#![allow(dead_code)] #![warn(clippy::unused_io_amount)] use std::io; fn question_mark<T: io::Read + io::Write>(s: &mut T) -> io::Result<()> { s.write(b"test")?; let mut buf = [0u8; 4]; s.read(&mut buf)?; Ok(()) } fn unwrap<T: io::Read + io::Write>(s: &mut T) { s.write(b"test").unwrap(); let mut buf = [0u8; 4]; s.read(&mut buf).unwrap(); } fn vectored<T: io::Read + io::Write>(s: &mut T) -> io::Result<()> { s.read_vectored(&mut [io::IoSliceMut::new(&mut [])])?; s.write_vectored(&[io::IoSlice::new(&[])])?; Ok(()) } fn main() {}