C ++和Netbeans的未定义参考问题

Question

I have the following files:

ListaEnc.hpp

#include "Elemento.hpp"
#include <cstdlib>
#include <iostream>

template<typename T>
class ListaEnc {

public:
    ListaEnc();
    ~ListaEnc();
...
}

//Implementation:
template<typename T>
ListaEnc<T>::ListaEnc()
{
    head = NULL;
    size = 0;
}

template <class T>
ListaEnc<T>::~ListaEnc() {

}

main.cpp:

#include "ListaEnc.hpp"
using namespace std;

int main(int argc, char** argv)
{
    ListaEnc<int>* teste = new ListaEnc<int>();

    return 0;
}

Poligono.hpp

#ifndef POLIGONO_HPP
#define POLIGONO_HPP

#include "Ponto.hpp"
#include "ListaEnc.hpp"
#include <string>

using namespace std;
public:
    //Construtores
    Poligono(ListaEnc<Ponto> pontos, string nome);
    Poligono(const Poligono& orig);
    virtual ~Poligono();

    //Metodos
    string obterNome();
    void adicionarPonto(Ponto);
    ListaEnc<Ponto> obterPontos();
private:
    ListaEnc<Ponto> pontos;
    string nome;
};

#endif  /* POLIGONO_HPP */

Poligono.cpp

#include "Poligono.hpp"



* Poligono::Poligono(ListaEnc<Ponto> pontos, string nome)
{
    this->pontos = pontos;
    this->nome = nome;
}

* Poligono::Poligono(const Poligono& orig) {
}

* Poligono::~Poligono() {
}

//Metodo
string Poligono::obterNome()
{
    return this->nome;
}

ListaEnc<Ponto> Poligono::obterPontos()
{
    return this->pontos;
}

void Poligono::adicionarPonto(Ponto p)
{
    this->pontos.adiciona(p);
}

I get these compile errors on Poligono.cpp:

/home/mariana/NetBeansProjects/TrabalhoCG/Poligono.cpp:12: undefined reference to `ListaEnc::~ListaEnc()'

The destructor for ListaEnc is empty, but is implemented. Does anyone know how to solve this problem?

Edit: Added the implementation of constructor and destructor for ListaEnc. The error appears in the bit of code I added for Poligono.cpp, where ListaEnc is one of the parameters.

Edit2: I have added an asterisk to the points in Poligono.cpp where the error appears (The first constructor, second constructor and destructor)

Answer 1

Since you posted code that shows

#ifndef POLIGONO_HPP
#define POLIGONO_HPP

in Poligono.cpp , but you don't have the same in ListaEnc.hpp , I assume that you are missing include guards in that header?

Depending on what other code is included in Poligono.cpp , this could result in the definition of template ListaEnc twice. Under C++ standard if you break the one definition rule you may just get a linking error and no other diagnostic message.

So, maybe make sure that there are include guards in ListaEnc.hpp ?

If you post more code I will update this answer :)

Edit: Another suggestion, if it is having trouble finding the dtor definition of ListaEnc , you might try moving the implementation of it into the class body? This makes it less likely that a typo will cause it to be lost. Since all the code is in the header this really doesn't change anything otherwise.