struct Context {
    t: Option<i32>,
}

impl Context {
    fn new() -> Context {
        Context {t:None}
    }

    fn init(&mut self) {
        self.t = Some(12);
    }
}

thread_local! {
    static CONTEXT: Context = Context::new();
}

fn main() {
    CONTEXT.with(|c| {
        c.init();
    });

    CONTEXT.with(|c| println!("{}", c.t.unwrap()));
}