Building template Stack structure with vector c++ - c++

Question

I am realizing a templated Stack structure on the base of vector in C++. I am not sure what is wrong with my code.
Stack.h
#ifndef STACK_H_
#define STACK_H_
#include <vector>
using namespace std;
template <class T>
class Stack {
public:
Stack();
virtual ~Stack();
bool empty();
int size();
void push(T pushvar);
T pop();
private:
std::vector<T> container;
};
#endif /* STACK_H_ */
Stack.cpp
#include "Stack.h"
#include <vector>
//template <class T>
Stack::Stack()
:container(0)
{
}
Stack::~Stack() {
// TODO Auto-generated destructor stub
}
bool Stack::empty(){
return (container.empty());
}
Even before calling anything from the main, Eclipse gives me several errors. But I will give an exemplary main:
#include <iostream>
#include "Stack.cpp"
using namespace std;
int main() {
Stack<int> s;
cout << s.empty();
return (0);
}
The compiler returns the following errors:
Description Resource Path Location Type
'container' was not declared in this scope Stack.cpp /PracticeCpp/src line 23 C/C++ Problem
'template<class T> class Stack' used without template parameters Stack.cpp /PracticeCpp/src line 22 C/C++ Problem
invalid use of template-name 'Stack' without an argument list Stack.cpp /PracticeCpp/src line 12 C/C++ Problem
invalid use of template-name 'Stack' without an argument list Stack.cpp /PracticeCpp/src line 18 C/C++ Problem
Member declaration not found Stack.cpp /PracticeCpp/src line 12 Semantic Error
Member declaration not found Stack.cpp /PracticeCpp/src line 18 Semantic Error
Member declaration not found Stack.cpp /PracticeCpp/src line 22 Semantic Error
Method 'empty' could not be resolved Stack.cpp /PracticeCpp/src line 23 Semantic Error
Symbol 'container' could not be resolved Stack.cpp /PracticeCpp/src line 13 Semantic Error
I know that I haven't realized all the methods declared in the header file, but this is not my problem. Before I continue realizing them I want to understand where am I wrong?
Correction after the answers:
I followed the suggestions in the answers but still I don't get what continues to be wrong. I moved the template realizations to the header. I deleted the other unrealized methods to avoid confusion. Now my .cpp file is empty.
My new header file:
#ifndef STACK_H_
#define STACK_H_
#include <vector>
template <class T>
class Stack {
private:
std::vector<T> container;
public:
template <typename T>
Stack<T>::Stack() : container(0)
{
}
template <class T>
bool Stack::empty() {
return container.empty();
}
};
#endif /* STACK_H_ */

Answer 1

definition should be
template <typename T>
Stack<T>::Stack() : container(0)
{
}
And not in .cpp

Answer 2

The method Stack::empty() was never declared, you declared Stack<T>::empty(). The same is true for each other constructor, operator and method. Add a template declaration to each implementation to fix this error. Notice that the error message hints at the mistake by saying "invalid use of template-name 'Stack' without an argument list".
Example :
template<class T> bool Stack<T>::empty() {
return container.empty();
}
Implementations for template methods should be included in header files. See this question.
Edit :
Regarding your newest example, you've mixed up two solutions. Try either :
#include <vector>
template <class T>
class Stack {
private:
std::vector<T> container;
public:
Stack() : container(0)
{
}
bool empty() {
return container.empty();
}
};
OR
#include <vector>
template <class T>
class Stack {
private:
std::vector<T> container;
public:
Stack();
bool empty();
};
template<class T>
Stack<T>::Stack() : container(0)
{
}
template<class T>
bool Stack<T>::empty()
{
return container.empty();
}
In the first solution, you are defining your functions within the definition of your class. The compiler knows that you are working on class Stack<T>, you mustn't remind it. In the second solution, the functions are defined outside the class. Here, you must specify which class' empty method and constructor you are defining.