Use delegates instead of dynamic reflection.

csharp/ProtocolBuffers.Test/TestProtos/MessageWithNoOuter.cs

@@ -16,11 +16,15 @@ namespace Google.ProtocolBuffers.TestProtos {
       get { return defaultInstance; }
     }
     
+    protected override MessageWithNoOuter ThisMessage {
+      get { return this; }
+    }
+    
     public static pbd::MessageDescriptor Descriptor {
       get { return global::Google.ProtocolBuffers.TestProtos.MultiFileProto.internal__static_protobuf_unittest_MessageWithNoOuter__Descriptor; }
     }
     
-    protected override pb::FieldAccess.FieldAccessorTable InternalFieldAccessors {
+    protected override pb::FieldAccess.FieldAccessorTable<MessageWithNoOuter, MessageWithNoOuter.Builder> InternalFieldAccessors {
       get { return global::Google.ProtocolBuffers.TestProtos.MultiFileProto.internal__static_protobuf_unittest_MessageWithNoOuter__FieldAccessorTable; }
     }
     
@@ -40,11 +44,15 @@ namespace Google.ProtocolBuffers.TestProtos {
           get { return defaultInstance; }
         }
         
+        protected override NestedMessage ThisMessage {
+          get { return this; }
+        }
+        
         public static pbd::MessageDescriptor Descriptor {
           get { return global::Google.ProtocolBuffers.TestProtos.MultiFileProto.internal__static_protobuf_unittest_MessageWithNoOuter_NestedMessage__Descriptor; }
         }
         
-        protected override pb::FieldAccess.FieldAccessorTable InternalFieldAccessors {
+        protected override pb::FieldAccess.FieldAccessorTable<NestedMessage, NestedMessage.Builder> InternalFieldAccessors {
           get { return global::Google.ProtocolBuffers.TestProtos.MultiFileProto.internal__static_protobuf_unittest_MessageWithNoOuter_NestedMessage__FieldAccessorTable; }
         }
         

csharp/ProtocolBuffers.Test/TestProtos/MultiFileProto.cs

@@ -64,18 +64,14 @@ namespace Google.ProtocolBuffers.TestProtos {
     #region Static variables
     internal static readonly pbd::MessageDescriptor internal__static_protobuf_unittest_MessageWithNoOuter__Descriptor 
         = Descriptor.MessageTypes[0];
-    internal static pb::FieldAccess.FieldAccessorTable internal__static_protobuf_unittest_MessageWithNoOuter__FieldAccessorTable
-        = new pb::FieldAccess.FieldAccessorTable(internal__static_protobuf_unittest_MessageWithNoOuter__Descriptor,
-            new string[] { "Nested", "Foreign", "NestedEnum", "ForeignEnum", },
-            typeof (global::Google.ProtocolBuffers.TestProtos.MessageWithNoOuter),
-            typeof (global::Google.ProtocolBuffers.TestProtos.MessageWithNoOuter.Builder));
+    internal static pb::FieldAccess.FieldAccessorTable<global::Google.ProtocolBuffers.TestProtos.MessageWithNoOuter, global::Google.ProtocolBuffers.TestProtos.MessageWithNoOuter.Builder> internal__static_protobuf_unittest_MessageWithNoOuter__FieldAccessorTable
+        = new pb::FieldAccess.FieldAccessorTable<global::Google.ProtocolBuffers.TestProtos.MessageWithNoOuter, global::Google.ProtocolBuffers.TestProtos.MessageWithNoOuter.Builder>(internal__static_protobuf_unittest_MessageWithNoOuter__Descriptor,
+            new string[] { "Nested", "Foreign", "NestedEnum", "ForeignEnum", });
     internal static readonly pbd::MessageDescriptor  internal__static_protobuf_unittest_MessageWithNoOuter_NestedMessage__Descriptor 
         = internal__static_protobuf_unittest_MessageWithNoOuter__Descriptor.NestedTypes[0];
-    internal static pb::FieldAccess.FieldAccessorTable internal__static_protobuf_unittest_MessageWithNoOuter_NestedMessage__FieldAccessorTable
-        = new pb::FieldAccess.FieldAccessorTable(internal__static_protobuf_unittest_MessageWithNoOuter_NestedMessage__Descriptor,
-            new string[] { "I", },
-            typeof (global::Google.ProtocolBuffers.TestProtos.MessageWithNoOuter.Types.NestedMessage),
-            typeof (global::Google.ProtocolBuffers.TestProtos.MessageWithNoOuter.Types.NestedMessage.Builder));
+    internal static pb::FieldAccess.FieldAccessorTable<global::Google.ProtocolBuffers.TestProtos.MessageWithNoOuter.Types.NestedMessage, global::Google.ProtocolBuffers.TestProtos.MessageWithNoOuter.Types.NestedMessage.Builder> internal__static_protobuf_unittest_MessageWithNoOuter_NestedMessage__FieldAccessorTable
+        = new pb::FieldAccess.FieldAccessorTable<global::Google.ProtocolBuffers.TestProtos.MessageWithNoOuter.Types.NestedMessage, global::Google.ProtocolBuffers.TestProtos.MessageWithNoOuter.Types.NestedMessage.Builder>(internal__static_protobuf_unittest_MessageWithNoOuter_NestedMessage__Descriptor,
+            new string[] { "I", });
     #endregion
     
