global.rs

use std::cell::RefCell;
use std::mem;

struct Foo {
    bar: String
}

thread_local!(static LOOKUP: RefCell<Option<Vec<Foo>>> = RefCell::new(None));

fn lookup<'a>(idx: usize) -> Option<&'static str> {
    LOOKUP.with(|slot| {
        match *slot.borrow() {
            None => panic!("init lookup first"),
            Some(v) => Some(v[idx].bar.as_slice())
        }
    })
}

fn set(vs: Vec<Foo>) {
    LOOKUP.with(|slot| {
        *slot.borrow_mut() = Some(vs);
    })
}

fn main() {
    let vs = vec![Foo { bar: "foobar".to_string() }];
    set(vs);
}