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: Fn(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);
}