Question

I’ve just started learning F#.

I wonder how can I determine whether the argument of a function is a tuple?

let tuple = (1, 2)
let notTuple = 3

let isTuple t =  // returns 'true' if t is a tuple, 'false' otherwise

printfn "%b" isTuple tuple      // true
printfn "%b" isTuple notTuple   // false

Answer 1

FSharpType.IsTuple^[MSDN] does this.

let isTuple value = 
  match box value with
  | null -> false
  | _ -> FSharpType.IsTuple(value.GetType())