Ask for help: Is it correct to use template in this way?

ROOT
1

Hi rooters,

    :cry: I made a class then complied and did a test. But ROOT exited when I call the constuctor. I want to know why?

//----------------- Node.h------------------------------
#ifndef _NODE_H
#define _NODE_H

#include “TObject.h”

template
class Node : public TObject
{
private:
T *fCont;
Node *fLeft;
Node *fRight;
void SetLeft(Node *left) { fLeft=left;}
void SetRight(Node *right) { fRight=right;}

public:
Node();

T *GetCont(){return fCont;}
Node *GetLeft(){ return fLeft;}
Node *GetRight() {return fRight;}

ClassDef(Node,0)

};

#endif

//------------------Node.cxx---------------------

#include “Node.h”

templateClassImp(Node);

template
Node::Node()
{}

//-----------------NodeLinkDef.h---------------

#ifdef CINT
#pragma link off all globals;
#pragma link off all classes;
#pragma link off all functions;
#pragma link C++ class Node+;

#endif
//---------------------Makefile----------------

ARCH = linux

filename =Node

CXX =
ObjSuf = o
SrcSuf = cxx
ExeSuf =
DllSuf = so
OutPutOpt = -o

ROOTCFLAGS := $(shell root-config --cflags)
ROOTLIBS := $(shell root-config --libs)
ROOTGLIBS := $(shell root-config --glibs)

ifeq ($(ARCH),linux)

Linux with egcs, gcc 2.9x, gcc 3.x (>= RedHat 5.2)

CXX = /usr/bin/g++
CXXFLAGS = -O -Wall -fPIC
LD = /usr/bin/g++
LDFLAGS = -O
SOFLAGS = -shared
endif

ifeq ($(CXX),)
$(error $(ARCH) invalid architecture)
endif

INCLUDES = -I/home/luxg/source/include -I/hermes/pro/writeDST/ddl
CXXFLAGS += $(ROOTCFLAGS)
LIBS = $(ROOTLIBS) $(SYSLIBS) -L/home/luxg/source/lib
GLIBS = $(ROOTGLIBS) $(SYSLIBS)

#------------------------------------------------------------------------------

PARTICLEO = $(filename).$(ObjSuf) $(filename)Dict.$(ObjSuf)
PARTICLES = $(filename).$(SrcSuf) $(filename)Dict.$(SrcSuf)
PARTICLESO = lib$(filename).$(DllSuf)
PARTICLE = $(filename)$(ExeSuf)
PARTICLELIB = $(PARTICLESO)

OBJS = $(PARTICLEO)
PROGRAMS = $(PARTICLE)

#------------------------------------------------------------------------------

.SUFFIXES: .$(SrcSuf) .$(ObjSuf) .$(DllSuf)
.PHONY: Aclock Hello Tetris

$(PARTICLESO): $(PARTICLEO)
$(LD) $(SOFLAGS) $(PARTICLEO) $(OutPutOpt) $(PARTICLESO)
@echo “$@ Successfully Made!!”

clean:
@rm -f $(OBJS) core

distclean: clean
@rm -f $(PROGRAMS) $(PARTICLESO) $(PARTICLELIB) Dict. *.def *.exp
*.root *.ps *.so .def so_locations
@rm -rf cxx_repository

.SUFFIXES: .$(SrcSuf)

$(filename).$(ObjSuf): $(filename).h

$(filename)Dict.$(SrcSuf): $(filename).h $(filename)LinkDef.h
@echo “Generating dictionary $@…”
@rootcint -f $@ -c $^

.$(SrcSuf).$(ObjSuf):
$(CXX) $(CXXFLAGS) -c $<

//------------------------Make----------------
$ make
/usr/bin/g++ -O -Wall -fPIC -pthread -I/home/luxg/root/root-4.04.02g/include -c Node.cxx
Generating dictionary NodeDict.cxx…
/usr/bin/g++ -O -Wall -fPIC -pthread -I/home/luxg/root/root-4.04.02g/include -c NodeDict.cxx
/usr/bin/g++ -shared Node.o NodeDict.o -o libNode.so
libNode.so Successfully Made!!

//-----------------testnode.C-----------------

#include “libNode.so”

typedef Node INode;
testnode()
{

INode a;
}

//-------------------test in ROOT-----------------

$ root
root [0] .x testnode.C
/home/luxg/root/root-4.04.02g/bin/root.exe: error while loading shared libraries: /home/luxg/source/Hermes/decompose/mail/./libNode.so: undefined symbol: __t4Node1Zi

Can somebody help me?

2

Hi,

You need to the implementation of the constructor into the header file. I.e

should be in Node.h

Cheers,
Philippe

3

Hi Philippe,

  Thanks very much!

But it seems that I have to change the code into:
//----------------------------------------
template
inline Node::Node()
{}

other wise, if the code is :
//-----------------------------------------
inline template Node::Node() //L29
{}

an error occurs when I made the library:
//*****************************
$ make
/usr/bin/g++ -O -Wall -fPIC -pthread -I/home/luxg/root/root-4.04.02g/include -c Node.cxx
In file included from Node.cxx:1:
Node.h:29: parse error before `<'
Node.cxx:4: definition provided for explicit instantiation
/home/luxg/root/root-4.04.02g/include/TBuffer.h:63: definition provided for explicit instantiation
/home/luxg/root/root-4.04.02g/include/TBuffer.h:63: non-template used as template
/home/luxg/root/root-4.04.02g/include/TBuffer.h:63: confused by earlier errors, bailing out
make: *** [Node.o] Error 1

Cheers.
Xian-Guo Lu

4

Yes you are right (my mistake :frowning:).

Cheers,
Philippe