unsafety chapter: fill in 5 guidelines

[PLeVasseur]

Work according to the goals outlined in #6

Fill in five guidelines

DRI: @adfernandes

Contributing:

• @vjonaswolf
• @vccjgust
• @pellico

[PLeVasseur]

@adfernandes -- could you post a comment here so that I can assign this to you?

[adfernandes]

Fabulous - thank you, @PLeVasseur!

[adfernandes]

Note to self (and any followers):

Steve Klabnik, very recently on 2025-03-17, wrote a wonderful blog post titled Does unsafe undermine Rust's guarantees?

To quote Steve 🤣:

(The straightforward answer is “no”, by the way.)

To quote The Rustonomicon:

The unsafe keyword has two uses: to declare the existence of contracts the compiler can't check, and to declare that a programmer has checked that these contracts have been upheld.

[PLeVasseur]

Read the article as well. Thanks for sharing it here!

[jmqd]

Hey folks, I was thinking I could write a guideline about the pointer aliasing rules. Before I started work, I wanted to make sure we didn't already have out-of-tree working going on this.