C++17 STL Cookbook

Contiguous storage

The simplest way to store objects is to put them just next to each other in one large chunk of memory. Such memory can be accessed in a random access manner in O(1) time.

The easiest way to do that is using std::array, which is just a wrapper around normal C-style arrays. It should always be preferred over normal C-style arrays, because it comes with no runtime cost, but adds some comfort and safety. Just as C-style arrays, it has a fixed size once it is created.

The std::vector comes into play when array-like storage is needed, but with varying sizes. It uses memory from the heap to store objects. Whenever new objects are pushed into the vector exceeding its current size, it will automatically move all items to a larger ...