Problem with splitting a ROOT class

[AndrewC]

I have a TObject defined below

class Muon_Track : public TObject {
public:
    Int_t n = 0;
    Double_t *X;      //[n]
    TFitResult fit[3];

    Double_t chi2[3]; 
    TVector3 v;        
    TVector3 r0;       
    TVector3 vError; 
    TVector3 r0Error; 
	
    Muon_Track();
    ~Muon_Track();
    
    void Fit(); // sets fit, chi2, v,r0,vError,r0Error

private:
    Color_t markerColour = kBlue+2; //!
    Color_t lineColour = kBlue+2;   //!
    Style_t markerStyle = 20;       //!
    
    ClassDef(Muon_Track,1)
};

And I’m trying to write to it using the following

// File and Tree for output
TFile fOut(output.c_str(), "recreate");
TTree tOut("t", "Muon Track Tree");

Muon_Track* M = new Muon_Track();
M->X = new Double_t[MAXN];

tOut.Branch("M","Muon_Track",&M,8000,1);

...
std::vector<Double_t> X_vec;
...
X_vec.push_back(some_value);
...
M->X = X_vec.data();
tOut.Fill();

When I try to run the executable I get the following output

Warning in <TTree::Bronch>: Muon_Track cannot be split, resetting splitlevel to 0

It works just fine with the root interpreter though

Makefile.txt (1.1 KB)

[pcanal]

Did you use

#pragma link C++ class  Muon_Track+;

(note the trailing +) in the LinkDef.h file?

[AndrewC]

No, LinkDef.h looks like:

#ifdef __CINT__
#pragma link C++ class Muon_Track;
#endif

[pcanal]

This is the problem. Without the +, this request the old style I/O for that class and that does not support splitting.
Add the + and regenerate the dictionary and it should work as expected.

Cheers,
Philippe.

[AndrewC]

That worked, thankyou!