Support GroupVarint.h under MSVC

Summary: MSVC supports the intrinsics used by it without any issue other changes, so just make sure the error doesn't trigger on MSVC.
Closes #252

Reviewed By: @yfeldblum

Differential Revision: D2282942

Pulled By: @sgolemon

diff --git a/folly/GroupVarint.h b/folly/GroupVarint.h
index f50617cb7c7003f2b3b666bf878c473a7cbaf560..153673ca16fa50699ff788e6a915b8e77cdc74f9 100644 (file)
--- a/folly/GroupVarint.h
+++ b/folly/GroupVarint.h
@@ -17,8 +17,8 @@
 #ifndef FOLLY_GROUPVARINT_H_
 #define FOLLY_GROUPVARINT_H_
 
-#ifndef __GNUC__
-#error GroupVarint.h requires GCC
+#if !defined(__GNUC__) && !defined(_MSC_VER)
+#error GroupVarint.h requires GCC or MSVC
 #endif
 
 #include <folly/Portability.h>