diff --git a/datastore/threadbackend.nim b/datastore/threadbackend.nim
index 476ebfe..47c7729 100644
--- a/datastore/threadbackend.nim
+++ b/datastore/threadbackend.nim
@@ -26,10 +26,14 @@ type
     Error
 
   ThreadResult*[T: DataBuffer | void | bool | ThreadDatastorePtr] = object
-    state*: ThreadResultKind
     signal*: ThreadSignalPtr
-    value*: T
-    error*: CatchableErrorBuffer
+    case state*: ThreadResultKind
+    of ThreadResultKind.NotReady:
+      discard
+    of ThreadResultKind.Success:
+      value*: T
+    of ThreadResultKind.Error:
+      error*: CatchableErrorBuffer
 
   TResult*[T] = SharedPtr[ThreadResult[T]]
 
@@ -50,25 +54,37 @@ proc newThreadResult*[T](
     res[].signal = signal.get()
   ok res
 
+proc success*[T](ret: TResult[T], value: T) =
+  {.cast(uncheckedAssign).}:
+    ret[].state = ThreadResultKind.Success
+    ret[].value = value
+
+proc success*[T: void](ret: TResult[T]) =
+  {.cast(uncheckedAssign).}:
+    ret[].state = ThreadResultKind.Success
+
+proc failure*[T](ret: TResult[T], err: ref CatchableError) =
+  {.cast(uncheckedAssign).}:
+    ret[].state = ThreadResultKind.Error
+  ret[].error = err.toBuffer()
+
 proc hasTask*(
   ret: TResult[bool],
   tds: ThreadDatastorePtr,
   kb: KeyBuffer,
 ) =
   without key =? kb.toKey(), err:
-    ret[].state = Error
+    ret.failure(err)
+
   try:
     let res = waitFor tds[].ds.has(key)
     if res.isErr:
-      ret[].state = Error
-      ret[].error = res.error().toBuffer()
+      ret.failure(res.error())
     else:
-      ret[].state = Success
-      ret[].value = res.get()
+      ret.success(res.get())
     discard ret[].signal.fireSync()
   except CatchableError as err:
-    ret[].state = Error
-    ret[].error = err.toBuffer()
+    ret.failure(err)
 
 proc has*(
   ret: TResult[bool],
@@ -88,17 +104,14 @@ proc getTask*(
   try:
     let res = waitFor tds[].ds.get(key)
     if res.isErr:
-      ret[].state = Error
-      ret[].error = res.error().toBuffer()
+      ret.failure(res.error())
     else:
       let db = DataBuffer.new res.get()
-      ret[].state = Success
-      ret[].value = db
+      ret.success(db)
 
     discard ret[].signal.fireSync()
   except CatchableError as err:
-    ret[].state = Error
-    ret[].error = err.toBuffer()
+    ret.failure(err)
 
 proc get*(
   ret: TResult[DataBuffer],
@@ -123,10 +136,9 @@ proc putTask*(
   let res = (waitFor tds[].ds.put(key, data)).catch
   # print "thrbackend: putTask: fire", ret[].signal.fireSync().get()
   if res.isErr:
-    ret[].state = Error
-    ret[].error = res.error().toBuffer()
+    ret.failure(res.error())
   else:
-    ret[].state = Success
+    ret.success()
 
   discard ret[].signal.fireSync()
 
@@ -154,10 +166,9 @@ proc deleteTask*(
   let res = (waitFor tds[].ds.delete(key)).catch
   # print "thrbackend: putTask: fire", ret[].signal.fireSync().get()
   if res.isErr:
-    ret[].state = Error
-    ret[].error = res.error().toBuffer()
+    ret.failure(res.error())
   else:
-    ret[].state = Success
+    ret.success()
 
   discard ret[].signal.fireSync()