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Diffstat (limited to 'libraries/base/GHC/Arr.hs')
| -rw-r--r-- | libraries/base/GHC/Arr.hs | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/libraries/base/GHC/Arr.hs b/libraries/base/GHC/Arr.hs index e68c70f6bc..cefef97f0f 100644 --- a/libraries/base/GHC/Arr.hs +++ b/libraries/base/GHC/Arr.hs @@ -1,5 +1,5 @@ {-# LANGUAGE Unsafe #-} -{-# LANGUAGE NoImplicitPrelude, MagicHash, UnboxedTuples #-} +{-# LANGUAGE NoImplicitPrelude, MagicHash, UnboxedTuples, RoleAnnotations #-} {-# OPTIONS_HADDOCK hide #-} ----------------------------------------------------------------------------- @@ -385,6 +385,10 @@ data STArray s i e -- No Ix context for STArray. They are stupid, -- and force an Ix context on the equality instance. +-- Index types should have nominal role, because of Ix class. See also #9220. +type role Array nominal representational +type role STArray nominal nominal representational + -- Just pointer equality on mutable arrays: instance Eq (STArray s i e) where STArray _ _ _ arr1# == STArray _ _ _ arr2# = |