diff --git a/Inj/Base.hs b/Inj/Base.hs
new file mode 100644
--- /dev/null
+++ b/Inj/Base.hs
@@ -0,0 +1,251 @@
+-- | 'Inj' instances for types from 'base'.
+
+{-# LANGUAGE
+    DefaultSignatures,
+    MultiParamTypeClasses,
+    FlexibleInstances,
+    FlexibleContexts,
+    TypeFamilies,
+    ScopedTypeVariables,
+    DataKinds,
+    TypeOperators,
+    UndecidableInstances
+#-}
+
+module Inj.Base () where
+
+import GHC.TypeLits
+import Control.Applicative
+import Control.Exception hiding (TypeError)
+import Control.Monad.ST
+import Data.Complex
+import Data.Fixed
+import Data.Functor.Compose
+import Data.Functor.Identity
+import Data.Int
+import Data.List.NonEmpty
+import Data.Monoid
+import Data.Ord
+import Data.Proxy
+import Data.Semigroup
+import Data.Word
+import Foreign.Ptr
+import GHC.Conc
+import GHC.Generics
+import GHC.Real
+import Numeric.Natural
+import Text.ParserCombinators.ReadP
+import Text.ParserCombinators.ReadPrec
+
+import Inj
+
+--------------------------------------------------------------------------------
+-- 'fromIntegral' is an injection from any @Integral p@ to any @Num a@.
+--------------------------------------------------------------------------------
+
+instance Integral p => Inj p Integer where
+  inj = toInteger
+
+-- | Throws 'Underflow'.
+instance Integral p => Inj p Natural where
+  inj = fromIntegral
+
+fromIntegralBounded ::
+  forall p a. (Integral a, Bounded a) => Integral p => p -> a
+fromIntegralBounded p
+  | p' < toInteger (minBound :: a) = throw Underflow
+  | p' > toInteger (maxBound :: a) = throw Overflow
+  | otherwise = fromInteger p'
+  where
+    p' = toInteger p
+
+-- | Throws 'Underflow' and 'Overflow'.
+instance Integral p => Inj p Int where
+  inj = fromIntegralBounded
+
+-- | Throws 'Underflow' and 'Overflow'.
+instance Integral p => Inj p Int8 where
+  inj = fromIntegralBounded
+
+-- | Throws 'Underflow' and 'Overflow'.
+instance Integral p => Inj p Int16 where
+  inj = fromIntegralBounded
+
+-- | Throws 'Underflow' and 'Overflow'.
+instance Integral p => Inj p Int32 where
+  inj = fromIntegralBounded
+
+-- | Throws 'Underflow' and 'Overflow'.
+instance Integral p => Inj p Int64 where
+  inj = fromIntegralBounded
+
+-- | Throws 'Underflow' and 'Overflow'.
+instance Integral p => Inj p Word where
+  inj = fromIntegralBounded
+
+-- | Throws 'Underflow' and 'Overflow'.
+instance Integral p => Inj p Word8 where
+  inj = fromIntegralBounded
+
+-- | Throws 'Underflow' and 'Overflow'.
+instance Integral p => Inj p Word16 where
+  inj = fromIntegralBounded
+
+-- | Throws 'Underflow' and 'Overflow'.
+instance Integral p => Inj p Word32 where
+  inj = fromIntegralBounded
+
+-- | Throws 'Underflow' and 'Overflow'.
+instance Integral p => Inj p Word64 where
+  inj = fromIntegralBounded
+
+-- | Throws 'Underflow' and 'Overflow'.
+instance Integral p => Inj p IntPtr where
+  inj = fromIntegralBounded
+
+-- | Throws 'Underflow' and 'Overflow'.
+instance Integral p => Inj p WordPtr where
+  inj = fromIntegralBounded
+
+--------------------------------------------------------------------------------
+-- 'realToFrac' is an injection from any @Real p@ to any @Fractional a@.
+--------------------------------------------------------------------------------
+
+instance (Inj Integer a, Real p) => Inj p (Ratio a) where
+  inj p = inj n :% inj d
+    where
+      n :% d = toRational p
+
+-- | Throws 'LossOfPrecision'.
+instance (HasResolution res, Real p) => Inj p (Fixed res) where
+  inj p
+    | denominator i == 1 = MkFixed (numerator i)
+    | otherwise = throw LossOfPrecision
+    where
+      i = toRational p * toRational res
+      res = resolution (Proxy :: Proxy res)
+
+-- | Injective only if the number is representable as 'Float'.
+instance Real p => Inj p Float where
+  inj = realToFrac
+
+-- | Injective only if the number is representable as 'Double'.
