Memory Management in Depth

Beyond new/delete and smart pointers, C++ exposes finer control when it's genuinely needed. Placement new constructs an object at a specific, already-allocated address, skipping the allocation step:

#include <new>

alignas(int) char buffer[sizeof(int)];
int *p = new (buffer) int(42); // construct AT buffer's address
p->~int();                       // must destroy manually — no delete

This is a specialized tool — used inside custom allocators, memory pools, and some embedded contexts — not something everyday C++ code reaches for. For the overwhelming majority of code, std::vector, std::make_unique, and the STL containers already covered are the right level of abstraction.