   }

csharp/ProtocolBuffers.Test/TestProtos/UnitTestEmbedOptimizeForProtoFile.cs

@@ -43,11 +43,9 @@ namespace Google.ProtocolBuffers.TestProtos {
     #region Static variables
     internal static readonly pbd::MessageDescriptor internal__static_protobuf_unittest_TestEmbedOptimizedForSize__Descriptor 
         = Descriptor.MessageTypes[0];
-    internal static pb::FieldAccess.FieldAccessorTable internal__static_protobuf_unittest_TestEmbedOptimizedForSize__FieldAccessorTable
-        = new pb::FieldAccess.FieldAccessorTable(internal__static_protobuf_unittest_TestEmbedOptimizedForSize__Descriptor,
-            new string[] { "OptionalMessage", "RepeatedMessage", },
-            typeof (global::Google.ProtocolBuffers.TestProtos.TestEmbedOptimizedForSize),
-            typeof (global::Google.ProtocolBuffers.TestProtos.TestEmbedOptimizedForSize.Builder));
+    internal static pb::FieldAccess.FieldAccessorTable<global::Google.ProtocolBuffers.TestProtos.TestEmbedOptimizedForSize, global::Google.ProtocolBuffers.TestProtos.TestEmbedOptimizedForSize.Builder> internal__static_protobuf_unittest_TestEmbedOptimizedForSize__FieldAccessorTable
+        = new pb::FieldAccess.FieldAccessorTable<global::Google.ProtocolBuffers.TestProtos.TestEmbedOptimizedForSize, global::Google.ProtocolBuffers.TestProtos.TestEmbedOptimizedForSize.Builder>(internal__static_protobuf_unittest_TestEmbedOptimizedForSize__Descriptor,
+            new string[] { "OptionalMessage", "RepeatedMessage", });
     #endregion
     
   }
@@ -66,11 +64,15 @@ namespace Google.ProtocolBuffers.TestProtos {
       get { return defaultInstance; }
     }
     
+    protected override TestEmbedOptimizedForSize ThisMessage {
+      get { return this; }
+    }
+    
     public static pbd::MessageDescriptor Descriptor {
       get { return global::Google.ProtocolBuffers.TestProtos.UnitTestEmbedOptimizeForProtoFile.internal__static_protobuf_unittest_TestEmbedOptimizedForSize__Descriptor; }
     }
     
-    protected override pb::FieldAccess.FieldAccessorTable InternalFieldAccessors {
+    protected override pb::FieldAccess.FieldAccessorTable<TestEmbedOptimizedForSize, TestEmbedOptimizedForSize.Builder> InternalFieldAccessors {
       get { return global::Google.ProtocolBuffers.TestProtos.UnitTestEmbedOptimizeForProtoFile.internal__static_protobuf_unittest_TestEmbedOptimizedForSize__FieldAccessorTable; }
     }
     

csharp/ProtocolBuffers.Test/TestProtos/UnitTestImportProtoFile.cs

@@ -37,11 +37,9 @@ namespace Google.ProtocolBuffers.TestProtos {
     #region Static variables
     internal static readonly pbd::MessageDescriptor internal__static_protobuf_unittest_import_ImportMessage__Descriptor 
         = Descriptor.MessageTypes[0];
-    internal static pb::FieldAccess.FieldAccessorTable internal__static_protobuf_unittest_import_ImportMessage__FieldAccessorTable
-        = new pb::FieldAccess.FieldAccessorTable(internal__static_protobuf_unittest_import_ImportMessage__Descriptor,
-            new string[] { "D", },
-            typeof (global::Google.ProtocolBuffers.TestProtos.ImportMessage),
-            typeof (global::Google.ProtocolBuffers.TestProtos.ImportMessage.Builder));
+    internal static pb::FieldAccess.FieldAccessorTable<global::Google.ProtocolBuffers.TestProtos.ImportMessage, global::Google.ProtocolBuffers.TestProtos.ImportMessage.Builder> internal__static_protobuf_unittest_import_ImportMessage__FieldAccessorTable
+        = new pb::FieldAccess.FieldAccessorTable<global::Google.ProtocolBuffers.TestProtos.ImportMessage, global::Google.ProtocolBuffers.TestProtos.ImportMessage.Builder>(internal__static_protobuf_unittest_import_ImportMessage__Descriptor,
+            new string[] { "D", });
     #endregion
     
   }
@@ -66,11 +64,15 @@ namespace Google.ProtocolBuffers.TestProtos {
       get { return defaultInstance; }
     }
     
+    protected override ImportMessage ThisMessage {
+      get { return this; }
+    }
+    
     public static pbd::MessageDescriptor Descriptor {
       get { return global::Google.ProtocolBuffers.TestProtos.UnitTestImportProtoFile.internal__static_protobuf_unittest_import_ImportMessage__Descriptor; }
     }
     
