Here's an example I put together demonstrating this: https://play.rust-lang.org/?version=stable&mode=debug&editio...
Move constructors are one of the worst parts of C++ and being able to write movable, intrusive data structures is absolutely not worth the cost. If you do need one, Rust shows that it's better to sacrifice movability than introduce move constructors.
This is not uncommon -- there are some things you can do in C++ that you simply cannot do in Rust (either safely, or at all). Usually there's another, better way to achieve the same overall goals.
Move constructors fix a narrow problem, which is, when you have something like a vector append, how do you copy over all the previous elements as a "shallow" copy rather than a deep one?
In C with realloc(), it's just assumed that memcpy works for that. With C++03 and earlier copying the elements could very well end up duplicating everything on the heap for no reason, then discarding the old copy.
How does rust do this? What I am reading from googling is that every assignment is a move?
Since Rust always enforces that a move is a memcpy, a vector reallocation is just a realloc() like in C.
Also, Pin is stable but async/await is not, so you’re backwards there :)
