--- a/dwtx/text/undo/DocumentUndoManager.d	Sun Aug 24 01:52:31 2008 +0200
+++ b/dwtx/text/undo/DocumentUndoManager.d	Sun Aug 24 02:20:40 2008 +0200
@@ -149,8 +149,8 @@
          */
         protected void undoTextChange() {
             try {
-                if (fDocumentUndoManager.fDocument instanceof IDocumentExtension4)
-                    (cast(IDocumentExtension4) fDocumentUndoManager.fDocument).replace(fStart, fText
+                if (auto de4 = cast(IDocumentExtension4)fDocumentUndoManager.fDocument )
+                    de4.replace(fStart, fText
                             .length(), fPreservedText, fUndoModificationStamp);
                 else
                     fDocumentUndoManager.fDocument.replace(fStart, fText.length(),
@@ -164,7 +164,7 @@
          */
         public bool canUndo() {
             if (isValid()) {
-                if (fDocumentUndoManager.fDocument instanceof IDocumentExtension4) {
+                if (cast(IDocumentExtension4)fDocumentUndoManager.fDocument) {
                     long docStamp= (cast(IDocumentExtension4) fDocumentUndoManager.fDocument)
                             .getModificationStamp();
 
@@ -210,7 +210,7 @@
                             && this is fDocumentUndoManager.fHistory
                                     .getUndoOperation(fDocumentUndoManager.fUndoContext)
                             && // this is the latest operation
-                            this instanceof UndoableCompoundTextChange
+                            null !is cast(UndoableCompoundTextChange)this
                             && this is fDocumentUndoManager.fCurrent
                             && // this is the current operation
                             this.fStart is -1
@@ -234,7 +234,7 @@
          */
         public bool canRedo() {
             if (isValid()) {
-                if (fDocumentUndoManager.fDocument instanceof IDocumentExtension4) {
+                if (cast(IDocumentExtension4)fDocumentUndoManager.fDocument ) {
                     long docStamp= (cast(IDocumentExtension4) fDocumentUndoManager.fDocument)
                             .getModificationStamp();
                     return docStamp is IDocumentExtension4.UNKNOWN_MODIFICATION_STAMP
@@ -283,7 +283,7 @@
          */
         protected void redoTextChange() {
             try {
-                if (fDocumentUndoManager.fDocument instanceof IDocumentExtension4)
+                if (cast(IDocumentExtension4)fDocumentUndoManager.fDocument)
                     (cast(IDocumentExtension4) fDocumentUndoManager.fDocument).replace(fStart, fEnd - fStart, fText, fRedoModificationStamp);
                 else
                     fDocumentUndoManager.fDocument.replace(fStart, fEnd - fStart, fText);
@@ -666,7 +666,7 @@
                     // if we are undoing/redoing an operation we generated, then
                     // ignore
                     // the document changes associated with this undo or redo.
-                    if (event.getOperation() instanceof UndoableTextChange) {
+                    if (cast(UndoableTextChange)event.getOperation() ) {
                         listenToTextChanges(false);
 
                         // in the undo case only, make sure compounds are closed
@@ -858,7 +858,7 @@
     /*
      * @see dwtx.text.undo.IDocumentUndoManager#undo()
      */
-    public void redo() throws ExecutionException {
+    public void redo()  {
         if (isConnected() && redoable())
             OperationHistoryFactory.getOperationHistory().redo(getUndoContext(), null, null);
     }
@@ -866,7 +866,7 @@
     /*
      * @see dwtx.text.undo.IDocumentUndoManager#undo()
      */
-    public void undo() throws ExecutionException {
+    public void undo()  {
         if (undoable())
             OperationHistoryFactory.getOperationHistory().undo(fUndoContext, null, null);
     }
@@ -968,7 +968,7 @@
      */
     private void addToOperationHistory(UndoableTextChange edit) {
         if (!fFoldingIntoCompoundChange
-                || edit instanceof UndoableCompoundTextChange) {
+                || cast(UndoableCompoundTextChange)edit ) {
             fHistory.add(edit);
             fLastAddedTextEdit= edit;
         }
@@ -1259,20 +1259,20 @@
         for (int i= 0; i < operations.length; i++) {
             // First replace the undo context
             IUndoableOperation op= operations[i];
-            if (op instanceof IContextReplacingOperation) {
+            if (cast(IContextReplacingOperation)op ) {
                 (cast(IContextReplacingOperation)op).replaceContext(oldUndoContext, getUndoContext());
             } else {
                 op.addContext(getUndoContext());
                 op.removeContext(oldUndoContext);
             }
             // Now update the manager that owns the text edit.
-            if (op instanceof UndoableTextChange) {
+            if (cast(UndoableTextChange)op ) {
                 (cast(UndoableTextChange)op).fDocumentUndoManager= this;
             }
         }
 
         IUndoableOperation op= OperationHistoryFactory.getOperationHistory().getUndoOperation(getUndoContext());
-        if (op !is null && !(op instanceof UndoableTextChange))
+        if (op !is null && !(cast(UndoableTextChange)op ))
             return;
 
         // Record the transfer itself as an undoable change.
@@ -1283,7 +1283,7 @@
         UndoableTextChange cmd= new UndoableTextChange(this);
         cmd.fStart= cmd.fEnd= 0;
         cmd.fText= cmd.fPreservedText= ""; //$NON-NLS-1$
-        if (fDocument instanceof IDocumentExtension4) {
+        if (cast(IDocumentExtension4)fDocument ) {
             cmd.fRedoModificationStamp= (cast(IDocumentExtension4)fDocument).getModificationStamp();
             if (op !is null)
                 cmd.fUndoModificationStamp= (cast(UndoableTextChange)op).fRedoModificationStamp;