Rust means Discipline

Talk on Rust's Reliability, Ownership and Borrow-checker

MYSELF

Source: https://yalantis.com/blog/rust-market-overview/, https://rustmagazine.org/issue-1/2022-review-the-adoption-of-rust-in-business/

Rust is Reliable, C is Not

C's Addition

Rust's Addition

Let's run the code for C & Rust

https://godbolt.org/z/63h8evcrK

Let's run the code for C & Rust

C's assembly

Rust's assembly

C division

Rust division

Let's run the code for C & Rust

https://godbolt.org/z/cPo4o56Yq

Let's run the code for C & Rust

C's assembly (From gcc)

Rust's assembly (From rustc)

Check for zero in denominator

Check for overflow: 128

Check for zero in denominator

Relevant errors are hardcoded into the binary

Rust's Ownership

• Each value in Rust has an owner.
• There can only be one owner at a time.
• When the owner goes out of scope, the value will be dropped.

https://godbolt.org/z/EaTGnan4h

Let's understand why Ownership is required

Ref: https://doc.rust-lang.org/book/ch04-01-what-is-ownership.html

https://godbolt.org/z/h551PGjG1

Ref: https://doc.rust-lang.org/book/ch04-02-references-and-borrowing.html#references-and-borrowing

Let's use references

What is it ?

• References are pointers.
• They never point to invalid memory.
• They never own value.

Mutable references

• Mutable references are simply references that can mutate the data.

https://godbolt.org/z/dnod1oMKK

Borrow-Checker

• Cannot have more than one mutable reference in a scope, if value is accessed.
• Cannot have immutable reference followed by mutable reference, if immutable reference is accessed.
• No dangling references, i.e null pointers.

What is it ?

Two Mutable borrows

Error for borrowing "s" as mutable twice

This is to avoid any

data race conditions

https://www.reddit.com/r/rust/comments/v3vagi/data_races_explanation_in_the_rust_book/

Immutable and mutable borrows

Error for using immutable borrow while mutable borrow is alive

This is to avoid change in value while immutable borrow is still alive

Dangling Pointer

Errors because "s" goes out of scope and there's nothing to reference

This is to avoid any null pointer

Bible: https://doc.rust-lang.org/book/title-page.html

Thank You!

Questions?