Can you give me examples of using unique_ptr in C++ classes?

Can you give me examples of using unique_ptr in C++ classes?

Sure! A unique_ptr is a smart pointer in C++ that manages the lifetime of an object. Here's a simple example:

#include <iostream>
#include <memory>

class MyClass {
public:
    MyClass() { std::cout << "MyClass created" << std::endl; }
    ~MyClass() { std::cout << "MyClass destroyed" << std::endl; }
};

class Container {
private:
    std::unique_ptr<MyClass> ptr;
public:
    Container() : ptr(std::make_unique<MyClass>()) {}
};

int main() {
    Container c;
    return 0;
}

In this example, Container holds a unique_ptr to MyClass, ensuring that MyClass is automatically destroyed when Container goes out of scope.

What happens if I try to copy a unique_ptr?

If you try to copy a unique_ptr, you'll get a compilation error because unique_ptr is non-copyable. You can only move it. Here's an example:

std::unique_ptr<MyClass> ptr1 = std::make_unique<MyClass>();
std::unique_ptr<MyClass> ptr2 = ptr1; // This will cause a compilation error

Instead, you should use std::move to transfer ownership:

std::unique_ptr<MyClass> ptr2 = std::move(ptr1); // This is valid

Can unique_ptr be used with arrays?

Yes, unique_ptr can manage arrays as well. You can use std::unique_ptr<Type[]> for that. Here's an example:

std::unique_ptr<int[]> arr = std::make_unique<int[]>(10); // array of 10 integers