Option into Result

The Option method ok_or can be used to unwrap an Option if it is some, or convert it to an Err if it is None.

fn try_get_element<T: Copy>(vec: &Vec<T>, index: usize) -> Result<T, String> {
    Ok(*vec.get(index).ok_or("whoops not found")?)
}

There is also ok_or_else which accepts a closure to convert into an Err.