Creating a branch for experimenting with some ideas for JMS client.rajith_jms_client

git-svn-id: https://svn.apache.org/repos/asf/qpid/branches/rajith_jms_client@1128369 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 71 insertions, 0 deletions

diff --git a/qpid/cpp/include/qpid/messaging/Handle.h b/qpid/cpp/include/qpid/messaging/Handle.h
new file mode 100644
index 0000000000..97a8f00b54
--- /dev/null
+++ b/qpid/cpp/include/qpid/messaging/Handle.h
@@ -0,0 +1,71 @@
+#ifndef QPID_MESSAGING_HANDLE_H
+#define QPID_MESSAGING_HANDLE_H
+
+/*
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ *
+ */
+
+#include "qpid/messaging/ImportExport.h"
+
+namespace qpid {
+namespace messaging {
+
+template <class> class PrivateImplRef;
+
+/** \ingroup messaging 
+ * A handle is like a pointer: refers to an underlying implementation object.
+ * Copying the handle does not copy the object.
+ *
+ * Handles can be null,  like a 0 pointer. Use isValid(), isNull() or the
+ * conversion to bool to test for a null handle.
+ */
+template <class T> class Handle {
+  public:
+
+    /**@return true if handle is valid,  i.e. not null. */
+    QPID_MESSAGING_INLINE_EXTERN bool isValid() const { return impl; }
+
+    /**@return true if handle is null. It is an error to call any function on a null handle. */
+    QPID_MESSAGING_INLINE_EXTERN bool isNull() const { return !impl; }
+
+    /** Conversion to bool supports idiom if (handle) { handle->... } */
+    QPID_MESSAGING_INLINE_EXTERN operator bool() const { return impl; }
+
+    /** Operator ! supports idiom if (!handle) { do_if_handle_is_null(); } */
+    QPID_MESSAGING_INLINE_EXTERN bool operator !() const { return !impl; }
+
+    void swap(Handle<T>& h) { T* t = h.impl; h.impl = impl; impl = t; }
+
+  protected:
+    typedef T Impl;
+    QPID_MESSAGING_INLINE_EXTERN Handle() :impl() {}
+
+    // Not implemented,subclasses must implement.
+    QPID_MESSAGING_EXTERN Handle(const Handle&);
+    QPID_MESSAGING_EXTERN Handle& operator=(const Handle&);
+
+    Impl* impl;
+
+  friend class PrivateImplRef<T>;
+};
+
+}} // namespace qpid::messaging
+
+#endif  /*!QPID_MESSAGING_HANDLE_H*/