-    protected override pb::FieldAccess.FieldAccessorTable InternalFieldAccessors {
+    protected override pb::FieldAccess.FieldAccessorTable<ImportMessage, ImportMessage.Builder> InternalFieldAccessors {
       get { return global::Google.ProtocolBuffers.TestProtos.UnitTestImportProtoFile.internal__static_protobuf_unittest_import_ImportMessage__FieldAccessorTable; }
     }
     

csharp/ProtocolBuffers.Test/TestProtos/UnitTestOptimizeForProtoFile.cs

@@ -42,11 +42,9 @@ namespace Google.ProtocolBuffers.TestProtos {
     #region Static variables
     internal static readonly pbd::MessageDescriptor internal__static_protobuf_unittest_TestOptimizedForSize__Descriptor 
         = Descriptor.MessageTypes[0];
-    internal static pb::FieldAccess.FieldAccessorTable internal__static_protobuf_unittest_TestOptimizedForSize__FieldAccessorTable
-        = new pb::FieldAccess.FieldAccessorTable(internal__static_protobuf_unittest_TestOptimizedForSize__Descriptor,
-            new string[] { "I", "Msg", },
-            typeof (global::Google.ProtocolBuffers.TestProtos.TestOptimizedForSize),
-            typeof (global::Google.ProtocolBuffers.TestProtos.TestOptimizedForSize.Builder));
+    internal static pb::FieldAccess.FieldAccessorTable<global::Google.ProtocolBuffers.TestProtos.TestOptimizedForSize, global::Google.ProtocolBuffers.TestProtos.TestOptimizedForSize.Builder> internal__static_protobuf_unittest_TestOptimizedForSize__FieldAccessorTable
+        = new pb::FieldAccess.FieldAccessorTable<global::Google.ProtocolBuffers.TestProtos.TestOptimizedForSize, global::Google.ProtocolBuffers.TestProtos.TestOptimizedForSize.Builder>(internal__static_protobuf_unittest_TestOptimizedForSize__Descriptor,
+            new string[] { "I", "Msg", });
     #endregion
     
   }
@@ -65,11 +63,15 @@ namespace Google.ProtocolBuffers.TestProtos {
       get { return defaultInstance; }
     }
     
+    protected override TestOptimizedForSize ThisMessage {
+      get { return this; }
+    }
+    
     public static pbd::MessageDescriptor Descriptor {
       get { return global::Google.ProtocolBuffers.TestProtos.UnitTestOptimizeForProtoFile.internal__static_protobuf_unittest_TestOptimizedForSize__Descriptor; }
     }
     
-    protected override pb::FieldAccess.FieldAccessorTable InternalFieldAccessors {
+    protected override pb::FieldAccess.FieldAccessorTable<TestOptimizedForSize, TestOptimizedForSize.Builder> InternalFieldAccessors {
       get { return global::Google.ProtocolBuffers.TestProtos.UnitTestOptimizeForProtoFile.internal__static_protobuf_unittest_TestOptimizedForSize__FieldAccessorTable; }
     }
     

csharp/ProtocolBuffers/FieldAccess/Delegates.cs

+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Google.ProtocolBuffers.FieldAccess {
+
+  delegate bool HasDelegate<T>(T message);
+  delegate T ClearDelegate<T>(T builder);
+  delegate int RepeatedCountDelegate<T>(T message);
+  delegate object GetValueDelegate<T>(T message);
+}

csharp/ProtocolBuffers/FieldAccess/FieldAccessorTable.cs

@@ -23,9 +23,11 @@ namespace Google.ProtocolBuffers.FieldAccess {
   /// create appropriate instances in the .proto file description class.
   /// TODO(jonskeet): See if we can hide it somewhere...
   /// </summary>
-  public sealed class FieldAccessorTable {
+  public sealed class FieldAccessorTable<TMessage, TBuilder>
+      where TMessage : IMessage<TMessage, TBuilder>
+      where TBuilder : IBuilder<TMessage, TBuilder> {
 
-    readonly IFieldAccessor[] accessors;
+    readonly IFieldAccessor<TMessage, TBuilder>[] accessors;
 
     readonly MessageDescriptor descriptor;
 
@@ -39,36 +41,34 @@ namespace Google.ProtocolBuffers.FieldAccess {
     /// </summary>
     /// <param name="descriptor">The type's descriptor</param>
     /// <param name="propertyNames">The Pascal-case names of all the field-based properties in the message.</param>
-    /// <param name="messageType">The .NET type representing the message</param>
-    /// <param name="builderType">The .NET type representing the message's builder type</param>
-    public FieldAccessorTable(MessageDescriptor descriptor, String[] propertyNames, Type messageType, Type builderType) {
+    public FieldAccessorTable(MessageDescriptor descriptor, String[] propertyNames) {
       this.descriptor = descriptor;
-      accessors = new IFieldAccessor[descriptor.Fields.Count];
+      accessors = new IFieldAccessor<TMessage, TBuilder>[descriptor.Fields.Count];
       for (int i=0; i < accessors.Length; i++) {
-        accessors[i] = CreateAccessor(descriptor.Fields[i], propertyNames[i], messageType, builderType);
+        accessors[i] = CreateAccessor(descriptor.Fields[i], propertyNames[i]);
       }
     }
 
