matthias Solved the clang/MacOS startup failure and menu issue …

1.) Startup issue:

This is solved by making sure templates with virtual functions
are made visible in the DSO. This way, dynamic_cast is possible
across DSO's.

Scary: clang/MacOS wants the forward declarations be declared visible as well.

2.) Menu issue:

The best solution is to have only one QMenuBar. The navigator
now gets a synthetic menu bar composed of QToolButtons.

src/ant/ant/antCommon.h

@@ -35,7 +35,7 @@
 
 # else
 
-#   if __GNUC__ >= 4
+#   if __GNUC__ >= 4 || defined(__clang__)
 #     define ANT_PUBLIC __attribute__ ((visibility ("default")))
 #     define ANT_LOCAL  __attribute__ ((visibility ("hidden")))
 #   else

src/buddies/src/bd/bdCommon.h

@@ -35,7 +35,7 @@
 
 # else
 
-#   if __GNUC__ >= 4
+#   if __GNUC__ >= 4 || defined(__clang__)
 #     define BD_PUBLIC __attribute__ ((visibility ("default")))
 #     define BD_LOCAL  __attribute__ ((visibility ("hidden")))
 #   else

src/db/db/dbBox.h

@@ -57,7 +57,7 @@ class ArrayRepository;
  */
 
 template <class C, class R = C>
-struct box
+struct DB_PUBLIC box
 {
   typedef C coord_type;
   typedef box<C, R> box_type;

src/db/db/dbCommon.h

@@ -35,7 +35,7 @@
 
 # else
 
-#   if __GNUC__ >= 4
+#   if __GNUC__ >= 4 || defined(__clang__)
 #     define DB_PUBLIC __attribute__ ((visibility ("default")))
 #     define DB_LOCAL  __attribute__ ((visibility ("hidden")))
 #   else

src/db/db/dbEdge.h

@@ -42,7 +42,7 @@ template <class C> class generic_repository;
 class ArrayRepository;
 
 template <class C>
-class edge
+class DB_PUBLIC edge
 {
 public:
   typedef C coord_type;

src/db/db/dbEdgePair.h

@@ -40,7 +40,7 @@
 namespace db {
 
 template <class C>
-class edge_pair
+class DB_PUBLIC edge_pair
 {
 public:
   typedef C coord_type;

src/db/db/dbPoint.h

@@ -43,7 +43,7 @@ template <class C> class vector;
  */
 
 template <class C>
-class point 
+class DB_PUBLIC point
 {
 public:
   typedef C coord_type;

src/db/db/dbPolygon.h

@@ -1364,7 +1364,7 @@ private:
  */
 
 template <class C>
-class polygon
+class DB_PUBLIC polygon
 {
 public:
   typedef C coord_type;
@@ -2324,7 +2324,7 @@ private:
  */
 
 template <class C>
-class simple_polygon
+class DB_PUBLIC simple_polygon
 {
 public:
   typedef C coord_type;

src/db/db/dbText.h

@@ -222,7 +222,7 @@ private:
  */
 
 template <class C>
-class text
+class DB_PUBLIC text
 {
 public:
   typedef C coord_type;

src/db/db/dbTrans.h

@@ -42,8 +42,8 @@ namespace tl {
 
 namespace db {
 
-template <class I, class F, class R = double> class complex_trans;
+template <class I, class F, class R = double> class DB_PUBLIC complex_trans;
-template <class C> class simple_trans;
+template <class C> class DB_PUBLIC simple_trans;
 template <class C> class disp_trans;
 template <class C> class fixpoint_trans;
 
@@ -1035,7 +1035,7 @@ operator<< (std::ostream &os, const disp_trans<C> &t)
  */
 
 template <class C>
-class simple_trans
+class DB_PUBLIC simple_trans
   : public fixpoint_trans<C>
 {
 public:
@@ -1439,7 +1439,7 @@ operator<< (std::ostream &os, const simple_trans<C> &t)
  *  type used internally for representing the floating-point members).
  */
 template <class I, class F, class R>
-class complex_trans
+class DB_PUBLIC complex_trans
 {
 public:
   typedef I coord_type;

src/db/db/dbVector.h

@@ -45,7 +45,7 @@ template <class C> class point;
  */
 
 template <class C>
-class vector 
+class DB_PUBLIC vector
 {
 public:
   typedef C coord_type;

