# Stjepan - Blocking Inside Async Code (Highlights)  ## Highlights - Blocking is everywhere - Consider **standard input** and **output**. It’s pretty obvious that reading from the standard input blocks and you shouldn’t use `std::io::Stdin` inside async code. But would you raise a brow if you saw `println!()` there? I bet we all most of the time assume printing to standard output does not block while it really could.