JDK 10 [New Enhancement] - Consistently use primitive hashCode() variants in Arrays.hashCode() for primitive arrays

[Christoph Dreis]

Hey,

I just noticed that the Arrays.hashCode() variants for arrays of primitive
types could use the methods in Float, Boolean etc. instead of duplicating
the code. Please find the patch below.

What do you think? I'd be happy if this is picked up for JDK 10. 

Cheers,
Christoph

=========== PATCH ======================
diff --git a/src/java.base/share/classes/java/util/Arrays.java
b/src/java.base/share/classes/java/util/Arrays.java
--- a/src/java.base/share/classes/java/util/Arrays.java
+++ b/src/java.base/share/classes/java/util/Arrays.java
@@ -4456,8 +4456,7 @@

         int result = 1;
         for (long element : a) {
-            int elementHash = (int)(element ^ (element >>> 32));
-            result = 31 * result + elementHash;
+            result = 31 * result + Long.hashCode(element);
         }

         return result;
@@ -4593,7 +4592,7 @@

         int result = 1;
         for (boolean element : a)
-            result = 31 * result + (element ? 1231 : 1237);
+            result = 31 * result + Boolean.hashCode(element);

         return result;
     }
@@ -4620,7 +4619,7 @@

         int result = 1;
         for (float element : a)
-            result = 31 * result + Float.floatToIntBits(element);
+            result = 31 * result + Float.hashCode(element);

         return result;
     }
@@ -4647,8 +4646,7 @@

         int result = 1;
         for (double element : a) {
-            long bits = Double.doubleToLongBits(element);
-            result = 31 * result + (int)(bits ^ (bits >>> 32));
+            result = 31 * result + Double.hashCode(element);
         }
         return result;
     }