src/drc/drc/drcCommon.h

@@ -35,7 +35,7 @@
 
 # else
 
-#   if __GNUC__ >= 4
+#   if __GNUC__ >= 4 || defined(__clang__)
 #     define DRC_PUBLIC __attribute__ ((visibility ("default")))
 #     define DRC_LOCAL  __attribute__ ((visibility ("hidden")))
 #   else

src/edt/edt/edtCommon.h

@@ -35,7 +35,7 @@
 
 # else
 
-#   if __GNUC__ >= 4
+#   if __GNUC__ >= 4 || defined(__clang__)
 #     define EDT_PUBLIC __attribute__ ((visibility ("default")))
 #     define EDT_LOCAL  __attribute__ ((visibility ("hidden")))
 #   else

src/ext/ext/extCommon.h

@@ -35,7 +35,7 @@
 
 # else
 
-#   if __GNUC__ >= 4
+#   if __GNUC__ >= 4 || defined(__clang__)
 #     define EXT_PUBLIC __attribute__ ((visibility ("default")))
 #     define EXT_LOCAL  __attribute__ ((visibility ("hidden")))
 #   else

src/gsi/gsi/gsiClass.h

@@ -116,7 +116,7 @@ void _var_user_read_impl (T * /*a*/, tl::Extractor & /*ex*/, tl::false_tag)
  *  @brief A VariantUserClassBase specialization that links GSI classes and Variant classes
  */
 template <class T>
-class VariantUserClass
+class GSI_PUBLIC VariantUserClass
   : public tl::VariantUserClass<T>, private VariantUserClassImpl
 {
 public:
@@ -551,7 +551,7 @@ public:
  *  the given methods.
  */
 template <class X>
-class ClassExt
+class GSI_PUBLIC ClassExt
   : public ClassBase
 {
 public:
@@ -708,7 +708,7 @@ struct adaptor_type_info<X, NoAdaptorTag>
  *  or to call it's methods in some generic way.
  */
 template <class X, class Adapted = NoAdaptorTag>
-class Class
+class GSI_PUBLIC Class
   : public ClassBase
 {
 public:
@@ -937,7 +937,7 @@ public:
  *  a subclass of the parent.
  */
 template <class P, class X, class Adapted = NoAdaptorTag>
-class ChildClass
+class GSI_PUBLIC ChildClass
   : public Class<X, Adapted>
 {
 public:
@@ -970,7 +970,7 @@ public:
  *  a subclass of the parent.
  */
 template <class P, class X, class B, class Adapted = NoAdaptorTag>
-class ChildSubClass
+class GSI_PUBLIC ChildSubClass
   : public SubClass<X, B, Adapted>
 {
 public:

src/gsi/gsi/gsiCommon.h

@@ -35,7 +35,7 @@
 
 # else
 
-#   if __GNUC__ >= 4
+#   if __GNUC__ >= 4 || defined(__clang__)
 #     define GSI_PUBLIC __attribute__ ((visibility ("default")))
 #     define GSI_LOCAL  __attribute__ ((visibility ("hidden")))
 #   else

src/gsi/gsi/gsiExpression.h

@@ -34,9 +34,9 @@
 namespace gsi 
 {
 
-class ClassBase;
+class GSI_PUBLIC ClassBase;
 struct NoAdaptorTag;
-template <class T, class A> class Class;
+template <class T, class A> class GSI_PUBLIC Class;
 
 /**
  *  @brief The implementation delegate for the VariantUserClass<T>

src/gsi/gsi/gsiObject.h

@@ -35,7 +35,7 @@
 namespace gsi
 {
 
-class ClassBase;
+class GSI_PUBLIC ClassBase;
 
 /**
  *  @brief Definition of the client indexes

src/gsi/gsi/gsiObjectHolder.h

@@ -30,7 +30,7 @@
 namespace gsi
 {
 
-class ClassBase;
+class GSI_PUBLIC ClassBase;
 
 /**
  *  @brief Implements an object holder

src/gsi/gsi/gsiTypes.h

@@ -55,19 +55,19 @@ namespace gsi
 // ---------------------------------------------------------------------------------
 //  Type system of GSI
 