      /// <summary>
      /// Creates an accessor for a single field
      /// </summary>   
-    private static IFieldAccessor CreateAccessor(FieldDescriptor field, string name, Type messageType, Type builderType) {
+    private static IFieldAccessor<TMessage, TBuilder> CreateAccessor(FieldDescriptor field, string name) {
       if (field.IsRepeated) {
         switch (field.MappedType) {
-          case MappedType.Message: return new RepeatedMessageAccessor(name, messageType, builderType);
-          case MappedType.Enum: return new RepeatedEnumAccessor(field, name, messageType, builderType);
-          default: return new RepeatedPrimitiveAccessor(name, messageType, builderType);
+          case MappedType.Message: return new RepeatedMessageAccessor<TMessage, TBuilder>(name);
+          case MappedType.Enum: return new RepeatedEnumAccessor<TMessage, TBuilder>(field, name);
+          default: return new RepeatedPrimitiveAccessor<TMessage, TBuilder>(name);
         }
       } else {
         switch (field.MappedType) {
-          case MappedType.Message: return new SingleMessageAccessor(name, messageType, builderType);
-          case MappedType.Enum: return new SingleEnumAccessor(field, name, messageType, builderType);
-          default: return new SinglePrimitiveAccessor(name, messageType, builderType);
+          case MappedType.Message: return new SingleMessageAccessor<TMessage, TBuilder>(name);
+          case MappedType.Enum: return new SingleEnumAccessor<TMessage, TBuilder>(field, name);
+          default: return new SinglePrimitiveAccessor<TMessage, TBuilder>(name);
         }
       }
     }
 
-    internal IFieldAccessor this[FieldDescriptor field] {
+    internal IFieldAccessor<TMessage, TBuilder> this[FieldDescriptor field] {
       get {
         if (field.ContainingType != descriptor) {
           throw new ArgumentException("FieldDescriptor does not match message type.");

csharp/ProtocolBuffers/FieldAccess/IFieldAccessor.cs

@@ -21,23 +21,25 @@ namespace Google.ProtocolBuffers.FieldAccess {
   /// The property descriptors for each field are created once and then cached.
   /// In addition, this interface holds knowledge of repeated fields, builders etc.
   /// </summary>
-  internal interface IFieldAccessor {
+  internal interface IFieldAccessor<TMessage, TBuilder>
+      where TMessage : IMessage<TMessage, TBuilder>
+      where TBuilder : IBuilder<TMessage, TBuilder> {
 
     /// <summary>
     /// Indicates whether the specified message contains the field.
     /// </summary>
-    bool Has(IMessage message);
+    bool Has(TMessage message);
 
     /// <summary>
     /// Gets the count of the repeated field in the specified message.
     /// </summary>
-    int GetRepeatedCount(IMessage message);
+    int GetRepeatedCount(TMessage message);
 
     /// <summary>
     /// Clears the field in the specified builder.
     /// </summary>
     /// <param name="builder"></param>
-    void Clear(IBuilder builder);
+    void Clear(TBuilder builder);
 
     /// <summary>
     /// Creates a builder for the type of this field (which must be a message field).
@@ -47,11 +49,11 @@ namespace Google.ProtocolBuffers.FieldAccess {
     /// <summary>
     /// Accessor for single fields
     /// </summary>
-    object GetValue(IMessage message);
+    object GetValue(TMessage message);
     /// <summary>
     /// Mutator for single fields
     /// </summary>
-    void SetValue(IBuilder builder, object value);
+    void SetValue(TBuilder builder, object value);
 
     /// <summary>
     /// Accessor for repeated fields

csharp/ProtocolBuffers/FieldAccess/RepeatedEnumAccessor.cs

@@ -24,17 +24,17 @@ namespace Google.ProtocolBuffers.FieldAccess {
   /// <summary>
   /// Accessor for a repeated enum field.
   /// </summary>
-  internal sealed class RepeatedEnumAccessor : RepeatedPrimitiveAccessor {
+  internal sealed class RepeatedEnumAccessor<TMessage, TBuilder> : RepeatedPrimitiveAccessor<TMessage, TBuilder>
+      where TMessage : IMessage<TMessage, TBuilder>
+      where TBuilder : IBuilder<TMessage, TBuilder> {
 
     private readonly EnumDescriptor enumDescriptor;
 
-    internal RepeatedEnumAccessor(FieldDescriptor field, string name, Type messageType, Type builderType)
-        : base(name, messageType, builderType) {
-
+    internal RepeatedEnumAccessor(FieldDescriptor field, string name) : base(name) {
       enumDescriptor = field.EnumType;
     }
 
