Rust superficially looks like C++ to avoid looking weird to existing C/C++ programmers, but semantically it's quite far from C++. Rust's generics are not like C++ templates: they're only type based, and don't use syntax-based matching, don't have tricks like SFINAE. ODR is guaranteed by construction. Trait lookup is simpler: there's no overloading, no inheritance, no implicit conversions, and interaction with namespaces is simple (ambiguity is an error).
Phantom type looks alien if you haven't used it, but for what it does, it's actually a pretty simple. It's there to explain in Rust's terms what an opaque type or a foreign C/C++ type does. You just need to give Rust an example of an equivalent type, and you get a correct as-if behavior, and you don't need to even know that you've just configured type's variance and destruction order checking.
Phantom type looks alien if you haven't used it, but for what it does, it's actually a pretty simple. It's there to explain in Rust's terms what an opaque type or a foreign C/C++ type does. You just need to give Rust an example of an equivalent type, and you get a correct as-if behavior, and you don't need to even know that you've just configured type's variance and destruction order checking.