-class SerialArgs;
+class GSI_PUBLIC SerialArgs;
-class VectorAdaptor;
+class GSI_PUBLIC VectorAdaptor;
-class MapAdaptor;
+class GSI_PUBLIC MapAdaptor;
-class StringAdaptor;
+class GSI_PUBLIC StringAdaptor;
-class VariantAdaptor;
+class GSI_PUBLIC VariantAdaptor;
-class ClassBase;
+class GSI_PUBLIC ClassBase;
 struct NoAdaptorTag;
-template <class X, class A> class Class;
+template <class X, class A> class GSI_PUBLIC Class;
 template <class X> struct ClassTag;
-template <class I> class IterAdaptor;
+template <class I> class GSI_PUBLIC IterAdaptor;
-template <class V> class IterPtrAdaptor;
+template <class V> class GSI_PUBLIC IterPtrAdaptor;
-template <class V> class ConstIterPtrAdaptor;
+template <class V> class GSI_PUBLIC ConstIterPtrAdaptor;
-template <class I> class FreeIterAdaptor;
+template <class I> class GSI_PUBLIC FreeIterAdaptor;
 template <class X> const ClassBase *cls_decl ();
 
 /**

src/gsiqt/gsiQtCommon.h

@@ -35,7 +35,7 @@
 
 # else
 
-#   if __GNUC__ >= 4
+#   if __GNUC__ >= 4 || defined(__clang__)
 #     define GSIQT_PUBLIC __attribute__ ((visibility ("default")))
 #     define GSIQT_LOCAL  __attribute__ ((visibility ("hidden")))
 #   else

src/img/img/imgCommon.h

@@ -35,7 +35,7 @@
 
 # else
 
-#   if __GNUC__ >= 4
+#   if __GNUC__ >= 4 || defined(__clang__)
 #     define IMG_PUBLIC __attribute__ ((visibility ("default")))
 #     define IMG_LOCAL  __attribute__ ((visibility ("hidden")))
 #   else

src/lay/lay/layCommon.h

@@ -35,7 +35,7 @@
 
 # else
 
-#   if __GNUC__ >= 4
+#   if __GNUC__ >= 4 || defined(__clang__)
 #     define LAY_PUBLIC __attribute__ ((visibility ("default")))
 #     define LAY_LOCAL  __attribute__ ((visibility ("hidden")))
 #   else

src/lay/lay/layNativePlugin.h

@@ -55,7 +55,7 @@ typedef void (*klp_init_func_t) (void (**autorun) (), void (**autorun_early) (),
 # if defined _WIN32 || defined __CYGWIN__
 #   define KLP_PUBLIC __declspec(dllexport)
 # else
-#   if __GNUC__ >= 4
+#   if __GNUC__ >= 4 || defined(__clang__)
 #     define KLP_PUBLIC __attribute__ ((visibility ("default")))
 #   else
 #     define KLP_PUBLIC

src/lay/lay/layNavigator.cc

@@ -30,7 +30,7 @@
 #include "imgService.h"
 
 #include <QVBoxLayout>
-#include <QMenuBar>
+#include <QFrame>
 #include <QLabel>
 
 namespace lay
@@ -443,7 +443,8 @@ Navigator::Navigator (MainWindow *main_window)
 {
   setObjectName (QString::fromUtf8 ("navigator"));
 
-  mp_menu_bar = new QMenuBar (this);
+  mp_menu_bar = new QFrame (this);
+  mp_menu_bar->setFrameShape (QFrame::NoFrame);
   mp_menu_bar->setSizePolicy (QSizePolicy::Expanding, QSizePolicy::Preferred);
 
   mp_view = new LayoutView (0, false, mp_main_window, this, "navigator", LayoutView::LV_Naked + LayoutView::LV_NoZoom + LayoutView::LV_NoServices + LayoutView::LV_NoGrid);

src/lay/lay/layNavigator.h

@@ -33,7 +33,7 @@
 
 class QCloseEvent;
 class QShowEvent;
-class QMenuBar;
+class QFrame;
 class QLabel;
 
 namespace lay
@@ -102,7 +102,7 @@ private:
   MainWindow *mp_main_window;  
   LayoutView *mp_view;  
   QLabel *mp_placeholder_label;  
-  QMenuBar *mp_menu_bar;
+  QFrame *mp_menu_bar;
   LayoutView *mp_source_view;
   NavigatorService *mp_service;
   tl::DeferredMethod<Navigator> m_do_view_changed;

src/laybasic/laybasic/layAbstractMenu.cc

@@ -37,6 +37,7 @@
 #include <QToolButton>
 #include <QApplication>
 #include <QMessageBox>
+#include <QHBoxLayout>
 
