Copy and Move Semantics

• Copy constructor T(const T&) — makes an independent copy.
• Move constructor T(T&&) — steals the resources of a temporary instead of copying them (much faster for big buffers).

std::vector<int> a(1'000'000);
std::vector<int> b = a;              // copy: 1M elements duplicated
std::vector<int> c = std::move(a);   // move: c takes a's buffer, a is left empty

Rule of five: if your class manages a resource and defines a destructor, copy constructor/assignment or move constructor/assignment, it probably needs all five. Better still, use standard types (std::vector, std::unique_ptr) and write none (rule of zero).