first code in Rust

Today I woke up with a thought: learn Rust. I bought a book about 3 months ago and I started to read it, read code on GitHub etc but I never wrote a code by myself. After 1 hour (yeah, I suck) I implemented a fibonacci sequence. I think I used every Rust tips, but idk.

kinda suck

This is the bad code I wrote but I'm very proud of it.

use std::mem;

fn fib(n: &mut i32) -> i32 {
    let mut a = 1;
    let mut b = 1;
    while *n > 1 {
        a += b;
        mem::swap(&mut a, &mut b);
        *n -= 1;


This prints the first \(N\) numbers from the fibonacci code.

println!("{}", fib(&mut N));

Maybe one day I'll look at this code and think:"WTF is that?!".

Written on April 13, 2020