 #include <ctype.h>
 
@@ -903,31 +904,61 @@ AbstractMenu::make_exclusive_group (const std::string &name)
 }
 
 void 
-AbstractMenu::build_detached (const std::string &name, QMenuBar *mbar)
+AbstractMenu::build_detached (const std::string &name, QFrame *mbar)
 {
+  //  Clean up the menu bar before rebuilding
+  if (mbar->layout ()) {
+    delete mbar->layout ();
+  }
+  QObjectList children = mbar->children ();
+  for (QObjectList::const_iterator c = children.begin (); c != children.end (); ++c) {
+    if (dynamic_cast<QToolButton *> (*c)) {
+      delete *c;
+    }
+  }
+
+  QHBoxLayout *menu_layout = new QHBoxLayout (mbar);
+  menu_layout->setMargin (0);
+  mbar->setLayout (menu_layout);
+
   AbstractMenuItem *item = find_item_exact ("@@" + name);
   tl_assert (item != 0);
 
-  mbar->clear ();
-
   for (std::list<AbstractMenuItem>::iterator c = item->children.begin (); c != item->children.end (); ++c) {
 
     if (c->has_submenu ()) {
 
+      QToolButton *menu_button = new QToolButton (mbar);
+      menu_layout->addWidget (menu_button);
+      menu_button->setAutoRaise (true);
+      menu_button->setPopupMode (QToolButton::MenuButtonPopup);
+      menu_button->setText (tl::to_qstring (c->action ().get_title ()));
+
       if (c->menu () == 0) {
-        c->set_menu (mbar->addMenu (tl::to_qstring (c->action ().get_title ())));
+        QMenu *menu = new QMenu (mbar);
-        c->set_action (Action (new ActionHandle (c->menu ()->menuAction (), false)), true);
+        menu_button->setMenu (menu);
+        c->set_menu (menu);
+        c->set_action (Action (new ActionHandle (menu->menuAction (), false)), true);
       } else {
-        mbar->addMenu (c->menu ());
+        menu_button->setMenu (c->menu ());
       }
 
       build (c->menu (), c->children);
 
     } else {
-      mbar->addAction (c->action ().qaction ());
+
+      QAction *action = c->action ().qaction ();
+
+      QToolButton *menu_button = new QToolButton (mbar);
+      menu_layout->addWidget (menu_button);
+      menu_button->setAutoRaise (true);
+      menu_button->setDefaultAction (action);
+
     }
 
   }
+
+  menu_layout->addStretch (1);
 }
 
 void 
@@ -1521,4 +1552,3 @@ AbstractMenu::collect_group (std::vector<std::string> &grp, const std::string &n
 }
 
 }
-

src/laybasic/laybasic/layAbstractMenu.h

@@ -42,6 +42,7 @@
 #include "tlObject.h"
 #include "laybasicCommon.h"
 
+class QFrame;
 class QMenuBar;
 class QToolBar;
 class QMenu;
@@ -681,7 +682,7 @@ public:
    *  @param name The name of the detached menu, without the "@"
    *  @param mbar The menu bar into which to build the menu
    */
-  void build_detached (const std::string &name, QMenuBar *mbar);
+  void build_detached (const std::string &name, QFrame *mbar);
 
   /**
    *  @brief Get the reference to a QMenu object

src/laybasic/laybasic/laybasicCommon.h

@@ -35,7 +35,7 @@
 
 # else
 
-#   if __GNUC__ >= 4
+#   if __GNUC__ >= 4 || defined(__clang__)
 #     define LAYBASIC_PUBLIC __attribute__ ((visibility ("default")))
 #     define LAYBASIC_LOCAL  __attribute__ ((visibility ("hidden")))
 #   else

src/lym/lym/lymCommon.h

@@ -35,7 +35,7 @@
 
 # else
 
-#   if __GNUC__ >= 4
+#   if __GNUC__ >= 4 || defined(__clang__)
 #     define LYM_PUBLIC __attribute__ ((visibility ("default")))
 #     define LYM_LOCAL  __attribute__ ((visibility ("hidden")))
 #   else

