[commit: packages/binary] master: Only support Void for >= GHC 7.10. (0adaed9)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/binary

On branch  : master
Link       : http://git.haskell.org/packages/binary.git/commitdiff/0adaed92127dde38d5fd9ad584b0e2215f0eb09a

>---------------------------------------------------------------

commit 0adaed92127dde38d5fd9ad584b0e2215f0eb09a
Author: Lennart Kolmodin <kolmodin at google.com>
Date:   Wed Nov 11 11:12:14 2015 +0100

    Only support Void for >= GHC 7.10.


>---------------------------------------------------------------

0adaed92127dde38d5fd9ad584b0e2215f0eb09a
 binary.cabal             | 4 ----
 src/Data/Binary/Class.hs | 5 +++++
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/binary.cabal b/binary.cabal
index 503e588..37ed51c 100644
--- a/binary.cabal
+++ b/binary.cabal
@@ -50,10 +50,6 @@ library
       -- prior to ghc-7.4 generics lived in ghc-prim
       build-depends: ghc-prim
 
-  if impl(ghc <= 7.8)
-    -- Data.Void was moved to base for 7.10
-    build-depends: void
-
   ghc-options:     -O2 -Wall -fliberate-case-threshold=1000
 
 -- Due to circular dependency, we cannot make any of the test-suites or
diff --git a/src/Data/Binary/Class.hs b/src/Data/Binary/Class.hs
index 9984a93..a022a42 100644
--- a/src/Data/Binary/Class.hs
+++ b/src/Data/Binary/Class.hs
@@ -8,6 +8,7 @@
 
 #if MIN_VERSION_base(4,8,0)
 #define HAS_NATURAL
+#define HAS_VOID
 #endif
 
 #if __GLASGOW_HASKELL__ >= 704
@@ -43,7 +44,9 @@ module Data.Binary.Class (
 import Data.Word
 import Data.Bits
 import Data.Int
+#ifdef HAS_VOID
 import Data.Void
+#endif
 
 import Data.Binary.Put
 import Data.Binary.Get
@@ -129,11 +132,13 @@ class Binary t where
 ------------------------------------------------------------------------
 -- Simple instances
 
+#ifdef HAS_VOID
 -- Void never gets written nor reconstructed since it's impossible to have a
 -- value of that type
 instance Binary Void where
     put     = absurd
     get     = mzero
+#endif
 
 -- The () type need never be written to disk: values of singleton type
 -- can be reconstructed from the type alone