diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+# 1.0.1
+
+* Relax constraint on `computeInto` by removing requirement for `Size`
+* Fix `BL`, which due to a forgotten `seq` was not lazy.
+
 # 1.0.0
 
 * Addition of `sumArrays'`, `sumArraysM` and `productArrays'`, `productArraysM`.
diff --git a/massiv.cabal b/massiv.cabal
--- a/massiv.cabal
+++ b/massiv.cabal
@@ -1,5 +1,5 @@
 name:                massiv
-version:             1.0.0.0
+version:             1.0.1.0
 synopsis:            Massiv (Массив) is an Array Library.
 description:         Multi-dimensional Arrays with fusion, stencils and parallel computation.
 homepage:            https://github.com/lehins/massiv
@@ -107,15 +107,16 @@
   main-is:          doctests.hs
   build-depends: base
                , doctest >=0.15
-               , QuickCheck
-               , massiv
-               , mersenne-random-pure64
-               , random >= 1.2.0
-               , mwc-random >= 0.15.0.1
-               , splitmix >= 0.0.1
-               , template-haskell
+  if impl(ghc >= 8.2) && impl(ghc < 8.10)
+    build-depends: QuickCheck
+                 , massiv
+                 , mersenne-random-pure64
+                 , random >= 1.2.0
+                 , mwc-random >= 0.15.0.1
+                 , splitmix >= 0.0.1
   default-language:    Haskell2010
 
 source-repository head
   type:     git
   location: https://github.com/lehins/massiv
+  subdir:   massiv
diff --git a/src/Data/Massiv/Array/Manifest/Boxed.hs b/src/Data/Massiv/Array/Manifest/Boxed.hs
--- a/src/Data/Massiv/Array/Manifest/Boxed.hs
+++ b/src/Data/Massiv/Array/Manifest/Boxed.hs
@@ -85,8 +85,30 @@
 -- Boxed Lazy --
 ----------------
 
--- | Array representation for Boxed elements. This data structure is lazy with respect to
--- its elements, but is strict with respect to the spine.
+-- | Array representation for Boxed elements. This data structure is lazy with
+-- respect to its elements, but is strict with respect to the spine.
+--
+-- ====__Example__
+--
+-- Memoized version of a factorial that relies on laziness. Note that
+-- computing memoized factorial of a million would likely overflow memory.
+--
+-- >>> import Data.Massiv.Array as A
+-- >>> :{
+-- mkMemoFactorial :: Int -> (Int -> Integer)
+-- mkMemoFactorial n =
+--   let arr = makeVectorR BL Seq (Sz1 n) fact
+--       fact i | i == 0 = 1
+--              | otherwise = (arr ! (i - 1)) * toInteger i
+--   in (arr !)
+-- :}
+--
+-- >>> let fact = mkMemoFactorial 1000001
+-- >>> fact 50
+-- 30414093201713378043612608166064768844377641568960512000000000000
+-- >>> length $ show $ fact 5000
+-- 16326
+--
 data BL = BL deriving Show
 
 data instance Array BL ix e = BLArray { blComp   :: !Comp
@@ -177,7 +199,7 @@
                 SafeSz . A.sizeofMutableArray, A.readArray) ma (i + o)
   {-# INLINE unsafeLinearRead #-}
 
-  unsafeLinearWrite (MBLArray _sz o ma) i e = e `seq`
+  unsafeLinearWrite (MBLArray _sz o ma) i e =
     INDEX_CHECK("(Manifest BL ix e).unsafeLinearWrite",
                 SafeSz . A.sizeofMutableArray, A.writeArray) ma (i + o) e
   {-# INLINE unsafeLinearWrite #-}
diff --git a/src/Data/Massiv/Array/Mutable.hs b/src/Data/Massiv/Array/Mutable.hs
--- a/src/Data/Massiv/Array/Mutable.hs
+++ b/src/Data/Massiv/Array/Mutable.hs
@@ -409,14 +409,15 @@
 --
 -- @since 0.1.3
 computeInto ::
-     (Size r', Load r' ix' e, Manifest r e, Index ix, MonadIO m)
+     (Load r' ix' e, Manifest r e, Index ix, MonadIO m)
   => MArray RealWorld r ix e -- ^ Target Array
   -> Array r' ix' e -- ^ Array to load
   -> m ()
 computeInto !mArr !arr =
   liftIO $ do
-    unless (totalElem (sizeOfMArray mArr) == totalElem (size arr)) $
-      throwM $ SizeElementsMismatchException (sizeOfMArray mArr) (size arr)
+    let sz = outerSize arr
+    unless (totalElem (sizeOfMArray mArr) == totalElem sz) $
+      throwM $ SizeElementsMismatchException (sizeOfMArray mArr) sz
     withMassivScheduler_ (getComp arr) $ \scheduler ->
       stToPrim $ iterArrayLinearST_ scheduler arr (unsafeLinearWrite mArr)
 {-# INLINE computeInto #-}
diff --git a/src/Data/Massiv/Vector.hs b/src/Data/Massiv/Vector.hs
--- a/src/Data/Massiv/Vector.hs
+++ b/src/Data/Massiv/Vector.hs
@@ -1131,7 +1131,7 @@
 sunfoldrN n f = DSArray . S.unfoldrN n f
 {-# INLINE sunfoldrN #-}
 
