Implicit capture of this in lambdas by copy.
std::iterator removed.
std::uncaught_exception() removed.
throw () exception specification removed.
std::strstream, std::istrstream, and std::ostrstream removed.
std::random_shuffle removed.
std::mem_fun and std::mem_fun_ref, std::bind1st and std::bind2nd removed.
There are numerous other things as well, but this is just off the top of my head.
Note too that we are reasonably good (some of us are experts) at C++ and not Rust. Like any other human when we first do Rust we will make a mess because we are trying to do things like C++ - I expect to see too much unsafe just to shut up Rust about things that work in C++ instead of figuring out how to do it in safe rust. (there will also be places where unsafe is really needed) I want to start slow with Rust so that as we learn what works we don't have too much awful code.
C++ has its own Core Guidelines that are pretty rusty already (to be fair, in more ways than one). There's just no automated compiler enforcement of them.
I knew they are bad, but I don't think it should be removed.