diff --git a/Data/Util.hs b/Data/Util.hs
new file mode 100644
--- /dev/null
+++ b/Data/Util.hs
@@ -0,0 +1,6 @@
+module Data.Util
+       ( unsafeSizeof
+       , strictUnsafeSizeof
+       )where
+
+import Data.Util.Size
diff --git a/Data/Util/Size.hs b/Data/Util/Size.hs
new file mode 100644
--- /dev/null
+++ b/Data/Util/Size.hs
@@ -0,0 +1,22 @@
+{-# LANGUAGE MagicHash,UnboxedTuples #-}
+module Data.Util.Size
+       ( unsafeSizeof
+       , strictUnsafeSizeof
+       )where
+
+import GHC.Exts
+import Foreign
+
+unsafeSizeof :: a -> Int
+unsafeSizeof a =
+  case unpackClosure# a of
+    (# x, ptrs, nptrs #) ->
+      sizeOf header + 
+      I# (sizeofByteArray# (unsafeCoerce# ptrs) +# 
+          sizeofByteArray# nptrs)
+  where
+    header :: Int
+    header = undefined
+
+strictUnsafeSizeof :: a -> Int
+strictUnsafeSizeof = (unsafeSizeof $!)
diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,30 @@
+Copyright (c)2011, Katsutoshi Itoh
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+
+    * Neither the name of Katsutoshi Itoh nor the names of other
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/Setup.hs b/Setup.hs
new file mode 100644
--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/data-util.cabal b/data-util.cabal
new file mode 100644
--- /dev/null
+++ b/data-util.cabal
@@ -0,0 +1,17 @@
+Name:                data-util
+Version:             0.1
+Synopsis:            utilities for handle data
+Description:         utilities for handle data
+Homepage:            https://github.com/cutsea110/data-util
+License:             BSD3
+License-file:        LICENSE
+Author:              Katsutoshi Itoh
+Maintainer:          cutsea110@gmail.com
+Category:            Data, Development, Utils
+Build-type:          Simple
+-- Extra-source-files:  
+Cabal-version:       >=1.2
+Library
+  Exposed-modules:     Data.Util, Data.Util.Size
+  Build-depends:       
+                     base >= 4.2 && < 4.3