如何在boost::variant包装的指针容器中将原始指针更改为unique_ptr

#include <boost/variant.hpp>
#include <boost/ptr_container/ptr_vector.hpp>
#include <memory>

class BaseClass {
public:
    virtual ~BaseClass() {}
    virtual void foo() = 0;
};

class Derived1 : public BaseClass {
public:
    void foo() override {}
};

class Derived2 : public BaseClass {
public:
    void foo() override {}
};

int main() {
    boost::ptr_vector<boost::variant<BaseClass*>> container;

    using VariantType = boost::make_variant_over<boost::mpl::vector<Derived1*, Derived2*>>::type;
    container.push_back(std::unique_ptr<VariantType>(new Derived1()));
    container.push_back(std::unique_ptr<VariantType>(new Derived2()));

    // 使用容器中的指针
    for (auto& item : container) {
        boost::apply_visitor([](auto& ptr) {
            ptr->foo();
        }, item);
    }

    return 0;
}