src/pya/pya/pyaCommon.h

@@ -35,7 +35,7 @@
 
 # else
 
-#   if __GNUC__ >= 4
+#   if __GNUC__ >= 4 || defined(__clang__)
 #     define PYA_PUBLIC __attribute__ ((visibility ("default")))
 #     define PYA_LOCAL  __attribute__ ((visibility ("hidden")))
 #   else

src/pya/pya/pyaConvert.h

@@ -36,8 +36,8 @@
 
 namespace gsi
 {
-  class ClassBase;
+  class GSI_PUBLIC ClassBase;
-  class ArgType;
+  class GSI_PUBLIC ArgType;
 }
 
 namespace pya

src/pyastub/pyaCommon.h

@@ -35,7 +35,7 @@
 
 # else
 
-#   if __GNUC__ >= 4
+#   if __GNUC__ >= 4 || defined(__clang__)
 #     define PYA_PUBLIC __attribute__ ((visibility ("default")))
 #     define PYA_LOCAL  __attribute__ ((visibility ("hidden")))
 #   else

src/rba/rba/rbaCommon.h

@@ -35,7 +35,7 @@
 
 # else
 
-#   if __GNUC__ >= 4
+#   if __GNUC__ >= 4 || defined(__clang__)
 #     define RBA_PUBLIC __attribute__ ((visibility ("default")))
 #     define RBA_LOCAL  __attribute__ ((visibility ("hidden")))
 #   else

src/rbastub/rbaCommon.h

@@ -35,7 +35,7 @@
 
 # else
 
-#   if __GNUC__ >= 4
+#   if __GNUC__ >= 4 || defined(__clang__)
 #     define RBA_PUBLIC __attribute__ ((visibility ("default")))
 #     define RBA_LOCAL  __attribute__ ((visibility ("hidden")))
 #   else

src/rdb/rdb/rdbCommon.h

@@ -35,7 +35,7 @@
 
 # else
 
-#   if __GNUC__ >= 4
+#   if __GNUC__ >= 4 || defined(__clang__)
 #     define RDB_PUBLIC __attribute__ ((visibility ("default")))
 #     define RDB_LOCAL  __attribute__ ((visibility ("hidden")))
 #   else

src/tl/tl/tlCommon.h

@@ -35,7 +35,7 @@
 
 # else
 
-#   if __GNUC__ >= 4
+#   if __GNUC__ >= 4 || defined(__clang__)
 #     define TL_PUBLIC __attribute__ ((visibility ("default")))
 #     define TL_LOCAL  __attribute__ ((visibility ("hidden")))
 #   else
@@ -45,4 +45,28 @@
 
 # endif
 
+//  NOTE: this is required because we have some forward declarations to
+//  gsi::Class and gsi::ClassBase in tlVariant.h.
+//  TODO: there should not be any dependency of tl on gsi.
+# if defined _WIN32 || defined __CYGWIN__
+
+#   ifdef MAKE_GSI_LIBRARY
+#     define GSI_PUBLIC __declspec(dllexport)
+#   else
+#     define GSI_PUBLIC __declspec(dllimport)
+#   endif
+#   define GSI_LOCAL
+
+# else
+
+#   if __GNUC__ >= 4 || defined(__clang__)
+#     define GSI_PUBLIC __attribute__ ((visibility ("default")))
+#     define GSI_LOCAL  __attribute__ ((visibility ("hidden")))
+#   else
+#     define GSI_PUBLIC
+#     define GSI_LOCAL
+#   endif
+
+# endif
+
 #endif

src/tl/tl/tlEvents.h

@@ -114,12 +114,12 @@ void handle_event_exception (std::exception &ex);
  *  @endcode
  */
 