--- | /O(n)/ - Same as `unfoldr`, but with monadic generating function.
+-- | /O(n)/ - Same as `sunfoldr`, but with monadic generating function.
 --
 -- ==== __Examples__
 --
@@ -1148,7 +1148,7 @@
 sunfoldrM f = fromStepsM . S.unfoldrM f
 {-# INLINE sunfoldrM #-}
 
--- | /O(n)/ - Same as `unfoldrN`, but with monadic generating function.
+-- | /O(n)/ - Same as `sunfoldrN`, but with monadic generating function.
 --
 -- ==== __Examples__
 --
@@ -1174,7 +1174,7 @@
 {-# INLINE sunfoldrNM #-}
 
 
--- | /O(n)/ - Similar to `unfoldrN`, except the length of the resulting vector will be exactly @n@
+-- | /O(n)/ - Similar to `sunfoldrN`, except the length of the resulting vector will be exactly @n@
 --
 -- ==== __Examples__
 --
@@ -1187,7 +1187,7 @@
 sunfoldrExactN n f = fromSteps . S.unfoldrExactN n f
 {-# INLINE sunfoldrExactN #-}
 
--- | /O(n)/ - Similar to `unfoldrNM`, except the length of the resulting vector will be exactly @n@
+-- | /O(n)/ - Similar to `sunfoldrNM`, except the length of the resulting vector will be exactly @n@
 --
 -- ==== __Examples__
 --
@@ -1697,8 +1697,8 @@
 
 
 
--- | Zip two arrays in a row-major order together together into a flat vector. Resulting
--- length of a vector will be the smallest number of elements of the supplied arrays.
+-- | Zip two vectors together into a vector. The length of a resulting vector will
+-- be the smallest length of the supplied vectors.
 --
 -- ==== __Examples__
 --
@@ -1711,7 +1711,8 @@
 szip = szipWith (,)
 {-# INLINE szip #-}
 
--- |
+-- | Zip three vectors together into a vector. The length of a resulting vector will
+-- be the smallest length of the supplied vectors.
 --
 -- @since 0.5.0
 szip3 ::
@@ -1723,7 +1724,8 @@
 szip3 = szipWith3 (,,)
 {-# INLINE szip3 #-}
 
--- |
+-- | Zip four vectors together into a vector. The length of a resulting vector will
+-- be the smallest length of the supplied vectors.
 --
 -- @since 0.5.0
 szip4 ::
@@ -1737,7 +1739,8 @@
 szip4 = szipWith4 (,,,)
 {-# INLINE szip4 #-}
 
--- |
+-- | Zip five vectors together into a vector. The length of a resulting vector will
+-- be the smallest length of the supplied vectors.
 --
 -- @since 0.5.0
 szip5 ::
@@ -1752,7 +1755,8 @@
 szip5 = szipWith5 (,,,,)
 {-# INLINE szip5 #-}
 
--- |
+-- | Zip six vectors together into a vector. The length of a resulting vector will
+-- be the smallest length of the supplied vectors.
 --
 -- @since 0.5.0
 szip6 ::
@@ -1777,9 +1781,8 @@
 
 
 
-
-
--- |
+-- | Zip two vectors together with a binary function into a vector. The length
+-- of a resulting vector will be the smallest length of the supplied vectors.
 --
 -- ==== __Examples__
 --
@@ -1794,7 +1797,8 @@
 szipWith f v1 v2 = fromSteps $ S.zipWith f (S.toStream v1) (S.toStream v2)
 {-# INLINE szipWith #-}
 
