Scoped pool lifetime problems

extern crate scoped_threadpool;
use scoped_threadpool::{Pool, Scope};

#[derive(Debug)]
pub struct RefOwner<'a>(&'a str);

pub struct ScopeRef<'pool, 'scope> where 'pool: 'scope {
    scope: &'scope Scope<'pool, 'scope>,
}

impl<'pool, 'scope> ScopeRef<'pool, 'scope> {
    pub fn new(scope: &'scope Scope<'pool, 'scope>) -> ScopeRef<'pool, 'scope> {
        ScopeRef { scope: scope }
    }

    pub fn execute(&self, ref_owner: &'scope RefOwner) -> String {
        self.scope.execute(move || {
            println!("Got: {:?}", ref_owner);
        });
        ref_owner.0.to_owned()
    }
}

#[test]
fn it_works() {
    let foo = "foo".to_owned();
    let mut pool = Pool::new(2);

    pool.scoped(|scope| {
        let scope_ref = ScopeRef::new(scope);
        let result = scope_ref.execute(&RefOwner(&foo));
        assert_eq!(foo, result);
    });
}



src/lib.rs:35:43: 35:48 error: cannot infer an appropriate lifetime for automatic coercion due to conflicting requirements [E0495]
src/lib.rs:35         let scope_ref = ScopeRef { scope: scope };
                                                        ^~~~~
src/lib.rs:35:43: 35:48 note: first, the lifetime cannot outlive the expression at 35:42...
src/lib.rs:35         let scope_ref = ScopeRef { scope: scope };
                                                        ^~~~~
src/lib.rs:35:43: 35:48 note: ...so that auto-reference is valid at the time of borrow
src/lib.rs:35         let scope_ref = ScopeRef { scope: scope };
                                                        ^~~~~
src/lib.rs:31:25: 40:6 note: but, the lifetime must be valid for the anonymous lifetime #1 defined on the block at 31:24...
src/lib.rs:31     pool.scoped(|scope| {
src/lib.rs:32         /*
src/lib.rs:33         let scope_ref = ScopeRef::new(scope);
src/lib.rs:34         */
src/lib.rs:35         let scope_ref = ScopeRef { scope: scope };
src/lib.rs:36         /*
              ...
src/lib.rs:31:23: 31:24 note: ...so that the reference type `&scoped_threadpool::Scope<'_, '_>` does not outlive the data it points at
src/lib.rs:31     pool.scoped(|scope| {
                                    ^