Using unique_ptr to uniquely own a memory resource

Manual handling of heap memory allocation and releasing is one of the most controversial features of C++. All allocations must be properly paired with a corresponding delete operation in the correct scope. If the scope of memory allocation is a function, for instance, and memory needs to be released before the function returns, then this has to happen on all the return paths, including the abnormal situation where a function returns because of an exception. C++11 features, such as rvalues and move semantics, have enabled the development of smart pointers; these pointers can manage a memory resource and automatically release it when the smart pointer is destroyed. In this recipe, we will look at std::unique_ptr: a smart pointer that owns and manages another object or an array of objects allocated on the heap and performs the disposal operation when the smart...