学习Rust编程——TCP

use std::io::prelude::*;use std::net::TcpStream;fn main() -> std::io::Result<()> {  let mut connection =    TcpStream::connect("www.rustinaction.com:80")?;   connection.write_all(b"GET / HTTP/1.0")?;   connection.write_all(b"\r\n")?;   connection    .write_all(b"Host: www.rustinaction.com")?;   connection.write_all(b"\r\n\r\n")?;   std::io::copy(    &mut connection,    &mut std::io::stdout(),  )?;   Ok(())}