diff --git a/CHANGES.txt b/CHANGES.txt
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,42 +1,44 @@
 Changelog for Safe
 
-0.3.15
+0.3.16
+    #22, add Safe index
+0.3.15, released 2017-06-18
     Support QuickCheck 2.10
-0.3.14
+0.3.14, released 2017-02-15
     #20, fix for GHC 7.10.1
-0.3.13
+0.3.13, released 2017-02-09
     #20, require GHC 7.4 or above
-0.3.12
+0.3.12, released 2017-02-05
     #19, add Safe.Partial exposing a Partial typeclass
     #19, add support for GHC call stacks
-0.3.11
+0.3.11, released 2017-01-22
     #16, add Safe succ and pred
     #16, add readEitherSafe for better errors than readEither
     #14, add Safe zip3Exact
-0.3.10
+0.3.10, released 2016-11-08
     #15, add Safe cycle
-0.3.9
+0.3.9, released 2015-05-09
     #9, add Safe toEnum
-0.3.8
+0.3.8, released 2014-08-10
     #8, remove unnecessary Ord constraints from Foldable functions
-0.3.7
+0.3.7, released 2014-07-16
     Add Def variants of the Exact functions
-0.3.6
+0.3.6, released 2014-07-12
     #6, remove unnecessary Ord constraints from maximumBy/minimumBy
-0.3.5
+0.3.5, released 2014-06-28
     Add Safe elemIndexJust/findIndexJust functions
     Add Safe scan functions
     Add Safe minimumBy/maximumBy functions
     Add a module of Exact functions
     Add Foldable minimum functions
     Clean up the Foldable module, deprecate the Safe variants
-0.3.4
+0.3.4, released 2014-01-30
     #1, improve the string clipping in readNote
-0.3.3
+0.3.3, released 2011-11-15
     #494, add foldl1' wrappings
-0.3.2
+0.3.2, released 2011-11-13
     Add a Safe.Foldable module
-0.3.1
+0.3.1, released 2011-11-09
     Add findJust, safe wrapping of fromJust/find
-0.3
+0.3, released 2010-11-10
     Start of changelog
diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,4 +1,4 @@
-Copyright Neil Mitchell 2007-2017.
+Copyright Neil Mitchell 2007-2018.
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
diff --git a/Safe.hs b/Safe.hs
--- a/Safe.hs
+++ b/Safe.hs
@@ -49,9 +49,11 @@
     toEnumMay, toEnumDef, toEnumNote, toEnumSafe,
     succMay, succDef, succNote, succSafe,
     predMay, predDef, predNote, predSafe,
+    indexMay, indexDef, indexNote,
     ) where
 
 import Safe.Util
+import Data.Ix
 import Data.List
 import Data.Maybe
 import Safe.Partial
@@ -333,3 +335,12 @@
 
 predSafe :: (Enum a, Eq a, Bounded a) => a -> a
 predSafe = predDef minBound
+
+indexMay :: Ix a => (a, a) -> a -> Maybe Int
+indexMay b i = if inRange b i then Just (index b i) else Nothing
+
+indexDef :: Ix a => Int -> (a, a) -> a -> Int
+indexDef def b = fromMaybe def . indexMay b
+
+indexNote :: Ix a => String -> (a, a) -> a -> Int
+indexNote note b = fromNote note "indexNote, out of range" . indexMay b
diff --git a/Test.hs b/Test.hs
--- a/Test.hs
+++ b/Test.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE ScopedTypeVariables #-}
+{-# OPTIONS_GHC -fno-warn-orphans #-} -- In the test suite, so OK
 
 module Main(main) where
 
diff --git a/safe.cabal b/safe.cabal
--- a/safe.cabal
+++ b/safe.cabal
@@ -1,17 +1,17 @@
 cabal-version:  >= 1.18
 build-type:     Simple
 name:           safe
-version:        0.3.15
+version:        0.3.16
 license:        BSD3
 license-file:   LICENSE
 category:       Unclassified
 author:         Neil Mitchell <ndmitchell@gmail.com>
 maintainer:     Neil Mitchell <ndmitchell@gmail.com>
-copyright:      Neil Mitchell 2007-2017
+copyright:      Neil Mitchell 2007-2018
 homepage:       https://github.com/ndmitchell/safe#readme
 synopsis:       Library of safe (exception free) functions
 bug-reports:    https://github.com/ndmitchell/safe/issues
-tested-with:    GHC==8.0.2, GHC==7.10.3, GHC==7.8.4, GHC==7.6.3, GHC==7.4.2
+tested-with:    GHC==8.2.1, GHC==8.0.2, GHC==7.10.3, GHC==7.8.4, GHC==7.6.3, GHC==7.4.2
 description:
     A library wrapping @Prelude@/@Data.List@ functions that can throw exceptions, such as @head@ and @!!@.
     Each unsafe function has up to four variants, e.g. with @tail@:
@@ -60,6 +60,12 @@
     main-is:            Test.hs
     default-language:   Haskell2010
 
+    other-modules:
+        Safe
+        Safe.Exact
+        Safe.Foldable
+        Safe.Partial
+        Safe.Util
     build-depends:
         base,
         deepseq,