nayantha / rectangles_with_rust

This code base developed on the concept of struct in RUST language and use rectangle as the primary object of struct example. Contain struct define, implementing methods, printing struct structures. Tutorial is from: “No.Starch.Press.The.Rust.Programming.Language”

title	slug	excerpt	date	author
Struct in Rust	struct-in-rust	Explain the struct in Rust. Rectangle is used to demonstrate the behaviour of the struct.	09.10.23	Nayantha Yasiru

Struct in Rust

Rectangle is used to Demonstrate

Define Struct

#[derive(Debug)] can be used to easily print struct on the output / CMD.
{:?} - list all the values in single line
{:#?} - format the struct (similar to json format)

struct Rectangle {
    width: u32, // fields
    height: u32,
}

Implement Methods

impl Rectangle {
    fn area(&self) -> u32 { // self is calling itself
        self.width * self.height
    }
    fn can_hold(&self, rect: &Rectangle) -> bool {
        self.area() >= rect.area() && (
            (self.width >= rect.width && self.height >= rect.height) ||
                (self.width >= rect.height && self.height >= rect.width)
        )
    }
    fn make_square(size: u32) -> Rectangle { // associated method - not calling self method
        Rectangle { width: size, height: size }
    }
}

Struct Tips

Struct Construct
Normal

fn build_user(email: String, username: String) -> User {
    User {
        email: email,
        username: username,
        active: true,
        sign_in_count: 1,
    }
}

Simple & Fast Way

fn build_user(email: String, username: String) -> User {
    User {
        email,
        username,
        active: true,
        sign_in_count: 1,
    }
}

Constuct from another struct - Normal

let user2 = User {
    email: String::from("[email protected]"),
    username: String::from("anotherusername567"),
    active: user1.active,
    sign_in_count: user1.sign_in_count,
};

Simple & Fast Way

let user2 = User {
    email: String::from("[email protected]"),
    username: String::from("anotherusername567"),
    ..user1
};