1 files changed, 31 insertions, 0 deletions
diff --git a/testsuite/tests/dcoercion/DCo_Array.hs b/testsuite/tests/dcoercion/DCo_Array.hs
new file mode 100644
index 0000000000..cf3e389a09
--- /dev/null
+++ b/testsuite/tests/dcoercion/DCo_Array.hs
@@ -0,0 +1,31 @@
+{-# LANGUAGE
+    MagicHash
+  , UnboxedTuples
+  , UnliftedFFITypes
+ #-}
+
+module DCo_Array where
+
+import DCo_Array_aux
+  ( memcpy_thaw )
+
+import GHC.Exts
+  ( Ptr, Int(I#), RealWorld
+  , MutableByteArray#, ByteArray#
+  , newByteArray#
+  )
+import GHC.IO ( IO(..) )
+import GHC.ST ( ST(..) )
+
+data UArray e = UArray !Int ByteArray#
+data STUArray s e = STUArray !Int (MutableByteArray# s)
+
+thawSTUArray :: UArray e -> ST RealWorld (STUArray RealWorld e)
+thawSTUArray (UArray n@(I# n#) arr#) = ST $ \s1# ->
+  case newByteArray# n# s1# of
+    (# s2#, marr# #) ->
+      case memcpy_thaw marr# arr# (fromIntegral n) of
+        IO m ->
+          case m s2# of
+            (# s3#, _ #) ->
+              (# s3#, STUArray n marr# #)