type CustomError = &'static str;
type Result<T> = std::result::Result<T, CustomError>;

fn main() -> Result<()> {
    let val = vec![Ok(1), Ok(2),Err("Some error")];
    let res: Vec<i32> = val.into_iter().collect::<Result<_>>()?; // Error: "Some error"

    println!("{:?}", res);

    Ok(())
}