What is 'a in F# [duplicate]

Question

While learning F# and reading this page, I found this code:

type MyGenericClass<'a> (x: 'a) =
   do printfn "%A" x

I did not understand the meaning of 'a is it related any how to lifetime concept at rust or something completely different?

Answer 1

'a is a type parameter, such as T in List<T>. The F# syntax for type parameters is to preface the name of the parameter with the tick mark. In your example, this means that the parameter x can be any type, and it will create a MyGenericClass of that generic type. For example, if you called new MyGenericClass(3), you would get a MyGenericClass<int>.