What are the best practices for using unique pointers in C++?

What are the best practices for using unique pointers in C++?

When using unique pointers in C++, it's important to ensure proper ownership and avoid memory leaks. Here are some best practices:

1. Use std::make_unique to create unique pointers, as it helps prevent memory leaks and is more efficient.
2. Avoid using raw pointers; always prefer unique pointers for resource management.
3. Be cautious with transferring ownership using std::move to avoid dangling pointers.

Can you explain why std::make_unique is preferred?

std::make_unique is preferred because it simplifies memory management by ensuring that the memory is allocated and the unique pointer is created in a single step. This reduces the risk of memory leaks and exceptions during allocation, making your code safer and cleaner.

What happens if I forget to use std::move when transferring ownership?

If you forget to use std::move, the unique pointer will still hold the original resource, and you'll end up with two unique pointers pointing to the same resource. This will lead to a double deletion error when both pointers go out of scope, causing undefined behavior.

Are there any situations where using unique pointers is not recommended?

Yes, unique pointers are not recommended in situations where shared ownership is required. In such cases, consider using std::shared_ptr instead. Additionally, avoid using unique pointers for objects that need to be stored in standard containers that require copyable elements.