+instance Real p => Inj p Double where
+  inj = realToFrac
+
+instance (Num a, Inj p a) => Inj p (Complex a) where
+  inj p = inj p :+ 0
+
+--------------------------------------------------------------------------------
+-- 'pure' is often an injection into @Applicative f@.
+--------------------------------------------------------------------------------
+
+instance Inj p a => Inj p [a] where
+  inj = pure . inj
+
+instance Inj p a => Inj p (Maybe a) where
+  inj = pure . inj
+
+instance Inj p a => Inj p (IO a) where
+  inj = pure . inj
+
+instance Inj p a => Inj p (NonEmpty a) where
+  inj = pure . inj
+
+instance Inj p a => Inj p (ReadP a) where
+  inj = pure . inj
+
+instance Inj p a => Inj p (ReadPrec a) where
+  inj = pure . inj
+
+instance Inj p a => Inj p (Down a) where
+  inj = pure . inj
+
+instance Inj p a => Inj p (Product a) where
+  inj = pure . inj
+
+instance Inj p a => Inj p (Sum a) where
+  inj = pure . inj
+
+instance Inj p a => Inj p (Dual a) where
+  inj = pure . inj
+
+instance Inj p a => Inj p (Data.Monoid.Last a) where
+  inj = pure . inj
+
+instance Inj p a => Inj p (Data.Monoid.First a) where
+  inj = pure . inj
+
+instance Inj p a => Inj p (STM a) where
+  inj = pure . inj
+
+instance Inj p a => Inj p (Identity a) where
+  inj = pure . inj
+
+instance Inj p a => Inj p (ZipList a) where
+  inj = pure . inj
+
+instance Inj p a => Inj p (Option a) where
+  inj = pure . inj
+
+instance Inj p a => Inj p (Data.Semigroup.Last a) where
+  inj = pure . inj
+
+instance Inj p a => Inj p (Data.Semigroup.First a) where
+  inj = pure . inj
+
+instance Inj p a => Inj p (Max a) where
+  inj = pure . inj
+
+instance Inj p a => Inj p (Min a) where
+  inj = pure . inj
+
+instance
+    TypeError
+      ('Text "Refusing to decide whether to inject " ':<>:
+       'ShowType p ':<>: 'Text " into 'Left' " ':<>:
+       'ShowType x ':<>: 'Text " or 'Right' " ':<>: 'ShowType y ':$$:
+       'Text "in the " ':<>: 'ShowType Inj ':<>:
+       'Text " instance for " ':<>: 'ShowType Either) =>
+    Inj p (Either x y)
+  where
+    inj = error "impossible"
+
+instance
+    TypeError
+      ('Text "Refusing to decide whether to inject " ':<>:
+       'ShowType p ':<>: 'Text " into 'fst' " ':<>:
+       'ShowType x ':<>: 'Text " or 'snd' " ':<>: 'ShowType y ':$$:
+       'Text "in the " ':<>: 'ShowType Inj ':<>:
+       'Text " instance for " ':<>: 'ShowType (,)) =>
+    Inj p ((,) x y)
+  where
+    inj = error "impossible"
+
+instance Inj p a => Inj p (ST s a) where
+  inj = pure . inj
+
+instance Inj p a => Inj p (r -> a) where
+  inj = pure . inj
+
+instance Inj p (f (g a)) => Inj p (Compose f g a) where
+  inj = Compose . inj
+
+--------------------------------------------------------------------------------
+-- Generic
+--------------------------------------------------------------------------------
+
+instance Inj p (f a) => Inj p (Rec1 f a) where
+  inj = Rec1 . inj
+
+instance Inj p (f a) => Inj p (M1 i c f a) where
+  inj = M1 . inj
+
+instance Inj p a => Inj p (Par1 a) where
+  inj = Par1 . inj
+
+instance Inj p a => Inj p (K1 i a x) where
+  inj = K1 . inj
+
+instance Inj p (f (g a)) => Inj p ((:.:) f g a) where
+  inj = Comp1 . inj
diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,30 @@
+Copyright (c) 2018, Vladislav Zavialov
+
+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 Vladislav Zavialov 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/inj-base.cabal b/inj-base.cabal
new file mode 100644
--- /dev/null
+++ b/inj-base.cabal
@@ -0,0 +1,16 @@
+name:                inj-base
+version:             0.1.0.0
+synopsis:            'Inj' instances for 'base'
+license:             BSD3
+license-file:        LICENSE
+author:              Vladislav Zavialov
+maintainer:          Vladislav Zavialov <vlad.z.4096@gmail.com>
+category:            Data
+build-type:          Simple
+cabal-version:       >=1.10
+
+library
+  exposed-modules:     Inj.Base
+  build-depends:       base >=4.11 && <5, inj
+  default-language:    Haskell2010
+  ghc-options:         -Wall -fno-warn-orphans