Capturing a struct reference in a closure doesn't allow mutations to occur

Question

I am trying to see if I can use structs for my model and was trying this. When I call vm.testClosure(), it does not change the value of x and I am

Answer 1

Here is what Apple says about that.

Classes and Structures

A value type is a type that is copied when it is assigned to a variable or constant, or when it is passed to a function. [...] All structures and enumerations are value types in Swift

Methods

Structures and enumerations are value types. By default, the properties of a value type cannot be modified from within its instance methods.

However, if you need to modify the properties of your structure or enumeration within a particular method, you can opt in to mutating behaviour for that method. The method can then mutate (that is, change) its properties from within the method, and any changes that it makes are written back to the original structure when the method ends. The method can also assign a completely new instance to its implicit self property, and this new instance will replace the existing one when the method ends.

Taken from here