6. Structs and Methods

structs_methods.md

6. Structs and Methods

• Struct types
• Tuple Structs
• Methods and their use
• Private and public data, access rules

Struct definitions

#[derive(Debug)]
struct S {
    id : u64,
    name : String,
}

fn main() {
    let s : S = S{
        id : 12,
        name : "Mustermann".to_string(),
    };
    println!("{:?} {} {}", s, s.id, s.name);
}

Tuple Structs

#[derive(Debug)]
struct S(u64, String);

#[derive(Debug)]
struct U;

fn main() {
    let s : S = S(12, "Mustermann".to_string());
    let u : U = U;
    println!("{:?} {} {} {:?}", s, s.0, s.1, u);
}

Methods

#[derive(Debug)]
struct S {
    id : u64,
    name : String,
}

impl S {
    fn new(c : u64, s : &str) -> S {
        S{id: c, name: s.to_string()}
    }
    fn show(&self) {
        println!("S: id={} name={}", self.id, self.name);
    }
    fn inc(&mut self) {
        self.id += 1;
    }
}

fn main() {
    let s : S = S{
        id : 12,
        name : "Mustermann".to_string(),
    };
    let mut s2 = S::new(1u64, "Mueller");
    s2.inc();
    s2.show();

    println!("{:?} {} {} {:?}", s, s.id, s.name, s2);
}

Private and public data

mod m {
    #[derive(Debug)]
    pub struct S {
        pub id : u64,
        name : String,
    }

    impl S {
        pub fn new(c : u64, s : &str) -> S {
            S{id: c, name: s.to_string()}
        }
        pub fn show(&self) {
            println!("S: id={} name={}", self.id, self.name);
        }
        pub fn inc(&mut self) {
            self.id += 1;
        }
    }
}

fn main() {
    let mut s = m::S::new(1u64, "Mueller");
    s.inc();
    s.show();

    println!("{:?} {}", s, s.id);
}

References:

• Rust book: https://doc.rust-lang.org/book/ch05-00-structs.html
• Video: https://youtu.be/G1b2k49DtVs
• Overview: https://gist.github.com/max-itzpapalotl/18f7675a60f6f9603250367bcb63992e