#include <iostream>
#include <memory>
class Base {
private:
int _v1;
public:
Base(int v) : _v1(v)
{ std::cout << "Base::Ctor " << std::endl;}
virtual int GetVal() {
std::cout << "Base::GetVal() \t";
return _v1;
}
};
class Derived : public Base {
private:
int _v1;
public:
Derived(int v) : Base(v), _v1(v)
{ std::cout << "Derived::Ctor " << std::endl; }
int GetVal() override{
std::cout << "Derived::GetVal() \t";
return _v1;
}
};
// Pass by Value
int GetDerived3(std::unique_ptr<Base> ptr)
{
std::cout << "GetDerived3()\t"
<< "ptr.get() " << ptr.get()
<< " " << ptr->GetVal() << std::endl;
return 1;
}
// Pass by reference
int GetDerived4(std::unique_ptr<Base> & ptr)
{
std::cout << "GetDerived4()\t"
<< ptr->GetVal() << std::endl;
return 1;
}
int main()
{
auto a = std::make_unique<Derived>(23);
std::cout << "main() a \t"
<< "a.get() " << a.get() << std::endl;
GetDerived3(std::move(a));
//GetDerived4(a);
std::cout << "After move in main() a \t"
<< "a.get() " << a.get() << "\n\n";
std::unique_ptr<Base> b = std::make_unique<Derived>(24);
std::cout << "main() b \t"
<< "b.get() " << b.get()
<< " " << b->GetVal() << std::endl;
GetDerived4(b);
std::cout << "After passing to GetDerived4\t"
<< "b.get() " << b.get()
<< " " << b->GetVal() << std::endl;
return 1;
}
