macro_rules! tuple_map {
    ($f:expr, $($e:expr),*) => {($($f($e)),*)}
}

fn main() {
   let mut words = "I want to make f and g into chars".split_whitespace();
   if let (Some(first), Some(second)) = (words.nth(4), words.nth(1)) {
       let (f,s) = tuple_map!( |c:&str| c.parse::<char>().unwrap(), first, second);
       dbg!((f, s));
   }
}