From: Ivan Maidanski <iv...@mail.ru>

2011-07-20  Ivan Maidanski  <iv...@mail.ru>

        * java/util/Collections.java:
        (emptySet(), EmptySet.iterator(), emptyList(), emptyMap(),
        EmptyMap.entrySet(), EmptyMap.keySet(), EmptyMap.values(),
        SingletonList.subList(int, int)): Suppress "unchecked" warnings.
        (emptySet(), emptyList(), emptyMap()): Don't create new instance (use
        the corresponding immutable container instance); remove FIXME.
        (EmptySet.equals(Object), EmptyList.equals(Object),
        EmptyMap.entrySet(), EmptyMap.equals(Object), EmptyMap.keySet(),
        EmptyMap.values(), SingletonList.subList(int, int)): Add generic
        typing.
        (SynchronizedCollection.toArray(T[])): Rename T type to E (to
        suppress compiler warning about type hiding).
---
 ChangeLog                  |   15 +++++++++++++++
 java/util/Collections.java |   33 +++++++++++++++++++--------------
 2 files changed, 34 insertions(+), 14 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index c0d84cd..5690754 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,20 @@
 2011-07-20  Ivan Maidanski  <iv...@mail.ru>
 
+       * java/util/Collections.java:
+       (emptySet(), EmptySet.iterator(), emptyList(), emptyMap(),
+       EmptyMap.entrySet(), EmptyMap.keySet(), EmptyMap.values(),
+       SingletonList.subList(int, int)): Suppress "unchecked" warnings.
+       (emptySet(), emptyList(), emptyMap()): Don't create new instance (use
+       the corresponding immutable container instance); remove FIXME.
+       (EmptySet.equals(Object), EmptyList.equals(Object),
+       EmptyMap.entrySet(), EmptyMap.equals(Object), EmptyMap.keySet(),
+       EmptyMap.values(), SingletonList.subList(int, int)): Add generic
+       typing.
+       (SynchronizedCollection.toArray(T[])): Rename T type to E (to
+       suppress compiler warning about type hiding).
+
+2011-07-20  Ivan Maidanski  <iv...@mail.ru>
+
        * native/jni/java-util/java_util_VMTimeZone.c:
        Include jcl.h file.
        (Java_java_util_VMTimeZone_getSystemTimeZoneId): Throw
diff --git a/java/util/Collections.java b/java/util/Collections.java
index 828c6ec..e7e7056 100644
--- a/java/util/Collections.java
+++ b/java/util/Collections.java
@@ -120,10 +120,10 @@ public class Collections
    * @return an empty parameterized set.
    * @since 1.5
    */
+  @SuppressWarnings("unchecked")
   public static final <T> Set<T> emptySet()
   {
-    /* FIXME: Could this be optimized? */
-    return new EmptySet<T>();
+    return (Set<T>) EMPTY_SET;
   }
 
   /**
@@ -161,6 +161,7 @@ public class Collections
      * @return A non-iterating iterator.
      */
     // This is really cheating! I think it's perfectly valid, though.
+    @SuppressWarnings("unchecked")
     public Iterator<T> iterator()
     {
       return (Iterator<T>) EMPTY_LIST.iterator();
@@ -196,7 +197,7 @@ public class Collections
      */
     public boolean equals(Object o)
     {
-      return o instanceof Set && ((Set) o).isEmpty();
+      return o instanceof Set<?> && ((Set<?>) o).isEmpty();
     }
 
     /**
@@ -288,10 +289,10 @@ public class Collections
    * @return an empty parameterized list.
    * @since 1.5
    */
+  @SuppressWarnings("unchecked")
   public static final <T> List<T> emptyList()
   {
-    /* FIXME: Could this be optimized? */
-    return new EmptyList<T>();
+    return (List<T>) EMPTY_LIST;
   }
 
   /**
@@ -369,7 +370,7 @@ public class Collections
      */
     public boolean equals(Object o)
     {
-      return o instanceof List && ((List) o).isEmpty();
+      return o instanceof List<?> && ((List<?>) o).isEmpty();
     }
 
     /**
@@ -480,10 +481,10 @@ public class Collections
    * @return an empty parameterized map.
    * @since 1.5
    */
+  @SuppressWarnings("unchecked")
   public static final <K,V> Map<K,V> emptyMap()
   {
-    /* FIXME: Could this be optimized? */
-    return new EmptyMap<K,V>();
+    return (Map<K,V>) EMPTY_MAP;
   }
 
   /**
@@ -511,9 +512,10 @@ public class Collections
      * There are no entries.
      * @return The empty set.
      */
+    @SuppressWarnings("unchecked")
     public Set<Map.Entry<K, V>> entrySet()
     {
-      return EMPTY_SET;
+      return (Set<Map.Entry<K, V>>) EMPTY_SET;
     }
 
     // The remaining methods are optional, but provide a performance
@@ -546,7 +548,7 @@ public class Collections
      */
     public boolean equals(Object o)
     {
-      return o instanceof Map && ((Map) o).isEmpty();
+      return o instanceof Map<?,?> && ((Map<?,?>) o).isEmpty();
     }
 
     /**
@@ -572,9 +574,10 @@ public class Collections
      * No entries.
      * @return The empty set.
      */
+    @SuppressWarnings("unchecked")
     public Set<K> keySet()
     {
-      return EMPTY_SET;
+      return (Set<K>) EMPTY_SET;
     }
 
     /**
@@ -601,9 +604,10 @@ public class Collections
      * Collection, will work. Besides, that's what the JDK uses!
      * @return The empty set.
      */
+    @SuppressWarnings("unchecked")
     public Collection<V> values()
     {
-      return EMPTY_SET;
+      return (Collection<V>) EMPTY_SET;
     }
 
     /**
@@ -1851,10 +1855,11 @@ public class Collections
      * @throws IndexOutOfBoundsException if either bound is greater
      *         than 1.
      */
+    @SuppressWarnings("unchecked")
     public List<T> subList(int from, int to)
     {
       if (from == to && (to == 0 || to == 1))
-        return EMPTY_LIST;
+        return (List<T>) EMPTY_LIST;
       if (from == 0 && to == 1)
         return this;
       if (from > to)
@@ -2480,7 +2485,7 @@ public class Collections
      * @throws ArrayStoreException if the type of any element of the
      *         collection is not a subtype of the element type of a.
      */
-    public <T> T[] toArray(T[] a)
+    public <E> E[] toArray(E[] a)
     {
       synchronized (mutex)
         {
-- 
1.7.7.6


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