TIL that in #rust you can do ... my_vec .iter() .map(|x| something_returning_result(x)) .collect::<Result<Vec<_>>()?; (also works with Option<Vec<_>>!) How could I have missed this omg. (;´༎ຶٹ༎ຶ`) Now I finally also understand why type inference is so funky around .collect() :) https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.collect