use new ControlList::add() argument

[ardour.git] / libs / pbd / pbd / command.h

diff --git a/libs/pbd/pbd/command.h b/libs/pbd/pbd/command.h
index c6c3c8d3fd21b02d818be71e00fbdc4e150aa990..4547b779fb4e736300305017012e6246dfa66ba9 100644 (file)
--- a/libs/pbd/pbd/command.h
+++ b/libs/pbd/pbd/command.h
@@ -24,10 +24,11 @@
 
 #include <string>
 
+#include "pbd/libpbd_visibility.h"
 #include "pbd/signals.h"
 #include "pbd/statefuldestructible.h"
 
-class Command : public PBD::StatefulDestructible, public PBD::ScopedConnectionList
+class LIBPBD_API Command : public PBD::StatefulDestructible, public PBD::ScopedConnectionList
 {
 public:
        virtual ~Command() { /* NOTE: derived classes must call drop_references() */ }
@@ -43,6 +44,10 @@ public:
        virtual XMLNode &get_state();
        virtual int set_state(const XMLNode&, int /*version*/) { /* noop */ return 0; }
 
+       virtual bool empty () const {
+               return false;
+       }
+
 protected:
        Command() {}
        Command(const std::string& name) : _name(name) {}