What is the difference between shallow copy and deep copy in memory terms?

A shallow copy copies pointer values, so two objects share the same heap memory—leading to double-free or dangling issues when one is destroyed. A deep copy allocates new memory and copies the pointed-to data, giving each object independent ownership. The Rule of Three/Five ensures correct copy/move semantics for classes managing resources.

// Deep copy in copy constructor
MyClass(const MyClass& o) : data(new int[o.n]), n(o.n) {
    std::copy(o.data, o.data + n, data);
}