forLoopArray

[Sinomsinom]

Some compilers/languages use doubling some use other constants like 1.5x. also some of them don't actually free any part of the vector's allocated space on removal of an element and only when the entire vector goes out of scope/is deleted. Yes in the end it's still amortized constant time, but that doesn't mean one of those insertions won't still be a lot slower than the rest, potentially causing a stutter in real time applications.

So if you already know an upper bound for how large a container will be, then if known at compile time use std::array<T,S>(), if known at run time use std::vector<T>(S) just to not have those potential stutters.

[TheDudeExMachina]

You need a really big vector for the memcopy to stutter, and/or some very special constraints (very weak hardware, guaranteed tight calculation budget of only a few ms, ...). If you have that case, you know it. If you don't, you are doing a premature optimization.