Undefined symbols for architecture x86_64:
  "Person::~Person()", referenced from:
      Teacher::~Teacher() in test-9423bf.o
      Student::~Student() in test-9423bf.o
ld: symbol(s) not found for architecture x86_64

#include <iostream>
#include <vector>
#include <memory>

class Person {
public:
    virtual void printName() = 0;
    virtual ~Person() = 0;
};

class Teacher : public Person {
public:
    void printName() {
        std::cout << "Hello My Name is Teacher" << std::endl;
    }
    ~Teacher() {}

};

class Student : public Person {
public:
    void printName() {
        std::cout << "Hello My Name Is Student" << std::endl;
    }

    ~Student() {}

};

//Capturing the raw pointer and letting it go out of scope
template<typename Person, typename Teacher>
std::unique_ptr<Person> static_unique_pointer_cast (std::unique_ptr<Teacher>&& old){
    return std::unique_ptr<Person>{static_cast<Person*>(old.release())};
    //conversion: unique_ptr<FROM>->FROM*->TO*->unique_ptr<TO>
}

auto main() -> int {


    auto t1 = std::make_unique<Teacher>();
    auto t2 = std::make_unique<Teacher>();
    auto t3 = std::make_unique<Teacher>();

    auto s1 = std::make_unique<Student>();
    auto s2 = std::make_unique<Student>();
    auto s3 = std::make_unique<Student>();

    std::vector<std::unique_ptr<Person>> v;
    // v.push_back(static_unique_pointer_cast<Person>(std::move(s1)));

    auto foo = static_unique_pointer_cast<Person>(std::move(s1));
    // std::vector<std::unique_ptr<Person>> ve = {
    //     std::move(t1),
    //     std::move(t2),
    //     std::move(t3),
    //     std::move(s1),
    //     std::move(s2),
    //     std::move(s3)
    //     };

    return 0;
}