A refresher.

What auto&& means

by Jonathan Boccara

From the article:

Since C++11, we have a && in the language, and it can take some time to understand its meaning and all the consequences this can have on your code.

We’ve been through a detailed explanation of lvalues, rvalues and their references, which covers a lot of ground on this topic.

But there is one aspect that we have to talk about: what does auto&&, X&&, or even int&& means in code...