-    public override object GetValue(IMessage message) {
+    public override object GetValue(TMessage message) {
       List<EnumValueDescriptor> ret = new List<EnumValueDescriptor>();
       foreach (int rawValue in (IEnumerable) base.GetValue(message)) {
         ret.Add(enumDescriptor.FindValueByNumber(rawValue));

csharp/ProtocolBuffers/FieldAccess/RepeatedMessageAccessor.cs

@@ -24,7 +24,9 @@ namespace Google.ProtocolBuffers.FieldAccess {
   /// TODO(jonskeet): Try to extract the commonality between this and SingleMessageAccessor.
   /// We almost want multiple inheritance...
   /// </summary>
-  internal sealed class RepeatedMessageAccessor : RepeatedPrimitiveAccessor {
+  internal sealed class RepeatedMessageAccessor<TMessage, TBuilder> : RepeatedPrimitiveAccessor<TMessage, TBuilder>
+      where TMessage : IMessage<TMessage, TBuilder>
+      where TBuilder : IBuilder<TMessage, TBuilder> {
 
     /// <summary>
     /// The static method to create a builder for the property type. For example,
@@ -33,8 +35,7 @@ namespace Google.ProtocolBuffers.FieldAccess {
     /// </summary>
     private readonly MethodInfo createBuilderMethod;
 
-    internal RepeatedMessageAccessor(string name, Type messageType, Type builderType)
-        : base(name, messageType, builderType) {
+    internal RepeatedMessageAccessor(string name) : base(name) {
       createBuilderMethod = ClrType.GetMethod("CreateBuilder", new Type[0]);
       if (createBuilderMethod == null) {
         throw new ArgumentException("No public static CreateBuilder method declared in " + ClrType.Name);

csharp/ProtocolBuffers/FieldAccess/RepeatedPrimitiveAccessor.cs

@@ -21,12 +21,14 @@ namespace Google.ProtocolBuffers.FieldAccess {
   /// <summary>
   /// Accesor for a repeated field of type int, ByteString etc.
   /// </summary>
-  internal class RepeatedPrimitiveAccessor : IFieldAccessor {
+  internal class RepeatedPrimitiveAccessor<TMessage, TBuilder> : IFieldAccessor<TMessage, TBuilder>
+      where TMessage : IMessage<TMessage, TBuilder>
+      where TBuilder : IBuilder<TMessage, TBuilder> {
 
     private readonly PropertyInfo messageProperty;
     private readonly PropertyInfo builderProperty;
-    private readonly PropertyInfo countProperty;
-    private readonly MethodInfo clearMethod;
+    private readonly RepeatedCountDelegate<TMessage> countDelegate;
+    private readonly ClearDelegate<TBuilder> clearDelegate;
     private readonly MethodInfo addMethod;
     private readonly MethodInfo getElementMethod;
     private readonly MethodInfo setElementMethod;
@@ -40,14 +42,14 @@ namespace Google.ProtocolBuffers.FieldAccess {
       get { return getElementMethod.ReturnType; }
     }
 
-    internal RepeatedPrimitiveAccessor(string name, Type messageType, Type builderType) {      
-      messageProperty = messageType.GetProperty(name + "List");
-      builderProperty = builderType.GetProperty(name + "List");
-      countProperty = messageType.GetProperty(name + "Count");
-      clearMethod = builderType.GetMethod("Clear" + name);
-      getElementMethod = messageType.GetMethod("Get" + name, new Type[] { typeof(int) });
-      addMethod = builderType.GetMethod("Add" + name, new Type[] { ClrType });
-      setElementMethod = builderType.GetMethod("Set" + name, new Type[] { typeof(int), ClrType });
+    internal RepeatedPrimitiveAccessor(string name) {      
+      messageProperty = typeof(TMessage).GetProperty(name + "List");
+      builderProperty = typeof(TBuilder).GetProperty(name + "List");
+      PropertyInfo countProperty = typeof(TMessage).GetProperty(name + "Count");
+      MethodInfo clearMethod = typeof(TBuilder).GetMethod("Clear" + name);
+      getElementMethod = typeof(TMessage).GetMethod("Get" + name, new Type[] { typeof(int) });
+      addMethod = typeof(TBuilder).GetMethod("Add" + name, new Type[] { ClrType });
+      setElementMethod = typeof(TBuilder).GetMethod("Set" + name, new Type[] { typeof(int), ClrType });
       if (messageProperty == null 
           || builderProperty == null 
           || countProperty == null
@@ -57,9 +59,12 @@ namespace Google.ProtocolBuffers.FieldAccess {
           || setElementMethod == null) {
         throw new ArgumentException("Not all required properties/methods available");
       }
+      clearDelegate = (ClearDelegate<TBuilder>)Delegate.CreateDelegate(typeof(ClearDelegate<TBuilder>), clearMethod);
+      countDelegate = (RepeatedCountDelegate<TMessage>)Delegate.CreateDelegate
+          (typeof(RepeatedCountDelegate<TMessage>), countProperty.GetGetMethod());
     }
 
-    public bool Has(IMessage message) {
+    public bool Has(TMessage message) {
       throw new InvalidOperationException();
     }
     
@@ -67,11 +72,11 @@ namespace Google.ProtocolBuffers.FieldAccess {
       throw new InvalidOperationException();
     }
 
-    public virtual object GetValue(IMessage message) {
+    public virtual object GetValue(TMessage message) {
       return messageProperty.GetValue(message, null);
     }
 
