Можно ли из класса родителя просигналить всем потомкам? - C++ - Ответ 4831126

#include <iostream>
#include <string>
#include <vector>
 
class Base
{
public:
    static void Signal()
    {
        for (std::vector<Base*>::iterator it = _instances.begin() ; it != _instances.end(); ++it)
        {
            (*it)->DoWork();
        }
    }
 
    virtual ~Base()
    {
        for (std::vector<Base*>::iterator it = _instances.begin() ; it != _instances.end(); ++it)
        {
            if (*it == this)
            {
                _instances.erase(it);
                break;
            }
        }
 
        std::cerr << "Calling method \'" << __FUNCTION__ << "\' for object \'" << _name << "\'\n";
    }
    Base(std::string const& name)
    {
        _name = name;
        _instances.push_back(this);
 
        std::cerr << "Calling method \'" << __FUNCTION__ << "\' for object \'" << _name << "\'\n";
    }
    virtual void DoWork()
    {
        std::cerr << "Calling method \'" << __FUNCTION__ << "\' for object \'" << _name << "\'\n";
    }
 
private:
    static std::vector<Base*> _instances;
 
protected:
    std::string _name;
};
std::vector<Base*> Base::_instances;
 
class DerivedA : public Base
{
public:
    virtual ~DerivedA()
    {
        std::cerr << "Calling method \'" << __FUNCTION__ << "\' for object \'" << _name << "\'\n";
    }
    DerivedA(std::string name) : Base(name)
    {
        std::cerr << "Calling method \'" << __FUNCTION__ << "\' for object \'" << _name << "\'\n";
    }
    void DoWork()
    {
        std::cerr << "Calling method \'" << __FUNCTION__ << "\' for object \'" << _name << "\'\n";
    }
};
 
class Derived2A : public DerivedA
{
public:
    virtual ~Derived2A()
    {
        std::cerr << "Calling method \'" << __FUNCTION__ << "\' for object \'" << _name << "\'\n";
    }
    Derived2A(std::string name) : DerivedA(name)
    {
        std::cerr << "Calling method \'" << __FUNCTION__ << "\' for object \'" << _name << "\'\n";
    }
    void DoWork()
    {
        std::cerr << "Calling method \'" << __FUNCTION__ << "\' for object \'" << _name << "\'\n";
    }
};
 
int main()
{
    Base* base = new Base("base");
    DerivedA derivedA("derivedA");
    DerivedA* derived2A = new Derived2A("deriveda2A");
 
    Base::Signal();
 
    delete derived2A;
    delete base;
    return 0;
}