IPlugin.h

#pragma once

#include <iostream>

class IPlugin
{
public:
  virtual void doSth() = 0; // muss implementiert werden
  
  virtual void otherToDo()
  {
    std::cout << "default impl called" << std::endl;
  }
};

main.cpp

#include "IPlugin.h" // eig nicht nötig
#include "MyPlugin.h"
#include "MyOtherPlugin.h"

#include <vector>
#include <memory> // smart pointer

int main()
{
  std::vector<std::shared_ptr<IPlugin>> plugins;
  plugins.emplace_back(std::make_shared<MyPlugin>());
  plugins.emplace_back(std::make_shared<MyOtherPlugin>());
  
  for (auto *plugin : plugins) {
    plugin->doSth();
    plugin->otherToDo();
  }
  
  // jetzt kümmert sich vector destructor um das aufräumen der shared_ptr und der shared_ptr kümmert sich ums aufräumen der Plugin Objekte
}

MyOtherPlugin.h

#pragma once

#include "IPlugin.h"

#include <iostream>

class MyOtherPlugin : public IPlugin
{
public:
  void doSth() override
  {
    std::cout << "work work work" << std::endl;
  }
};

MyPlugin.h

#pragma once

#include "IPlugin.h"

#include <iostream>

class MyPlugin : public IPlugin
{
public:
  void doSth() override
  {
    std::cout << "i should so something..." << std::endl;
  }
  
  void otherToDo() override
  {
    std::cout << "I am special" << std::cout;
  }
};