1 files changed, 64 insertions, 0 deletions
diff --git a/csharp/src/ProtocolBuffers/Descriptors/IndexedDescriptorBase.cs b/csharp/src/ProtocolBuffers/Descriptors/IndexedDescriptorBase.cs
new file mode 100644
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+++ b/csharp/src/ProtocolBuffers/Descriptors/IndexedDescriptorBase.cs
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+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://github.com/jskeet/dotnet-protobufs/
+// Original C++/Java/Python code:
+// http://code.google.com/p/protobuf/
+//
+// 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.
+using Google.ProtocolBuffers.DescriptorProtos;
+
+namespace Google.ProtocolBuffers.Descriptors
+{
+    /// <summary>
+    /// Base class for descriptors which are also indexed. This is all of them other than
+    /// <see cref="FileDescriptor" />.
+    /// </summary>
+    public abstract class IndexedDescriptorBase<TProto, TOptions> : DescriptorBase<TProto, TOptions>
+        where TProto : IMessage<TProto>, IDescriptorProto<TOptions>
+    {
+        private readonly int index;
+
+        protected IndexedDescriptorBase(TProto proto, FileDescriptor file, string fullName, int index)
+            : base(proto, file, fullName)
+        {
+            this.index = index;
+        }
+
+        /// <value>
+        /// The index of this descriptor within its parent descriptor. 
+        /// </value>
+        /// <remarks>
+        /// This returns the index of this descriptor within its parent, for
+        /// this descriptor's type. (There can be duplicate values for different
+        /// types, e.g. one enum type with index 0 and one message type with index 0.)
+        /// </remarks>
+        public int Index
+        {
+            get { return index; }
+        }
+    }
+}
+\ No newline at end of file