[kamac]

I forgot to add "mostly scarcely useful", instead of "scarcely useful". There are some things that make sense, like file system library and async I/O library that you've mentioned (althrough I don't agree on concepts and modules, but that's up to one's preference), but then comes stuff like constexpr, rvalue reference, Deleted and Defaulted Functions, that aren't essential to most programmers, and mostly just clutter the language, because only like, 1% will use them, and the rest will be like "what the hell is this" when looking at that 1%'s code.

[sseagull]

I disagree. I'm a scientific programmer working mainly in C++ and Python. Deleted and defaulted functions help a lot by reducing the amount of code that needs to be written, maintained, and debugged. Rvalue references help by reducing unnecessary copying, which is a huge benefit when working with large data structures. Before, the workaround was classes that wrapped pointers with shallow copy semantics, which turns into an aliasing nightmare.

YMMV, depending on your field, of course.