+class UndoGroupHelper::Impl {
+ friend class UndoGroupHelper;
+ set<Buffer *> buffers_;
+};
+
+
+UndoGroupHelper::UndoGroupHelper(Buffer * buf) : d(new UndoGroupHelper::Impl)
+{
+ resetBuffer(buf);
+}
+
+
+UndoGroupHelper::~UndoGroupHelper()
+{
+ for (Buffer * buf : d->buffers_)
+ if (theBufferList().isLoaded(buf) || theBufferList().isInternal(buf))
+ buf->undo().endUndoGroup();
+ delete d;
+}
+