anchor.diff:              if List.isEmpty values
               then callee
               else callFunction com ctx None callee values
  -        if isStruct || isCopyableEntity com Set.empty ent || ent.FullName = Types.result
  +        if isCopyableEntity com Set.empty ent || ent.FullName = Types.result
           then expr
           else expr |> maybeWrapSmartPtr ent
   
  
positive.code:             makeRecord com ctx r isStruct values entRef genArgs
          | Fable.NewAnonymousRecord (values, fieldNames, genArgs, isStruct) -> makeTuple com ctx r isStruct values
          | Fable.NewUnion (values, tag, entRef, genArgs) ->
              let isStruct = (com.GetEntity entRef).IsValueType
              makeUnion com ctx r isStruct values tag entRef genArgs
  
      let calcVarAttrsAndOnlyRef com ctx (e: Fable.Expr) =
          let t = e.Type
  
negative.code:             else
                  fullName
  
      let makeUnion (com: IRustCompiler) ctx r values tag entRef genArgs =
          let ent = com.GetEntity(entRef)
          // let genArgs = transformGenArgs com ctx genArgs
          let unionCase = ent.UnionCases |> List.item tag
  