[ROOT] TMemberInspector and constant data members

From: Gora Mohanty (gora@solar2.ucr.edu)
Date: Mon Dec 03 2001 - 03:29:31 MET


Hello,
  I am having a problem with using constant data members in classes that are
then compiled into ROOT. The problem seems to be that the ShowMembers()
function calls TMemberInspector::Inspect() with a pointer to the constant data
member, while TMemberInspector::Inspect() is expecting a void* pointer, i.e.,
a const void* cannot be converted into a void*. I have worked around this
problem by overloading TMemberInspector::Inspect() with a version that does
take a const void*, viz.,
  virtual void Inspect(TClass *cl, const char *parent, const char *name,
                       const void *addr) = 0;

I also had to modify TObject.cxx and TClass.cxx, that define classes deriving
from TMemberInspector, so as to provide a definition for this pure virtual
function. I have done this by simply calling the non-const version of Inspect
with a const_cast, e.g., in TObject.cxx to the class TDumpMembers I have added
   void Inspect(TClass *cl, const char *parent, const char *name,
                const void *addr) {
     return Inspect( cl, parent, name, const_cast<void*>(addr) ); }
Is there any problem in doing this? If not, could some such modification be
done in future releases, so that I do not have  to do this each time? If it
matters, I am using ROOT version 3.01.06 compiled with gcc3.0 on a SuSE Linux
7.1 box, but have also had the same problem with older versions of ROOT.

Regards,
Gora



This archive was generated by hypermail 2b29 : Tue Jan 01 2002 - 17:51:10 MET