#include "TFile.h"
#include "TTree.h"
#include "TChain.h"


class A : public TObject {
public:
	A()
	{
		x = 0;
	};
	ClassDef(A, 1);
	
	int x;
};


class B : public TObject {
public:
	B()
	{
		x = 0;
	};
	ClassDef(B, 1);
	
	int x;
	
	int function1()
	{
		return (x * x);
	};
	
	int function2(int y)
	{
		return (x * y);
	};
	
	int function3(A* a)
	{
		return (x * a->x);
	};

};


void test() {
	TFile* file = new TFile("test.root", "RECREATE");
	TTree* tree = new TTree("tree", "tree");
	
	A* a = new A();
	B* b = new B();
	tree->Branch("a", "A", &a);
	tree->Branch("b", "B", &b);

	for (int i = 0; i < 100; ++i)
	{
		a->x = i;
		b->x = i * 10;
		tree->Fill();
	}

	tree->Write();
	file->Close();
	
	TChain* chain = new TChain("tree");
	chain->Add("test.root");
	
	// chain->Draw("a.x"); // works
	// chain->Draw("b.x"); // works
	// chain->Draw("b.function1()"); // works
	
	// the following does not work
	// Unknown method:function2(a.x) in B 
// 	chain->Draw("b->function2(a->x)");
	// the following does not work and leads to segfaults
// 	chain->Draw("b->function3(a)");
}