Reading memory the unsafe way

unsafe is a concept in Rust where some compiler safety mechanisms are turned off. These superpowers bring Rust closer to C's abilities to manipulate (almost) arbitrary parts of the memory. unsafe itself qualifies a scope (or function) to be able to use these four superpowers (from https://doc.rust-lang.org/book/ch19-01-unsafe-rust.html ):

• Dereference a raw pointer.
• Call an unsafe function or method.
• Access or modify a mutable static variable.
• Implement an unsafe trait.

In most projects, unsafe is only required for using the FFI (short for Foreign Function Interface) because it's outside of the borrow checker's reach. Regardless, in this recipe, we are going to explore some unsafe ways to read memory.