Support union return type for anonymous named/indexed getter

Source/wtf/UnionType.h

 /*
- * Copyright (C) 2012 Apple Inc. All rights reserved.
+ * Copyright (C) 2009, 2011 Apple Inc. All rights reserved.

[haraken, 2013/05/15 12:09:43]

Please use this:

/*
 * Copyright (C) 2013 Google Inc. All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef BitArray_h
-#define BitArray_h
-
-#include <string.h>
-#include <wtf/Assertions.h>
+#ifndef UnionType_h
+#define UnionType_h
 
 namespace WTF {
 
-template<unsigned arraySize>
-class BitArray {
+/*
+ * UnionTypeN holds multiple types of objects.

[haraken, 2013/05/15 12:09:43]

Nit: Blink uses // for multiline comments.

+ *
+ * WebIDL(UnionType):
+ * http://www.w3.org/TR/WebIDL/#prod-UnionType
+ *
+ * Example IDL:
+ * http://www.whatwg.org/specs/web-apps/current-work/multipage/common-dom-interfaces.html#htmlformcontrolscollection
+ */
+template<typename Type0, typename Type1>
+class UnionType2 {
 public:
-    BitArray()
+    explicit UnionType2()

[haraken, 2013/05/15 12:09:43]

'explicit' is needed only for one-argument constructor.

     {
-        memset(m_data, 0, sizeof(m_data));
     }
+    explicit UnionType2(PassRefPtr<Type0> value)
+    {
+        m_value0 = value;
+    }
+    explicit UnionType2(PassRefPtr<Type1> value)
+    {
+        m_value1 = value;
+    }
+    bool isNull() const
+    {
+        return !m_value0 && !m_value1;
+    }
+    PassRefPtr<Type0> enabledValue0() const

[jsbell, 2013/05/15 21:37:52]

Naming suggestion: in Web IDL, a UnionType is composed of UnionMemberTypes. And
humans start counting at 1. So perhaps member1(), member2() etc?

+    {
+        return m_value0;
+    }
+    PassRefPtr<Type1> enabledValue1() const
+    {
+        return m_value1;
+    }
+private:
+    RefPtr<Type0> m_value0;
+    RefPtr<Type1> m_value1;
+};
 
-    void set(unsigned index)
-    {
-        ASSERT_WITH_SECURITY_IMPLICATION(index < arraySize);
-        m_data[index / 8] |= 1 << (index & 7);
-    }
-
-    bool get(unsigned index) const
-    {
-        ASSERT_WITH_SECURITY_IMPLICATION(index < arraySize);
-        return !!(m_data[index / 8] & (1 << (index & 7)));
-    }
-
-private:
-    unsigned char m_data[arraySize / 8 + 1];
-};
 
 } // namespace WTF
 
-using WTF::BitArray;
-
-#endif // BitArray_h
+#endif // UnionType_h