Can I create a struct that can only be dynamically allocated?

Question

In C++, can I create a struct that can only be dynamically allocated? I want to enforce a way to make sure that the programmer cannot statically allocate this struct because doing so would lead to a dangling pointer since I need to use the contents of the pointer outside of its scope.

Answer 1

You can make a struct of a private constructor so no one can create from it, then make a friend function that creat a dynamically allocated object and returns a pointer to it, as follows.

#include <iostream>
struct A{
    ~A() {
        std::cout << "\nA has been destructed";
    }
private:
    A(/*args*/) {
        std::cout << "\nA has been created";
    }
    friend A* creatA(/*args*/);

};
A* creatA(/*args*/){
    return new A(/*args*/);
}

int main()
{
    A* ptr = creatA();
    delete ptr;

}

This can be better using smart pointers and @Peter suggestiion

#include <iostream>
#include <memory>

struct A{
    A(/*args*/) {
        std::cout << "\nA has been created";
    }
    friend std::default_delete<A>;
private:
    ~A() {
        std::cout << "\nA has been destructed";
    }
};

int main()
{
    std::unique_ptr<A> ptr = std::make_unique<A>(/*Args*/);

}