When i try to call        DSIDebug::SetDebug(BOOL bDebugOn_   )   from myviewcontroller.mm file   it shows error like  
"DSIDebug::SetDebug(signed char)", referenced from:
      -[viewdisplay InitDemo::] in viewdisplay.o
ld: symbol(s) not found for architecture x86_64"
can i get some help about this?