anchor.diff:  open System.Collections.Generic
   open ExtCore
   
  +#if FX_ATLEAST_45
  +open System.Runtime.ExceptionServices
  +#endif
  +
   #nowarn "21" // recursive initialization
   #nowarn "40" // recursive initialization
   
  
positive.code:                         status <- Value res
                          res
                      with ex ->
                          status <- Exception ex
                          reraise ()
                  | Value value ->
                      value
                  | Exception ex ->
                      raise ex
  
      /// <summary>Gets a value that indicates whether the <see cref="LazyList`1"/> is empty.</summary>
      /// <remarks>Forces the evaluation of the first element of the stream if it is not already evaluated.</remarks>
  
negative.code:     static let undefinedValue =
          System.InvalidOperationException "The value of the LazyList cell is undefined."
          :> exn
          #if FX_ATLEAST_45
          |> ExceptionDispatchInfo.Capture
          #endif
          |> Exception
  
      //
  