What are some advanced examples of using unique_ptr in C++?

What are some advanced examples of using unique_ptr in C++?

Unique pointers are a smart pointer type in C++ that manage dynamic memory. One advanced example is using unique_ptr with custom deleters.

Can you show me how to implement a unique_ptr with a custom deleter?

Sure! Here's an example:

#include <iostream>
#include <memory>

struct CustomDeleter {
    void operator()(int* p) {
        std::cout << "Deleting pointer: " << *p << '\n';
        delete p;
    }
};

int main() {
    std::unique_ptr<int, CustomDeleter> ptr(new int(42));
    return 0;
}

This will call the custom deleter when the unique_ptr goes out of scope.

What happens if I try to copy a unique_ptr?

You cannot copy a unique_ptr because it is designed to have sole ownership of the resource. If you try to copy it, you'll get a compilation error. You can, however, move it using std::move().

Can you explain the difference between unique_ptr and shared_ptr?

Certainly! unique_ptr provides exclusive ownership of a resource, while shared_ptr allows multiple pointers to share ownership of the same resource. This means that shared_ptr keeps a reference count to manage the resource's lifetime.