#ifndef STACK_H_
#define STACK_H_

#include <string>

using Stack_Data = std::string;

class Stack
{
public:
  Stack();
  ~Stack();
  
  Stack(Stack const&) = delete;
  Stack(Stack&&) = delete;
  Stack& operator=(Stack const&) = delete;
  Stack& operator=(Stack&&) = delete;

  bool empty() const;
  void push(Stack_Data const&);
  Stack_Data pop();
  
private:

  class Element
  {
  public:
    Element(Stack_Data const& i, Element* n = nullptr)
      : data(i), next(n) {}
    ~Element() { delete next; }
    
    Element(Element const&) = delete;
    Element(Element&&) = delete;
    
    Element& operator=(Element const&) = delete;
    Element& operator=(Element&&) = delete;
    
    Stack_Data data;
    Element* next;
  };

  Element* first;

};

#endif