The details of a processor's handling of memory is both complicated and very specific to that processor. Programming languages—and Rust is no exception here—invent a memory model to paper over the details of all supported processors while, ideally, leaving the programmer enough freedom to exploit the specifics of each processor. Systems languages also tend to allow absolute freedom in the form of escape hatches from the language memory model, which is exactly what Rust has in terms of unsafe.
With regard to its memory model, Rust is very much inspired by C++. The atomic orderings exposed in Rust are those of LLVM's, which are those of C++11. This is a fine thing—any literature to do with either C++ or LLVM will be immediately ...