-    public void SetValue(IBuilder builder, object value) {
+    public void SetValue(TBuilder builder, object value) {
       // Add all the elements individually.  This serves two purposes:
       // 1) Verifies that each element has the correct type.
       // 2) Insures that the caller cannot modify the list later on and
@@ -82,12 +87,12 @@ namespace Google.ProtocolBuffers.FieldAccess {
       }
     }
 
-    public void Clear(IBuilder builder) {
-      clearMethod.Invoke(builder, null);
+    public void Clear(TBuilder builder) {
+      clearDelegate(builder);
     }
 
-    public int GetRepeatedCount(IMessage message) {
-      return (int) countProperty.GetValue(message, null);
+    public int GetRepeatedCount(TMessage message) {
+      return countDelegate(message);
     }
 
     public virtual object GetRepeatedValue(IMessage message, int index) {

csharp/ProtocolBuffers/FieldAccess/SingleEnumAccessor.cs

@@ -20,12 +20,13 @@ namespace Google.ProtocolBuffers.FieldAccess {
   /// <summary>
   /// Accessor for fields representing a non-repeated enum value.
   /// </summary>
-  internal sealed class SingleEnumAccessor : SinglePrimitiveAccessor {
+  internal sealed class SingleEnumAccessor<TMessage, TBuilder> : SinglePrimitiveAccessor<TMessage, TBuilder>
+      where TMessage : IMessage<TMessage, TBuilder>
+      where TBuilder : IBuilder<TMessage, TBuilder> {
 
     private readonly EnumDescriptor enumDescriptor;
 
-    internal SingleEnumAccessor(FieldDescriptor field, string name, Type messageType, Type builderType) 
-        : base(name, messageType, builderType) {
+    internal SingleEnumAccessor(FieldDescriptor field, string name) : base(name) {
       enumDescriptor = field.EnumType;
     }
 
@@ -34,7 +35,7 @@ namespace Google.ProtocolBuffers.FieldAccess {
     /// Note that if an enum has multiple values for the same number, the descriptor
     /// for the first value with that number will be returned.
     /// </summary>
-    public override object GetValue(IMessage message) {
+    public override object GetValue(TMessage message) {
       // Note: This relies on the fact that the CLR allows unboxing from an enum to
       // its underlying value
       int rawValue = (int) base.GetValue(message);
@@ -45,7 +46,7 @@ namespace Google.ProtocolBuffers.FieldAccess {
     /// Sets the value as an enum (via an int) in the builder,
     /// from an EnumValueDescriptor parameter.
     /// </summary>
-    public override void SetValue(IBuilder builder, object value) {
+    public override void SetValue(TBuilder builder, object value) {
       EnumValueDescriptor valueDescriptor = (EnumValueDescriptor) value;
       base.SetValue(builder, valueDescriptor.Number);
     }

csharp/ProtocolBuffers/FieldAccess/SingleMessageAccessor.cs

@@ -20,7 +20,9 @@ namespace Google.ProtocolBuffers.FieldAccess {
   /// <summary>
   /// Accessor for fields representing a non-repeated message value.
   /// </summary>
-  internal sealed class SingleMessageAccessor : SinglePrimitiveAccessor {
+  internal sealed class SingleMessageAccessor<TMessage, TBuilder> : SinglePrimitiveAccessor<TMessage, TBuilder>
+      where TMessage : IMessage<TMessage, TBuilder>
+      where TBuilder : IBuilder<TMessage, TBuilder> {
 
     /// <summary>
     /// The static method to create a builder for the property type. For example,
@@ -30,8 +32,7 @@ namespace Google.ProtocolBuffers.FieldAccess {
     private readonly MethodInfo createBuilderMethod;
 
 
-    internal SingleMessageAccessor(string name, Type messageType, Type builderType) 
-        : base(name, messageType, builderType) {
+    internal SingleMessageAccessor(string name) : base(name) {
       
       createBuilderMethod = ClrType.GetMethod("CreateBuilder", new Type[0]);//BindingFlags.Public | BindingFlags.Static | BindingFlags.DeclaredOnly);
       if (createBuilderMethod == null) {
@@ -55,7 +56,7 @@ namespace Google.ProtocolBuffers.FieldAccess {
       return CreateBuilder().WeakMergeFrom(message).WeakBuild();
     }
 
-    public override void SetValue(IBuilder builder, object value) {
+    public override void SetValue(TBuilder builder, object value) {
       base.SetValue(builder, CoerceType(value));
     }
 

csharp/ProtocolBuffers/FieldAccess/SinglePrimitiveAccessor.cs

@@ -20,12 +20,14 @@ namespace Google.ProtocolBuffers.FieldAccess {
   /// <summary>
   /// Access for a non-repeated field of a "primitive" type (i.e. not another message or an enum).
   /// </summary>
-  internal class SinglePrimitiveAccessor : IFieldAccessor {
+  internal class SinglePrimitiveAccessor<TMessage, TBuilder> : IFieldAccessor<TMessage, TBuilder>
+      where TMessage : IMessage<TMessage, TBuilder>
+      where TBuilder : IBuilder<TMessage, TBuilder> {
 
     private readonly PropertyInfo messageProperty;
     private readonly PropertyInfo builderProperty;
-    private readonly PropertyInfo hasProperty;
-    private readonly MethodInfo clearMethod;
+    private readonly HasDelegate<TMessage> hasDelegate;
+    private readonly ClearDelegate<TBuilder> clearDelegate;
 
