[email protected]>
> wrote:
>
> class MyClass {
> private var myDict = [String : String]()
>
> func addMemebr() {
> self.myDict["key"] = "value" // Ok for me
> }
>
> func anotherFunc() {
> self.myDict = [String : String]() // Not okay for me, I don't want any
> code to do this within the class
> }
> }
If you want code to be able to insert, but not delete from or otherwise freely
change, the dictionary value, you could provide a wrapper type for myDict that
provides a restricted mutation API:
struct InsertOnlyDictionary {
private(set) var value = [String: String]()
mutating func insert(_ k: String, _ v: String) {
value[k] = v
}
}
// Code outside of InsertOnlyDictionary can read its `value`, but can only
modify it by its `insert` API
class MyClass {
private var myDict = InsertOnlyDictionary()
func addMember() {
self.myDict.insert("key", "value")
}
}
-Joe
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