diff --git a/safecopy.cabal b/safecopy.cabal
--- a/safecopy.cabal
+++ b/safecopy.cabal
@@ -1,5 +1,5 @@
 Name:                safecopy
-Version:             0.2
+Version:             0.3
 Synopsis:            Binary serialization with version control.
 Description:         An extension to Data.Binary with built-in version control.
 Category:            Data, Parsing
@@ -7,7 +7,8 @@
 License-file:        LICENSE
 Author:              David Himmelstrup
 Maintainer:          lemmih@gmail.com
-Build-Depends:       base, mtl, binary
+Build-Depends:       base, mtl, bytestring, containers, binary
+Build-Type:          Simple
 ghc-options:         -O -fglasgow-exts
 Hs-Source-Dirs:      src
 Exposed-Modules:
diff --git a/src/Data/SafeCopy/Instances.hs b/src/Data/SafeCopy/Instances.hs
--- a/src/Data/SafeCopy/Instances.hs
+++ b/src/Data/SafeCopy/Instances.hs
@@ -13,6 +13,7 @@
 import qualified Data.Set as Set
 
 import qualified Data.ByteString.Lazy.Char8 as L
+import qualified Data.ByteString.Char8 as B
 
 import Control.Monad
 
@@ -71,6 +72,8 @@
 instance SafeCopy Double where
     mode = Primitive; getCopy = contain $ get; putCopy = contain . put
 instance SafeCopy L.ByteString where
+    mode = Primitive; getCopy = contain $ get; putCopy = contain . put
+instance SafeCopy B.ByteString where
     mode = Primitive; getCopy = contain $ get; putCopy = contain . put
 instance SafeCopy Char where
     mode = Primitive; getCopy = contain $ get; putCopy = contain . put
diff --git a/src/Data/SafeCopy/Types.hs b/src/Data/SafeCopy/Types.hs
--- a/src/Data/SafeCopy/Types.hs
+++ b/src/Data/SafeCopy/Types.hs
@@ -95,3 +95,56 @@
 
 compareVersions :: Version a -> Version b -> Ordering
 compareVersions v1 v2 = compare (unVersion v1) (unVersion v2)
+
+
+
+{-
+
+class Versioned a where
+    typeVersion :: a -> Int
+
+data Test1 a = Test1 a
+data Test2 a = Test2 a
+
+data Sub1 = Sub1 Int; instance Versioned Sub1 where typeVersion _ = 1
+data Sub2 = Sub2 String; instance Versioned Sub2 where typeVersion _ = 2
+
+showVersion (Test1 s) = typeVersion s
+-}
+{-
+class HotSwap a where
+    hotVersion :: Version a
+    hotVersion = 0
+    destruct :: a -> (Int,ArgList)
+    construct :: (Int,ArgList) -> a
+
+data Test = Test Sub1 Sub2
+data Sub1 = Sub1
+data Sub2 = Sub2
+
+data ArgList = Nil | forall a. HotSwap a => a :+: ArgList
+
+infixr 5 :+:
+
+instance HotSwap Test where
+    destruct (Test a b) = (1, a :+: b :+: Nil)
+    construct (1, a :+: b :+: Nil) = Test (fromHot a) (fromHot b)
+
+instance HotSwap Sub1 where
+    destruct Sub1 = (1,Nil)
+    construct (1,Nil) = Sub1
+instance HotSwap Sub2 where
+    destruct Sub2= (1,Nil)
+    construct (1,Nil) = Sub2
+
+fromHot :: (HotSwap a, HotSwap b) => a -> b
+fromHot = undefined
+
+{-
+hotSwap :: forall a b. (HotSwap a, HotSwap b) => a -> b
+hotSwap inp
+    = let inpVersion = hotVersion :: Version a
+          outVersion = hotVersion :: Version b
+      in 
+-}
+-}