     /// <summary>
     /// The CLR type of the field (int, the enum type, ByteString, the message etc).
@@ -35,22 +37,24 @@ namespace Google.ProtocolBuffers.FieldAccess {
       get { return messageProperty.PropertyType; }
     }
 
-    internal SinglePrimitiveAccessor(string name, Type messageType, Type builderType) {
-      messageProperty = messageType.GetProperty(name);
-      builderProperty = builderType.GetProperty(name);
-      hasProperty = messageType.GetProperty("Has" + name);
-      clearMethod = builderType.GetMethod("Clear" + name);
+    internal SinglePrimitiveAccessor(string name) {
+      messageProperty = typeof(TMessage).GetProperty(name);
+      builderProperty = typeof(TBuilder).GetProperty(name);
+      PropertyInfo hasProperty = typeof(TMessage).GetProperty("Has" + name);
+      MethodInfo clearMethod = typeof(TBuilder).GetMethod("Clear" + name);
       if (messageProperty == null || builderProperty == null || hasProperty == null || clearMethod == null) {
         throw new ArgumentException("Not all required properties/methods available");
       }
+      hasDelegate = (HasDelegate<TMessage>)Delegate.CreateDelegate(typeof(HasDelegate<TMessage>), hasProperty.GetGetMethod());
+      clearDelegate = (ClearDelegate<TBuilder>)Delegate.CreateDelegate(typeof(ClearDelegate<TBuilder>), clearMethod);
     }
 
-    public bool Has(IMessage message) {
-      return (bool) hasProperty.GetValue(message, null);
+    public bool Has(TMessage message) {
+      return hasDelegate(message);
     }
 
-    public void Clear(IBuilder builder) {
-      clearMethod.Invoke(builder, null);
+    public void Clear(TBuilder builder) {
+      clearDelegate(builder);
     }
 
     /// <summary>
@@ -60,16 +64,16 @@ namespace Google.ProtocolBuffers.FieldAccess {
       throw new InvalidOperationException();
     }
 
-    public virtual object GetValue(IMessage message) {
+    public virtual object GetValue(TMessage message) {
       return messageProperty.GetValue(message, null);
     }
 
-    public virtual void SetValue(IBuilder builder, object value) {
+    public virtual void SetValue(TBuilder builder, object value) {
       builderProperty.SetValue(builder, value, null);
     }
 
     #region Methods only related to repeated values
-    public int GetRepeatedCount(IMessage message) {
+    public int GetRepeatedCount(TMessage message) {
       throw new InvalidOperationException();
     }
 

csharp/ProtocolBuffers/GeneratedBuilder.cs

@@ -34,8 +34,8 @@ namespace Google.ProtocolBuffers {
     /// </summary>
     protected abstract TMessage MessageBeingBuilt { get; }
 
-    protected internal FieldAccessorTable InternalFieldAccessors {
-      get { return MessageBeingBuilt.FieldAccesseorsFromBuilder; }
+    protected internal FieldAccessorTable<TMessage, TBuilder> InternalFieldAccessors {
+      get { return MessageBeingBuilt.FieldAccessorsFromBuilder; }
     }
 
     public override bool IsInitialized {
@@ -104,7 +104,7 @@ namespace Google.ProtocolBuffers {
     }
 
     public override TBuilder ClearField(FieldDescriptor field) {
-      InternalFieldAccessors[field].Clear(this);
+      InternalFieldAccessors[field].Clear(ThisBuilder);
       return ThisBuilder;
     }
 

csharp/ProtocolBuffers/GeneratedMessage.cs

@@ -33,11 +33,16 @@ namespace Google.ProtocolBuffers {
 
     private UnknownFieldSet unknownFields = UnknownFieldSet.DefaultInstance;
 
-    internal FieldAccessorTable FieldAccesseorsFromBuilder {
+    /// <summary>
+    /// Returns the message as a TMessage.
+    /// </summary>
+    protected abstract TMessage ThisMessage { get; }
+
+    internal FieldAccessorTable<TMessage, TBuilder> FieldAccessorsFromBuilder {
       get { return InternalFieldAccessors; }
     }
 
