unique_ptr

The Covariant Return Type of a member function allows an overriding member function to return a narrower type. This is particularly useful when you implement the Prototype Pattern.

A std::unique_ptr manages automatically and exclusively the lifetime of its resource according to the RAII idiom. std::unique_ptr should be your first choice because it does its work without memory or performance overhead.

C++11 offers four different smart pointers. On two of them, I will have a closer look in this post regarding memory and performance overhead. My first candidate std::unique_ptr takes exclusively care of the lifetime of one resource; std::shared_ptr shares the ownership of a resource with other std::shared_ptr's. I will state the result of my tests before I show you the raw numbers: There are only a few reasons in modern C++ justifying the memory management with new and delete.