This is why I've mentioned io::Write, because people don't chop buffers like that with C-style separately tracked length when they can have zero-copy: html_

This is why I've mentioned io::Write, because people don't chop buffers like that with C-style separately tracked length when they can have zero-copy: html_template.pipe_to(socket); and there's a foolproof io::BufWriter adapter if you need these writes buffered.