Implement hash for NSDate and subclasses to return time interval since reference date (coerced to unsigned int).

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@19394 72102866-910b-0410-8b05-ffd578937521

ChangeLog

@@ -1,3 +1,8 @@
+2004-05-24 Richard Frith-Macdonald <rfm@gnu.org>
+
+	* Source/NSDate.m: Implement -hash for abstract class and for the
+	concrete subclasses as suggested by Marcus Muller.
+
 2004-05-21  Adam Fedor  <fedor@gnu.org>
 
 	* Tools/gdomap.c (xgethostnames): New function

Source/NSDate.m

@@ -1323,6 +1323,11 @@ GSTimeNow(void)
   return self;
 }
 
+- (unsigned) hash
+{
+  return (unsigned)[self timeIntervalSinceReferenceDate];
+}
+
 - (BOOL) isEqual: (id)other
 {
   if (other == nil)
@@ -1453,6 +1458,11 @@ GSTimeNow(void)
   return self;
 }
 
+- (unsigned) hash
+{
+  return (unsigned)_seconds_since_ref;
+}
+
 - (BOOL) isEqual: (id)other
 {
   if (other == nil)