Any ​

The any type is a built-in type and is represented by the any keyword. It can be hold any data type and might be nil. Because its type is ambiguous at comptime, it can accept assignments from different types and, once assigned, can be reassigned with a different type.

It only supports equals (==) and not equals (!=) operators. Panics if type is uncomparable.

x == nil: true if any is nil, not checks whether data is nil
x == y: true if x and y is nil
x == y: true if x and y has same data type and returns true of equals operator of data type for two value

Supports casting to any type. You can get type-safe value of any with casting. For example:

let myAny: any = 10
let x = (int)(myAny)

any type protects itself against mutability if necessary. For example, you have slice value holds by any-typed variable. And your variable is immutable. So, if you cast your value to slice for assign to mutable variable, you will get error. Because of slice is mutable type, so it's breaking immutability.