--- |
+-- | Zip three vectors together with a ternary function into a vector. The length
+-- of a resulting vector will be the smallest length of the supplied vectors.
 --
 -- @since 0.5.0
 szipWith3 ::
@@ -1808,7 +1812,8 @@
 szipWith3 f v1 v2 v3 = fromSteps $ S.zipWith3 f (S.toStream v1) (S.toStream v2) (S.toStream v3)
 {-# INLINE szipWith3 #-}
 
--- |
+-- | Zip four vectors together with a quaternary function into a vector. The length
+-- of a resulting vector will be the smallest length of the supplied vectors.
 --
 -- @since 0.5.0
 szipWith4 ::
@@ -1824,7 +1829,8 @@
   fromSteps $ S.zipWith4 f (S.toStream v1) (S.toStream v2) (S.toStream v3) (S.toStream v4)
 {-# INLINE szipWith4 #-}
 
--- |
+-- | Zip five vectors together with a quinary function into a vector. The length
+-- of a resulting vector will be the smallest length of the supplied vectors.
 --
 -- @since 0.5.0
 szipWith5 ::
@@ -1842,7 +1848,8 @@
   S.zipWith5 f (S.toStream v1) (S.toStream v2) (S.toStream v3) (S.toStream v4) (S.toStream v5)
 {-# INLINE szipWith5 #-}
 
--- |
+-- | Zip six vectors together with a senary function into a vector. The length
+-- of a resulting vector will be the smallest length of the supplied vectors.
 --
 -- @since 0.5.0
 szipWith6 ::
@@ -1874,7 +1881,9 @@
     (S.toStream v6)
 {-# INLINE szipWith6 #-}
 
--- |
+-- | Just like `szipWith`, zip two vectors together, but with an index aware
+-- function. The length of a resulting vector will be the smallest length of the
+-- supplied vectors.
 --
 -- ==== __Examples__
 --
@@ -1889,7 +1898,9 @@
 sizipWith f v1 v2 = fromSteps $ S.zipWith (uncurry f) (S.toStreamIx v1) (S.toStream v2)
 {-# INLINE sizipWith #-}
 
--- |
+-- | Just like `szipWith3`, zip three vectors together, but with an index aware
+-- function. The length of a resulting vector will be the smallest length of the
+-- supplied vectors.
 --
 -- @since 0.5.0
 sizipWith3 ::
@@ -1904,7 +1915,9 @@
   fromSteps $ S.zipWith3 (uncurry f) (S.toStreamIx v1) (S.toStream v2) (S.toStream v3)
 {-# INLINE sizipWith3 #-}
 
--- |
+-- | Just like `szipWith4`, zip four vectors together, but with an index aware
+-- function. The length of a resulting vector will be the smallest
+-- length of the supplied vectors.
 --
 -- @since 0.5.0
 sizipWith4 ::
@@ -1921,7 +1934,9 @@
   S.zipWith4 (uncurry f) (S.toStreamIx v1) (S.toStream v2) (S.toStream v3) (S.toStream v4)
 {-# INLINE sizipWith4 #-}
 
--- |
+-- | Just like `szipWith5`, zip five vectors together, but with an index aware
+-- function. The length of a resulting vector will be the smallest length of the
+-- supplied vectors.
 --
 -- @since 0.5.0
 sizipWith5 ::
@@ -1945,7 +1960,9 @@
     (S.toStream v5)
 {-# INLINE sizipWith5 #-}
 
--- |
+-- | Just like `szipWith6`, zip six vectors together, but with an index aware
+-- function. The length of a resulting vector will be the smallest length of the
+-- supplied vectors.
 --
 -- @since 0.5.0
 sizipWith6 ::
@@ -1978,7 +1995,9 @@
 {-# INLINE sizipWith6 #-}
 
 
--- |
+-- | Zip two vectors together with a binary monadic action into a vector. The
+-- length of a resulting vector will be the smallest length of the supplied
+-- vectors.
 --
 -- ==== __Examples__
 --
@@ -1993,7 +2012,9 @@
 szipWithM f v1 v2 = fromStepsM $ S.zipWithM f (toStreamM v1) (toStreamM v2)
 {-# INLINE szipWithM #-}
 
