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#include <iostream>
#include <vector>
#include <typeinfo>
class Base
{
public:
virtual ~Base();
virtual Base *clone() const = 0;
};
inline Base::~Base()
{}
class Clonable
{
Base *d_bp;
public:
Clonable();
~Clonable();
Clonable(Clonable const &other);
Clonable &operator=(Clonable const &other);
// New for virtual constructions:
Clonable(Base const &bp);
Base &get() const;
private:
void copy(Clonable const &other);
};
inline Clonable::Clonable()
:
d_bp(0)
{}
inline Clonable::~Clonable()
{
delete d_bp;
}
inline Clonable::Clonable(Clonable const &other)
{
copy(other);
}
Clonable &Clonable::operator=(Clonable const &other)
{
if (this != &other)
{
delete d_bp;
copy(other);
}
return *this;
}
// New for virtual constructions:
inline Clonable::Clonable(Base const &bp)
{
d_bp = bp.clone(); // allows initialization from
} // Base and derived objects
inline Base &Clonable::get() const
{
return *d_bp;
}
void Clonable::copy(Clonable const &other)
{
if ((d_bp = other.d_bp))
d_bp = d_bp->clone();
}
class Derived1: public Base
{
public:
~Derived1();
virtual Base *clone() const;
};
inline Derived::~Derived1()
{
std::cout << "~Derived1() called\n";
}
inline Base *Derived::clone() const
{
return new Derived1(*this);
}
using namespace std;
int main()
{
vector<Clonable> bv;
bv.push_back(Derived1());
cout << "==\n";
cout << typeid(bv[0].get()).name() << endl;
cout << "==\n";
vector<Clonable> v2(bv);
cout << typeid(v2[0].get()).name() << endl;
cout << "==\n";
}
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