ROP Result Discriminated Union interop with C#

Interop.fs

// the two-track type
type Result<'TSuccess,'TFailure> = 
    | Success of 'TSuccess
    | Failure of 'TFailure

type ResultInterop<'TSuccess, 'TFailure> = {
    IsSuccess : bool
    Success : 'TSuccess
    Failure : 'TFailure
}

let toResultInterop result =
    match result with
    | Success s -> { IsSuccess=true; Success=s; Failure=Unchecked.defaultof<_> }
    | Failure f -> { IsSuccess=false; Success=Unchecked.defaultof<_>; Failure=f }
    
module MyFSharpModule =
    let validate request = 
        if request.isValid then
            Success "Woot"
        else
            Failure "request not valid"
            
    let handleUpdateRequest request = 
        request
        |> validate
        |> toResultInterop
        
    
    

Usage.cs

public string Get(Request request)
{
	var result = MyFSharpModule.handleUpdateRequest(request);
	if (result.IsSuccess)
		return result.Success;
	else
		throw new Exception(result.Failure);
}