// use std::io::{self, Write};

#![allow(dead_code)]
#![allow(unused)]

mod errors;
mod option;

use errors::nov7;
use option::okt31;

#[derive(Debug)]
struct Kreis {
    r: f32,
    name: String,
}

#[derive(Debug)]
enum Farbe {
    Rot,
    Gruen,
    Blau,
}

fn main() {
    // okt24();
    // okt31();
    let r = nov7();
    // println!("r = {r}");
}

fn okt24() {
    let a: [i32; 4] = [4, 3, 9, 1];
    let mut i: usize = 0;
    // for i in a { ... }
    while i < 4 {
        println!("{}", a[i]);
        i += 1;
    }

    let b = a;
    println!("{b:?}");

    let k = Kreis {
        r: 1.0,
        name: String::from("Kreis 1"),
    };
    println!("{k:?}");

    println!("{:?}", Farbe::Rot);

    let mut m = k;
    // let _b = &m; // _b borgt sich m
    // println!("{k:?}");
    println!("{m:?}");

    m = f1(m);
    println!("<2> {m:?}");

    f2(&mut m);
    println!("<5> {m:?}");

    let r1 = &mut m;
    r1.r = 3.0;

    println!("<6> {r1:?}");

    /*
    let mut r2 = &mut m;
    r2.r = 4.0;

    println!("<7> {r2:?}");

    println!("<8> {r1:?} {r2:?}");
    */

    let x = f3();
    println!("<3> {x}");

    // f4(); /* geht nicht */
}

fn f1(a: Kreis) -> Kreis {
    println!("<1> {a:?}");
    a
}

fn f2(p: &mut Kreis) {
    p.r = 2.0;
    println!("<4> {p:?}");
}

fn f3() -> i32 {
    if false { 14 } else { 23 }
}

/* -- geht nicht --
fn f4() -> &'static Kreis {
     let k = Kreis { r: 5.0, name = "Hallo".into() };
     &k
}
*/