Extract the declaration sorting into its own pass.

src/Generator/Driver.cs

@@ -41,14 +41,11 @@ namespace Cxxi
 
         public void ProcessCode()
         {
-            // Sort the declarations to be in original order.
-            foreach (var unit in library.TranslationUnits)
-                SortDeclarations(unit);
-
             if (transform != null)
                 transform.Preprocess(new LibraryHelpers(library));
 
             var passes = new PassBuilder(library);
+            passes.SortDeclarations();
             passes.ResolveIncompleteDecls(typeDatabase);
             passes.CleanInvalidDeclNames();
             passes.CheckFlagEnums();
@@ -63,15 +60,6 @@ namespace Cxxi
                 transform.Postprocess(new LibraryHelpers(library));
         }
 
-        private static void SortDeclarations(Namespace @namespace)
-        {
-            @namespace.Classes.Sort((c, c1) =>
-                              (int) (c.DefinitionOrder - c1.DefinitionOrder));
-
-            foreach (var childNamespace in @namespace.Namespaces)
-                SortDeclarations(childNamespace);
-        }
-
         public void GenerateCode()
         {
             if (library.TranslationUnits.Count <= 0)

src/Generator/Passes/SortDeclarationsPass.cs

@@ -0,0 +1,36 @@
+using Cxxi.Types;
+
+namespace Cxxi.Passes
+{
+    class SortDeclarationsPass : TranslationUnitPass
+    {
+        public SortDeclarationsPass()
+        {
+            
+        }
+
+        private static void SortDeclarations(Namespace @namespace)
+        {
+            @namespace.Classes.Sort((c, c1) =>
+                                    (int)(c.DefinitionOrder - c1.DefinitionOrder));
+
+            foreach (var childNamespace in @namespace.Namespaces)
+                SortDeclarations(childNamespace);
+        }
+
+        public override bool ProcessUnit(TranslationUnit unit)
+        {
+            SortDeclarations(unit);
+            return true;
+        }
+    }
+
+    public static class SortDeclarationsExtensions
+    {
+        public static void SortDeclarations(this PassBuilder builder)
+        {
+            var pass = new SortDeclarationsPass();
+            builder.AddPass(pass);
+        }
+    }
+}