pub struct Log {
    data: Vec<u8>
}

pub struct Event {
    whatever: u8
}

pub fn test<F, T>(v: Vec<Log>, func: F) -> Vec<T>
where F: FnOnce(Vec<u8>) -> T
{
    v.into_iter().map(|l| {
        let data = l.data;
        func(data)
    }).collect()
}

fn to_string(data: Vec<u8>) -> Event {
    Event {
        whatever: data[0]
    }
}

fn main() {
    let l1 = Log { data: vec![1, 2, 3, 4, 5] };
    let l2 = Log { data: vec![1, 2, 3, 4, 5] };
    test(vec![l1, l2], to_string);
}