I'm not really arguing about the value of that code either, just that it's probably wrong, probably trivially breakable due to the sheer mountain of complexity underlying it. The compiler just happened to let it through because it can't help you. The language doesn't give it enough information to do so effectively.

Just off the top of my head, std::move doesn't... move [1]. It just returns an, I kid you not "static_cast<typename remove_reference<T>::type&&>(t)" without doing... anything. You can keep on using the old value probably, silently, until out of the blue, it stops working one day. Then you're super, duper sad. Even modern language features are, I don't want to say lies, but "hopes and dreams" the compiler can't enforce. It's like if you really wished C++ had Rust's features, but you can't without breaking things, so you give it your best shot, which ends up just creating yet more complexity.

Rust's answer is...

  let x = Value::new();
  let y = x;
  let z = x; (COMPILER ERROR: X GOT MOVED INTO Y)

C++'s modern features are to Rust's equivalents what the ruined fresco [2] was to the original. If you stand far enough back, it's basically right. If you get up close it's hilariously and trivially broken.

It takes a lot of gymnastics to call this language approachable or understandable. It's basically a coal powered car made of foot-guns. That doesn't mean it's not a car, or that it won't get you where you're trying to go, I'm just saying it's an open question how many pieces you'll arrive in.

[1] http://yacoder.guru/blog/2015/03/14/cpp-curiosities-std-move...

[2] https://www.npr.org/sections/thetwo-way/2012/09/20/161466361...