tbb::task_arena is an alias of tbb::interface7::task_arena, which doesn't allow to forward declare tbb::task_arena without forward declaring tbb::interface7 | root.cern
1// @(#)root/win32gdk:$Id$| root.cern
#include "TGWin32ProxyDefs.h"| root.cern
65class TCollection : public TObject {| root.cern