-    protected abstract FieldAccessorTable InternalFieldAccessors { get; }
+    protected abstract FieldAccessorTable<TMessage, TBuilder> InternalFieldAccessors { get; }
 
     public override MessageDescriptor DescriptorForType {
       get { return InternalFieldAccessors.Descriptor; }
@@ -49,13 +54,13 @@ namespace Google.ProtocolBuffers {
       var ret = new SortedList<FieldDescriptor, object>();
       MessageDescriptor descriptor = DescriptorForType;
       foreach (FieldDescriptor field in descriptor.Fields) {
-        IFieldAccessor accessor = InternalFieldAccessors[field];
+        IFieldAccessor<TMessage, TBuilder> accessor = InternalFieldAccessors[field];
         if (field.IsRepeated) {
-          if (accessor.GetRepeatedCount(this) != 0) {
-            ret[field] = accessor.GetValue(this);
+          if (accessor.GetRepeatedCount(ThisMessage) != 0) {
+            ret[field] = accessor.GetValue(ThisMessage);
           }
         } else if (HasField(field)) {
-          ret[field] = accessor.GetValue(this);
+          ret[field] = accessor.GetValue(ThisMessage);
         }
       }
       return ret;
@@ -99,11 +104,11 @@ namespace Google.ProtocolBuffers {
     }
 
     public override bool HasField(FieldDescriptor field) {
-      return InternalFieldAccessors[field].Has(this);
+      return InternalFieldAccessors[field].Has(ThisMessage);
     }
 
     public override int GetRepeatedFieldCount(FieldDescriptor field) {
-      return InternalFieldAccessors[field].GetRepeatedCount(this);
+      return InternalFieldAccessors[field].GetRepeatedCount(ThisMessage);
     }
 
     public override object this[FieldDescriptor field, int index] {
@@ -111,7 +116,7 @@ namespace Google.ProtocolBuffers {
     }
 
     public override object this[FieldDescriptor field] {
-      get { return InternalFieldAccessors[field].GetValue(this); }
+      get { return InternalFieldAccessors[field].GetValue(ThisMessage); }
     }
 
     public override UnknownFieldSet UnknownFields {

csharp/ProtocolBuffers/ProtocolBuffers.csproj

@@ -34,6 +34,8 @@
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="System" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
     <Compile Include="AbstractBuilder.cs" />
@@ -69,6 +71,7 @@
     <Compile Include="ExtendableMessage.cs" />
     <Compile Include="ExtensionInfo.cs" />
     <Compile Include="ExtensionRegistry.cs" />
+    <Compile Include="FieldAccess\Delegates.cs" />
     <Compile Include="FieldAccess\SingleEnumAccessor.cs" />
     <Compile Include="FieldAccess\SingleMessageAccessor.cs" />
     <Compile Include="FieldAccess\SinglePrimitiveAccessor.cs" />

src/google/protobuf/compiler/csharp/csharp_message.cc

@@ -175,8 +175,8 @@ void MessageGenerator::GenerateStaticVariables(io::Printer* printer) {
 
   // And the FieldAccessorTable.
   printer->Print(vars,
-    "$private$static pb::FieldAccess.FieldAccessorTable internal__$identifier$__FieldAccessorTable\r\n"
-    "    = new pb::FieldAccess.FieldAccessorTable(internal__$identifier$__Descriptor,\r\n"
+    "$private$static pb::FieldAccess.FieldAccessorTable<$classname$, $classname$.Builder> internal__$identifier$__FieldAccessorTable\r\n"
+    "    = new pb::FieldAccess.FieldAccessorTable<$classname$, $classname$.Builder>(internal__$identifier$__Descriptor,\r\n"
     "        new string[] { ");
   for (int i = 0; i < descriptor_->field_count(); i++) {
     printer->Print(
@@ -184,10 +184,7 @@ void MessageGenerator::GenerateStaticVariables(io::Printer* printer) {
       "field_name",
         UnderscoresToCapitalizedCamelCase(descriptor_->field(i)));
   }
-  printer->Print("},\r\n"
-    "        typeof ($classname$),\r\n"
-    "        typeof ($classname$.Builder));\r\n",
-    "classname", ClassName(descriptor_));
+  printer->Print("});\r\n");
 
   // Generate static members for all nested types.
   for (int i = 0; i < descriptor_->nested_type_count(); i++) {
@@ -225,17 +222,26 @@ void MessageGenerator::Generate(io::Printer* printer) {
     "}\r\n"
     "\r\n",
     "classname", descriptor_->name());
+
   printer->Print(
+      "protected override $classname$ ThisMessage {\r\n"
+      "  get { return this; }\r\n"
+      "}\r\n\r\n",
+      "classname", descriptor_->name());
+
+  map<string, string> vars;
+  vars["identifier"] = UniqueFileScopeIdentifier(descriptor_);
+  vars["fileclass"] = ClassName(descriptor_->file());
+  vars["classname"] = descriptor_->name();
+  printer->Print(vars,
     "public static pbd::MessageDescriptor Descriptor {\r\n"
     "  get { return $fileclass$.internal__$identifier$__Descriptor; }\r\n"
     "}\r\n"
     "\r\n"
-    "protected override pb::FieldAccess.FieldAccessorTable InternalFieldAccessors {\r\n"
+    "protected override pb::FieldAccess.FieldAccessorTable<$classname$, $classname$.Builder> InternalFieldAccessors {\r\n"
     "  get { return $fileclass$.internal__$identifier$__FieldAccessorTable; }\r\n"
     "}\r\n"
-    "\r\n",
-    "fileclass", ClassName(descriptor_->file()),
-    "identifier", UniqueFileScopeIdentifier(descriptor_));
+    "\r\n");
 
   // Extensions don't need to go in an extra nested type
   for (int i = 0; i < descriptor_->extension_count(); i++) {