fix warning

README.md

@@ -25,7 +25,7 @@ This repository aims to provide an set of excellent hash map implementations, wi
 
 - Automatic support for **boost's hash_value()** method for providing the hash function (see `examples/hash_value.h`).
 
-- **natvis** visualization support in Visual Studio
+- **natvis** visualization support in Visual Studio.
 
 
 ## Fast *and*  memory friendly

parallel_hashmap/phmap.h

@@ -325,7 +325,7 @@ struct GroupSse2Impl
         return BitMask<uint32_t, kWidth>(
             _mm_movemask_epi8(_mm_sign_epi8(ctrl, ctrl)));
 #else
-        return Match(kEmpty);
+        return Match(static_cast<h2_t>(kEmpty));
 #endif
     }