--- |
+-- | Zip three vectors together with a ternary monadic action into a vector. The
+-- length of a resulting vector will be the smallest length of the supplied
+-- vectors.
 --
 -- @since 0.5.0
 szipWith3M ::
@@ -2007,7 +2028,9 @@
 szipWith3M f v1 v2 v3 = fromStepsM $ S.zipWith3M f (toStreamM v1) (toStreamM v2) (toStreamM v3)
 {-# INLINE szipWith3M #-}
 
--- |
+-- | Zip four vectors together with a quaternary monadic action into a vector. The
+-- length of a resulting vector will be the smallest length of the supplied
+-- vectors.
 --
 -- @since 0.5.0
 szipWith4M ::
@@ -2023,7 +2046,9 @@
   fromStepsM $ S.zipWith4M f (toStreamM v1) (toStreamM v2) (toStreamM v3) (toStreamM v4)
 {-# INLINE szipWith4M #-}
 
--- |
+-- | Zip five vectors together with a quinary monadic action into a vector. The
+-- length of a resulting vector will be the smallest length of the supplied
+-- vectors.
 --
 -- @since 0.5.0
 szipWith5M ::
@@ -2047,7 +2072,9 @@
   S.zipWith5M f (toStreamM v1) (toStreamM v2) (toStreamM v3) (toStreamM v4) (toStreamM v5)
 {-# INLINE szipWith5M #-}
 
--- |
+-- | Zip six vectors together with a senary monadic action into a vector. The
+-- length of a resulting vector will be the smallest length of the supplied
+-- vectors.
 --
 -- @since 0.5.0
 szipWith6M ::
@@ -2081,7 +2108,9 @@
 {-# INLINE szipWith6M #-}
 
 
--- |
+-- | Just like `szipWithM`, zip two vectors together, but with an index aware
+-- monadic action. The length of a resulting vector will be the smallest length of the
+-- supplied vectors.
 --
 -- ==== __Examples__
 --
@@ -2097,7 +2126,9 @@
 {-# INLINE sizipWithM #-}
 
 
--- |
+-- | Just like `szipWith3M`, zip three vectors together, but with an index aware
+-- monadic action. The length of a resulting vector will be the smallest length of the
+-- supplied vectors.
 --
 -- @since 0.5.0
 sizipWith3M ::
@@ -2112,7 +2143,9 @@
   fromStepsM $ S.zipWith3M (uncurry f) (toStreamIxM v1) (toStreamM v2) (toStreamM v3)
 {-# INLINE sizipWith3M #-}
 
--- |
+-- | Just like `szipWith4M`, zip four vectors together, but with an index aware
+-- monadic action. The length of a resulting vector will be the smallest length of the
+-- supplied vectors.
 --
 -- @since 0.5.0
 sizipWith4M ::
@@ -2129,7 +2162,9 @@
   S.zipWith4M (uncurry f) (toStreamIxM v1) (toStreamM v2) (toStreamM v3) (toStreamM v4)
 {-# INLINE sizipWith4M #-}
 
--- |
+-- | Just like `szipWith6M`, zip five vectors together, but with an index aware
+-- monadic action. The length of a resulting vector will be the smallest length of the
+-- supplied vectors.
 --
 -- @since 0.5.0
 sizipWith5M ::
@@ -2159,7 +2194,9 @@
     (toStreamM v5)
 {-# INLINE sizipWith5M #-}
 
--- |
+-- | Just like `szipWith6M`, zip six vectors together, but with an index aware
+-- monadic action. The length of a resulting vector will be the smallest length of the
+-- supplied vectors.
 --
 -- ==== __Examples__
 --
@@ -2195,7 +2232,9 @@
 {-# INLINE sizipWith6M #-}
 
 
--- |
+-- | Similar to `szipWithM`, zip two vectors together with a binary monadic
+-- action, while discarding its result. The action will be invoked as many times as
+-- the length of the smallest vector.
 --
 -- ==== __Examples__
 --
@@ -2209,7 +2248,9 @@
 szipWithM_ f v1 v2 = S.zipWithM_ f (toStreamM v1) (toStreamM v2)
 {-# INLINE szipWithM_ #-}
 
