#include <iostream>
#include <memory>

struct Shape {};

struct Circle : public Shape
{
    Circle()
    {
        std::cout << __PRETTY_FUNCTION__ << '\n';
    }
};

struct Rectangle : public Shape
{
    Rectangle()
    {
        std::cout << __PRETTY_FUNCTION__ << '\n';
    }
};

int main()
{
    for (int i=0; i<5; ++i)
    {
        std::unique_ptr<Shape> sp = (i % 2)
            ? std::unique_ptr<Shape>(new Circle())
            : std::unique_ptr<Shape>(new Rectangle());
    }
    
}