try this:
((TMyString*)l->FindObject("b"))->Data()
FindObject() returns a TObject* and Data() is not a TObject
member function, therefore you need to cast the FindObject()
result to a TMyString* before calling Data().
Note, ClassName() and GetName() are TObject member functions
and therefore they can be called directly via FindObject().
Cheers, Fons.
PS: there is a ROOT TObjString class that is doing most of what
your TMyString is doing. It uses TString containment instead
of multiple inheritance though.
PS2: default base class contstructors don't have to
be explicitely called. E.g.:
TMyString() { }
TMyString(Ssiz_t ic) : TString(ic) { }
>
> Dear ROOT team.
>
> The following is my toy TObjString class :
> --------------------------------------------------
> #ifndef __TMyString_H__
> #define __TMyString_H__
>
> #include "TObject.h"
> #include "TString.h"
>
> class TMyString : public TObject, public TString {
> public:
> TMyString() : TObject(),TString() {};
> TMyString(Ssiz_t ic) : TObject(),TString(ic) {};
> TMyString(TString& s) : TObject(),TString(s) {};
> TMyString(char* s) : TObject(),TString(s) {};
> TMyString(char c) : TObject(),TString(c) {};
> TMyString(char c, Ssiz_t s) : TObject(),TString(c,s) {};
> TMyString(TSubString& sub) : TObject(),TString(sub) {};
> TMyString(char* s, Ssiz_t n) : TObject(),TString(s,n) {};
> virtual ~TMyString() {};
> const char *GetName() const { return Data(); };
> ClassDef(TMyString,1) // Toy TObjString class
> };
> #endif
> ----------------------------------------------------
> I compile it to TMyString.so and load into root - OK.
> I can write and read objects of TMyString to TFile - looks OK.
> But when I insert TMyString* pointers to TList and retrive it back -
> I cannot access the methods of TString part of TMyString !
> Why ?
> The following is a my 'root session' :
> *******************************************
> * *
> * W E L C O M E to R O O T *
> * *
> * Version 2.00/08 5 June 1998 *
> * *
> * You are welcome to visit our Web site *
> * http://root.cern.ch *
> * *
> *******************************************
>
> CINT/ROOT C/C++ Interpreter version 5.13.55, May 16 1998
> Type ? for help. Commands must be C++ statements.
> Enclose multiple statements between { }.
> root [0] gSystem->Load("TMyString.so")
> (int)0
> root [1] TMyString s="abc"
> root [2] s.Data()
> (char* 0x855f28c)"abc"
> root [3] s.Dump()
> fUniqueID 0 object unique identifier
> fBits 50331648 bit field status word
> *fData abc
> root [4] TList *l=new TList()
> root [5] TMyString *p=new TMyString("a")
> root [6] l->Add(p)
> root [7] p=new TMyString("b")
> (class TMyString*)0x85c7e20
> root [8] l->Add(p)
> root [9] p=new TMyString("c")
> (class TMyString*)0x85c7de8
> root [10] l->Add(p)
> root [11] l->Dump()
> fUniqueID 0 object unique identifier
> fBits 50331648 bit field status word
> *fData a
> fUniqueID 0 object unique identifier
> fBits 50331648 bit field status word
> *fData b
> fUniqueID 0 object unique identifier
> fBits 50331648 bit field status word
> *fData c
> root [12] TMyString *o=l->FindObject("b")
> root [13] o->ClassName()
> (Text_t* 0x855f3ec)"TMyString"
> root [14] o->GetName()
> (char* 0x85c7e54)"b"
> root [15] o->Data()
> (char* 0x85c7e54)"b"
> root [16] l->FindObject("b")->Data()
> Error: Can't call TObject::Data() in current scope FILE:/tmp/17810raa
> LINE:1
> Error: non class,struct,union object FindObject("b") used with . or ->
> FILE:/tmp/17810raa LINE:1
> *** Interpreter error recovered ***
> root [17] l->FindObject("b")->GetName()
> (Text_t* 0x85c7e54)"b"
> root [18] l->FindObject("b")->ClassName()
> (Text_t* 0x855f3ec)"TMyString"
>
>
> Why CINT having correct ClassName cannot call to 'Data()' method ?
>
> Best regards,
> Nikolay Root
> BINP, Novosibirsk
> email : nroot@inp.nsk.su
>
-- Org: CERN, European Laboratory for Particle Physics. Mail: 1211 Geneve 23, Switzerland Phone: +41 22 7679248 E-Mail: Fons.Rademakers@cern.ch Fax: +41 22 7677910