--- |
+-- | Similar to `szipWith3M`, zip three vectors together with a ternary monadic
+-- action, while discarding its result. The action will be invoked as many times as
+-- the length of the smallest vector.
 --
 -- @since 0.5.0
 szipWith3M_ ::
@@ -2223,7 +2264,9 @@
 szipWith3M_ f v1 v2 v3 = S.zipWith3M_ f (toStreamM v1) (toStreamM v2) (toStreamM v3)
 {-# INLINE szipWith3M_ #-}
 
--- |
+-- | Similar to `szipWith4M`, zip four vectors together with a quaternary monadic
+-- action, while discarding its result. The action will be invoked as many times as
+-- the length of the smallest vector.
 --
 -- @since 0.5.0
 szipWith4M_ ::
@@ -2239,7 +2282,9 @@
   S.zipWith4M_ f (toStreamM v1) (toStreamM v2) (toStreamM v3) (toStreamM v4)
 {-# INLINE szipWith4M_ #-}
 
--- |
+-- | Similar to `szipWith5M`, zip five vectors together with a quinary monadic
+-- action, while discarding its result. The action will be invoked as many times as
+-- the length of the smallest vector.
 --
 -- @since 0.5.0
 szipWith5M_ ::
@@ -2262,7 +2307,9 @@
   S.zipWith5M_ f (toStreamM v1) (toStreamM v2) (toStreamM v3) (toStreamM v4) (toStreamM v5)
 {-# INLINE szipWith5M_ #-}
 
--- |
+-- | Similar to `szipWith6M`, zip six vectors together with a senary monadic
+-- action, while discarding its result. The action will be invoked as many times as
+-- the length of the smallest vector.
 --
 -- @since 0.5.0
 szipWith6M_ ::
@@ -2296,8 +2343,9 @@
 
 
 
-
--- |
+-- | Same as `szipWithM_`, zip two vectors together, but with an index aware
+-- monadic action. The action will be invoked as many times as the length of the
+-- smallest vector.
 --
 -- ==== __Examples__
 --
@@ -2312,7 +2360,9 @@
 {-# INLINE sizipWithM_ #-}
 
 
--- |
+-- | Same as `szipWith3M_`, zip three vectors together, but with an index aware
+-- monadic action. The action will be invoked as many times as the length of the
+-- smallest vector.
 --
 -- @since 0.5.0
 sizipWith3M_ ::
@@ -2326,7 +2376,9 @@
 sizipWith3M_ f v1 v2 v3 = S.zipWith3M_ (uncurry f) (toStreamIxM v1) (toStreamM v2) (toStreamM v3)
 {-# INLINE sizipWith3M_ #-}
 
--- |
+-- | Same as `szipWith4M_`, zip four vectors together, but with an index aware
+-- monadic action. The action will be invoked as many times as the length of the
+-- smallest vector.
 --
 -- @since 0.5.0
 sizipWith4M_ ::
@@ -2342,7 +2394,9 @@
   S.zipWith4M_ (uncurry f) (toStreamIxM v1) (toStreamM v2) (toStreamM v3) (toStreamM v4)
 {-# INLINE sizipWith4M_ #-}
 
--- |
+-- | Same as `szipWith5M_`, zip five vectors together, but with an index aware
+-- monadic action. The action will be invoked as many times as the length of the
+-- smallest vector.
 --
 -- @since 0.5.0
 sizipWith5M_ ::
@@ -2371,7 +2425,9 @@
     (toStreamM v5)
 {-# INLINE sizipWith5M_ #-}
 
--- |
+-- | Same as `szipWith6M_`, zip six vectors together, but with an index aware
+-- monadic action. The action will be invoked as many times as the length of the
+-- smallest vector.
 --
 -- @since 0.5.0
 sizipWith6M_ ::
@@ -2407,7 +2463,8 @@
 
 
 
--- | Strict left fold sequentially over a streamed array.
+-- | Streaming fold over an array in a row-major fashion with a left biased
+-- function and a strict accumulator.
 --
 -- ==== __Examples__
 --
diff --git a/tests/doctests.hs b/tests/doctests.hs
--- a/tests/doctests.hs
+++ b/tests/doctests.hs
@@ -1,7 +1,7 @@
 {-# LANGUAGE CPP #-}
 module Main where
 
-#if __GLASGOW_HASKELL__ >= 802 && __GLASGOW_HASKELL__ != 810
+#if __GLASGOW_HASKELL__ >= 802 && __GLASGOW_HASKELL__ < 810
 
 import Test.DocTest (doctest)