diff --git a/library/PrimitiveExtras/Pure.hs b/library/PrimitiveExtras/Pure.hs
new file mode 100644
--- /dev/null
+++ b/library/PrimitiveExtras/Pure.hs
@@ -0,0 +1,11 @@
+module PrimitiveExtras.Pure
+where
+
+import PrimitiveExtras.Prelude
+import PrimitiveExtras.Types
+import qualified PrimitiveExtras.UnliftedArray as A
+
+
+{-| Get length of the outer dimension of a primitive multi array -}
+primMultiArrayOuterLength :: PrimMultiArray a -> Int
+primMultiArrayOuterLength (PrimMultiArray outerDimension) = sizeofUnliftedArray outerDimension
diff --git a/primitive-extras.cabal b/primitive-extras.cabal
--- a/primitive-extras.cabal
+++ b/primitive-extras.cabal
@@ -1,7 +1,7 @@
 name:
   primitive-extras
 version:
-  0.1
+  0.1.1
 category:
   Primitive
 synopsis:
@@ -44,6 +44,7 @@
     PrimitiveExtras.IO
     PrimitiveExtras.Unfold
     PrimitiveExtras.Fold
+    PrimitiveExtras.Pure
   other-modules:
     PrimitiveExtras.UnliftedArray
     PrimitiveExtras.Prelude