Code shared from the Rust Playground

playground.rs

use std::collections::HashMap;

pub struct Selector {
    pub networks: HashMap<u32, Vec<&'static str>>,
}

impl Selector {

    pub fn new() -> Selector {
        Selector {
            networks: [
                (0,      vec!["0.0.0.0/0"]),
                (1918,   vec!["10.0.0.0/8", "192.168.0.0/16"]),
                (1337,   vec!["8.8.8.8/32"]),
                      ].iter().cloned().collect()
        }
    }
    
    pub fn get_generation(&self, x: u32) -> Vec<&'static str>
    {
        let default = vec!["128.200.0.0/16", "1.2.3.0/24"];
        match self.networks.get(&x) {
            Some(n) => n.to_owned(),
            None => {
                // Log here if you want ...
                default
            }
        }
    }
}

fn main() {

    let dd = Selector::new();
    let ip_list = dd.get_generation(1919);

    println!("{:?}", ip_list);
}