How to convert between F# and C# tuples?

Question

I am writing an F# interop class to be used from C#. I thought that F# had an implicit conversion from .NET Tuple<> type (similar to IEnumerable treated as seq), so I wrote the following code:

type MyClass() = 
    member this.MyMethod (t: Tuple<int, int>) =
        let meaningOfLife (t : int * int) = 42
        meaningOfLife t

This code fails to compile with the following error: error FS0001: This expression was expected to have type int * int but here has type Tuple

Then how to convert tuples between C# and F# (and back)?

Both types are different. You could write meaningOfLife (t.item1, t.item2). — josejuan

sker sker · Accepted Answer · 2013-07-21T19:34:43

If you're targeting .NET 4.0 and above, you don't need to specify the object Tuple. F# tuples get automatically compiled to Tuple. You can use:

type MyClass() = 
  member this.MyMethod (t: int * int) =
    let meaningOfLife (t : int * int) = 42
    meaningOfLife t

And it should work fine from C#.

How to convert between F# and C# tuples?

1 Answers