Objects in memory

All the objects we use in a C++ program reside in memory. Here, we will explore how objects are created and deleted from memory and also describe how objects are laid out in memory.

Creating and deleting objects

In this section, we will dig into the details of using new and delete. We are all familiar with the standard way of using new for creating an object on the free store and then deleting it using delete:

auto user = new User{"John"};  // allocate and construct 
user->print_name();            // use object 
delete user;                   // destruct and deallocate

As the comments suggest, new actually does two things:

1. Allocates memory to hold a new object of the User type
2. Constructs a new User object in the allocated memory space by calling the constructor of the User class

The same thing goes with delete:

1. Destructs the User object by calling its destructor
2. Deallocates/frees the memory that the User object was placed in

Placement new

C++ allows us to separate memory allocation...