Error with Template

Question

Please, could you help me!?

The errors are for all the headers of the.cpp stack file that refers to.h. Involves using Templates.

Battery code. h:

#ifndef PILHA_H
#define PILHA_H

#include <iostream>
//#include <cstdlib>

template <typename T>
class Pilha{

    T * vetor;
    int tam;
    int topo;

public:
    Pilha(int size);
    ~Pilha();

    void Print();
    void Push(T vetor);
    T Pop();
    T Topo();
    void Limpar();

    bool Vazio();
    bool Cheio();

};

#include "pilha.cpp"

#endif

Code of the batteries.cpp:

#include<iostream>
#include "pilha.h"

//Construtor
template <typename T>
Pilha<T>::Pilha(int size){
    vetor = new T[size];
    this->tam = size;
    topo = -1;
}
//Destrutor: remove o vetor completamente
template <typename T>
Pilha<T>:: ~Pilha(){
    delete [] vetor;
    topo = -1;
}
//Inserindo conteúdo:
template <typename T>
void Pilha<T>::Push(T n){
    if(Cheio())
        std:: cout << "Erro: Pilha cheia" << std::endl;
    else
        this->vetor[++topo] = n;
    //topo++;
}
//Removendo conteúdo;
template <typename T>
T Pilha<T>::Pop(){
    T aux = Topo();
    topo--;
    return aux;
}
//Topo da pilha:
template <typename T>
T Pilha<T>::Topo(){
    if(Vazio())
        std::cout << "Erro: Pilha cheia" << std::endl;
    else
        return vetor[topo];
}
//Limpando a pilha:
template <typename T>
void Pilha<T>::Limpar(){
    delete [] vetor;
    topo = -1;  
}
//Pilha vazia:
template <typename T>
bool Pilha<T>::Vazio(){
    if(topo == -1){
        std::cout << "Pilha vazia" << std::endl;
        return true;
    }
    else
        return false;
}
//Pilha cheia:
template <typename T>
bool Pilha<T>::Cheio(){
    if(topo == tam - 1){
        std::cout << "Pilha Cheia" << std::endl;
        return true;
    }
    else
        return false;
}
//Exibindo os elementos da pilha:
template <typename T>
void Pilha<T>::Print(){
    for(int i = topo; i > -1; i--){
        std::cout << vetor[i] << " ";
    }
}

Compilation screen:

Answer 1

The entity definition of a template must be on the same translation unit where it is used. Separation of declaration into headers and definition into translation units does not work with templates.

The reason for this is that the compiler needs to know how the template definition is when it is instantiated. If only the statement is visible at the instance point, the compiler will complain (as seen in your compiler’s error messages. ) And no, there is no way the compiler knows the definition of the declaration of a template that is separated into another translation unit, as there is no information linking one to another (in contrast to normal code, which is not necessary to know the definition of a function to use it.)

With all this said, the solution is to put the settings of your member functions within the header and remove the translation unit.

And finally, you’re including "pilha.cpp" in its header, duplicating the definitions.