-template <class A1 = void, class A2 = void, class A3 = void, class A4 = void, class A5 = void> class event_function_base;
+template <class A1 = void, class A2 = void, class A3 = void, class A4 = void, class A5 = void> class TL_PUBLIC event_function_base;
-template <class T, class A1 = void, class A2 = void, class A3 = void, class A4 = void, class A5 = void> class event_function;
+template <class T, class A1 = void, class A2 = void, class A3 = void, class A4 = void, class A5 = void> class TL_PUBLIC event_function;
-template <class T, class D, class A1 = void, class A2 = void, class A3 = void, class A4 = void, class A5 = void> class event_function_with_data;
+template <class T, class D, class A1 = void, class A2 = void, class A3 = void, class A4 = void, class A5 = void> class TL_PUBLIC event_function_with_data;
-template <class T, class A1 = void, class A2 = void, class A3 = void, class A4 = void, class A5 = void> class generic_event_function;
+template <class T, class A1 = void, class A2 = void, class A3 = void, class A4 = void, class A5 = void> class TL_PUBLIC generic_event_function;
-template <class T, class D, class A1 = void, class A2 = void, class A3 = void, class A4 = void, class A5 = void> class generic_event_function_with_data;
+template <class T, class D, class A1 = void, class A2 = void, class A3 = void, class A4 = void, class A5 = void> class TL_PUBLIC generic_event_function_with_data;
-template <class A1 = void, class A2 = void, class A3 = void, class A4 = void, class A5 = void> class event;
+template <class A1 = void, class A2 = void, class A3 = void, class A4 = void, class A5 = void> class TL_PUBLIC event;
 typedef event<> Event;
 
 #define  _COUNT 0

src/tl/tl/tlEventsVar.h

@@ -31,7 +31,7 @@
 #endif
 
 template <_TMPLARGS>
-class event_function_base<_TMPLARGLISTP>
+class TL_PUBLIC event_function_base<_TMPLARGLISTP>
   : public tl::Object
 {
 public:
@@ -42,7 +42,7 @@ public:
 };
 
 template <_JOIN(class T, _TMPLARGS)>
-class event_function<T, _TMPLARGLISTP>
+class TL_PUBLIC event_function<T, _TMPLARGLISTP>
   : public event_function_base<_TMPLARGLIST>
 {
 public:
@@ -71,7 +71,7 @@ private:
 };
 
 template <class T, _JOIN(class D, _TMPLARGS)>
-class event_function_with_data<T, D, _TMPLARGLISTP>
+class TL_PUBLIC event_function_with_data<T, D, _TMPLARGLISTP>
   : public event_function_base<_TMPLARGLIST>
 {
 public:
@@ -101,7 +101,7 @@ private:
 };
 
 template <_JOIN(class T, _TMPLARGS)>
-class generic_event_function<T, _TMPLARGLISTP>
+class TL_PUBLIC generic_event_function<T, _TMPLARGLISTP>
   : public event_function_base<_TMPLARGLIST>
 {
 public:
@@ -131,7 +131,7 @@ private:
 };
 
 template <class T, _JOIN(class D, _TMPLARGS)>
-class generic_event_function_with_data<T, D, _TMPLARGLISTP>
+class TL_PUBLIC generic_event_function_with_data<T, D, _TMPLARGLISTP>
   : public event_function_base<_TMPLARGLIST>
 {
 public:
@@ -162,7 +162,7 @@ private:
 };
 
 template <_TMPLARGS>
-class event<_TMPLARGLISTP>
+class TL_PUBLIC event<_TMPLARGLISTP>
 {
 public:
   typedef event_function_base<_TMPLARGLISTP> func;

src/tl/tl/tlObject.h

@@ -240,7 +240,7 @@ private:
  *  This class represents a weak or shared pointer for the given type T.
  */
 template <class T, bool Shared>
-class weak_or_shared_ptr
+class TL_PUBLIC weak_or_shared_ptr
   : public WeakOrSharedPtr
 {
 public:
@@ -376,7 +376,7 @@ public:
  *  See description of tl::Object for details.
  */
 template <class T>
-class weak_ptr
+class TL_PUBLIC weak_ptr
   : public weak_or_shared_ptr<T, false>
 {
 public:
@@ -404,7 +404,7 @@ public:
  *  See description of tl::Object for details.
  */
 template <class T>
-class shared_ptr
+class TL_PUBLIC shared_ptr
   : public weak_or_shared_ptr<T, true>
 {
 public:

src/tl/tl/tlVariant.h

@@ -42,9 +42,9 @@
 
 namespace gsi
 {
-  class ClassBase;
+  class GSI_PUBLIC ClassBase;
   struct NoAdaptorTag;
-  template <class T, class A> class Class;
+  template <class T, class A> class GSI_PUBLIC Class;
   template <class X> const ClassBase *cls_decl ();
 }
 
@@ -102,7 +102,7 @@ protected:
  *  We will employ RTTI to identify a type through that base class.
  */
 template <class T>
-class VariantUserClass
+class TL_PUBLIC VariantUserClass
   : public VariantUserClassBase
 {
 public: