Derive Macro Display

#[derive(Display)]
{
    // Attributes available to this derive:
    #[display]
}

This macros provides the implementation of trait Display (writed for crate add_macro)

Examples:

use add_macro_impl_display::Display;
 
#[derive(Display)]
enum Animals {
    Turtle,
   
    #[display]
    Bird,
    
    #[display = "The Cat"]
    Cat,
 
    #[display("The Dog")]
    Dog,

    Other(&'static str),

    #[display]
    Other2(&'static str),
 
    #[display("{0} {1}, {2} years old")]
    Info(Box<Self>, &'static str, i32),

    #[display("{kind} {name}, {age} years old")] 
    Info2 {
        kind: Box<Self>,
        name: &'static str,
        age: i32,
    },
}

fn main() {
    assert_eq!(format!("{}", Animals::Turtle), "Turtle");
    assert_eq!(format!("{}", Animals::Bird), "Bird");
    assert_eq!(format!("{}", Animals::Cat), "The Cat");
    assert_eq!(format!("{}", Animals::Dog), "The Dog");
    assert_eq!(format!("{}", Animals::Other("Tiger")), "Tiger");
    assert_eq!(format!("{}", Animals::Other2("Tiger")), "Tiger");
    assert_eq!(format!("{}", Animals::Info(Box::new(Animals::Cat), "Tomas", 2)), "The Cat Tomas, 2 years old");
    assert_eq!(format!("{}", 
        Animals::Info2 {
            kind: Box::new(Animals::Cat),
            name: "Tomas",
            age: 2,
        }),
        "The Cat Tomas, 2 years old"
    );
}

use add_macro_impl_display::Display;
 
#[derive(Debug, Display)]
struct Person {
    pub name: String,
    pub age: u8,
    pub email: String,
}
 
#[derive(Debug, Display)]
#[display("Hello, {name}! Your age is {age} years old.{email:.0}")]  // NOTE: if you don't need to use one of field, that use {field_name:.0} syntax
struct PersonInfo {
    pub name: String,
    pub age: u8,
    pub email: String,
}

fn main() {
    assert_eq!(
        format!("{}", Person {
            name: "Bob".to_owned(),
            age: 22,
            email: "bob@example.loc".to_owned()
        }),
        r#"Person { name: "Bob", age: 22, email: "bob@example.loc" }"#
    );
 
    assert_eq!(
        format!("{}", PersonInfo {
            name: "Bob".to_owned(),
            age: 22,
            email: "bob@example.loc".to_owned()
        }),
        "Hello, Bob! Your age is 22 years old."
    );
}