[<StructuralEquality;StructuralComparison>]
type SomeType = {
    Value : int
}

let someTypeAsIEquatable = { Value = 3 } :> System.IEquatable<SomeType>
someTypeAsIEquatable.Equals({Value = 3}) |> ignore // calls Equals(SomeType) directly

{ Value = 3 }.Equals({Value = 4})

public struct Vector2f : IEquatable<Vector2f>

[<Struct;CustomEquality;NoComparison>]
type MyVal =
    val X : int
    new(x) = { X = x }
    override this.Equals(yobj) =
        match yobj with
        | :? MyVal as y -> y.X = this.X
        | _ -> false
    interface System.IEquatable<MyVal> with
        member this.Equals(other) =
            other.X = this.X

[<Struct>]
type MyVal =
    val X : int
    new(x) = { X = x }

for i in 0 .. 1000000 do
      (MyVal(i) = MyVal(i + 1)) |> ignore;;
Réel : 00:00:00.008, Processeur : 00:00:00.015, GC gén0: 4, gén1: 1, gén2: 0