Sort of, Rust is supposed to make references to packed structure members unsafe, but currently doesn't. An RFC was accepted to change the behavior but it has not been fully implemented. Here's the tracking issue: https://github.com/rust-lang/rust/issues/27060
Considering dereferencing a pointer after doing some arithmetic on it can only be done within unsafe blocks, I would say you are at least warned about it. But it will happily compile.
Comments
Could Rust's typesystem catch unaligned pointer dereferences?
Sort of, Rust is supposed to make references to packed structure members unsafe, but currently doesn't. An RFC was accepted to change the behavior but it has not been fully implemented. Here's the tracking issue: https://github.com/rust-lang/rust/issues/27060
Considering dereferencing a pointer after doing some arithmetic on it can only be done within unsafe blocks, I would say you are at least warned about it. But it will happily compile.