Hi,

In F# I have a function that returns System.Linq.Expression instances:

and System.Object with
  member this.ToExpression() = 
    match this with
    | :? System.Int32 -> Expression.Constant(this) :> Expression
    | :? System.Boolean -> Expression.Constant(this) :> Expression
    | :? Tml.Runtime.Seq as s -> s.ToExpression()
    | _ -> failwith "bad expression"

If I omit the type coercions on the return values F# will infer the return type of the function to ConstantExpression. My first thought was to explicitly mark the return type as being : #Expression, but that didn't work. Is there a more elegant way of doing this that doesn't involve manually casting return types to the most generic type?

Thanks.