chore: Fix examples not working with `cargo run` (#998)

* chore: Fix examples not working with `cargo run`

## Motivation

PR #991 moved the `tokio` crate to its own subdirectory, but did not
move the `examples` directory into `tokio/examples`. While attempting to
use the examples for testing another change, I noticed that #991 had
broken the ability to use `cargo run`, as the examples were no longer
considered part of a crate that cargo was aware of:

```
tokio on master [$] via 🦀v1.33.0 at ☸️ aks-eliza-dev
➜  cargo run --example chat
error: no example target named `chat`

Did you mean `echo`?
```

## Solution

This branch moves the examples into the `tokio` directory, so cargo is
now once again aware of them:

```
tokio on eliza/fix-examples [$] via 🦀v1.33.0 at ☸️ aks-eliza-dev
➜  cargo run --example chat
   Compiling tokio-executor v0.1.7 (/Users/eliza/Code/tokio/tokio-executor)
   Compiling tokio-reactor v0.1.9
   Compiling tokio-threadpool v0.1.13
   Compiling tokio-current-thread v0.1.6
   Compiling tokio-timer v0.2.10
   Compiling tokio-uds v0.2.5
   Compiling tokio-udp v0.1.3
   Compiling tokio-tcp v0.1.3
   Compiling tokio-fs v0.1.6
   Compiling tokio v0.1.18 (/Users/eliza/Code/tokio/tokio)
    Finished dev [unoptimized + debuginfo] target(s) in 7.04s
     Running `target/debug/examples/chat`
server running on localhost:6142
```

Signed-off-by: Eliza Weisman <eliza@buoyant.io>

Signed-off-by: Eliza Weisman <eliza@buoyant.io>

1 files changed, 0 insertions, 257 deletions

diff --git a/examples/connect.rs b/examples/connect.rs
deleted file mode 100644
index 4dc0ea31..00000000
--- a/examples/connect.rs
+++ /dev/null
@@ -1,257 +0,0 @@
-//! An example of hooking up stdin/stdout to either a TCP or UDP stream.
-//!
-//! This example will connect to a socket address specified in the argument list
-//! and then forward all data read on stdin to the server, printing out all data
-//! received on stdout. An optional `--udp` argument can be passed to specify
-//! that the connection should be made over UDP instead of TCP, translating each
-//! line entered on stdin to a UDP packet to be sent to the remote address.
-//!
-//! Note that this is not currently optimized for performance, especially
-//! around buffer management. Rather it's intended to show an example of
-//! working with a client.
-//!
-//! This example can be quite useful when interacting with the other examples in
-//! this repository! Many of them recommend running this as a simple "hook up
-//! stdin/stdout to a server" to get up and running.
-
-#![deny(warnings)]
-
-extern crate bytes;
-extern crate futures;
-extern crate tokio;
-extern crate tokio_io;
-
-use std::env;
-use std::io::{self, Read, Write};
-use std::net::SocketAddr;
-use std::thread;
-
-use futures::sync::mpsc;
-use tokio::prelude::*;
-
-fn main() -> Result<(), Box<std::error::Error>> {
-    // Determine if we're going to run in TCP or UDP mode
-    let mut args = env::args().skip(1).collect::<Vec<_>>();
-    let tcp = match args.iter().position(|a| a == "--udp") {
-        Some(i) => {
-            args.remove(i);
-            false
-        }
-        None => true,
-    };
-
-    // Parse what address we're going to connect to
-    let addr = match args.first() {
-        Some(addr) => addr,
-        None => Err("this program requires at least one argument")?,
-    };
-    let addr = addr.parse::<SocketAddr>()?;
-
-    // Right now Tokio doesn't support a handle to stdin running on the event
-    // loop, so we farm out that work to a separate thread. This thread will
-    // read data (with blocking I/O) from stdin and then send it to the event
-    // loop over a standard futures channel.
-    let (stdin_tx, stdin_rx) = mpsc::channel(0);
-    thread::spawn(|| read_stdin(stdin_tx));
-    let stdin_rx = stdin_rx.map_err(|_| panic!("errors not possible on rx"));
-
-    // Now that we've got our stdin read we either set up our TCP connection or
-    // our UDP connection to get a stream of bytes we're going to emit to
-    // stdout.
-    let stdout = if tcp {
-        tcp::connect(&addr, Box::new(stdin_rx))?
-    } else {
-        udp::connect(&addr, Box::new(stdin_rx))?
-    };
-
-    // And now with our stream of bytes to write to stdout, we execute that in
-    // the event loop! Note that this is doing blocking I/O to emit data to
-    // stdout, and in general it's a no-no to do that sort of work on the event
-    // loop. In this case, though, we know it's ok as the event loop isn't
-    // otherwise running anything useful.
-    let mut out = io::stdout();
-
-    tokio::run({
-        stdout
-            .for_each(move |chunk| out.write_all(&chunk))
-            .map_err(|e| println!("error reading stdout; error = {:?}", e))
-    });
-    Ok(())
-}
-
-mod codec {
-    use bytes::{BufMut, BytesMut};
-    use std::io;
-    use tokio::codec::{Decoder, Encoder};
-
-    /// A simple `Codec` implementation that just ships bytes around.
-    ///
-    /// This type is used for "framing" a TCP/UDP stream of bytes but it's really
-    /// just a convenient method for us to work with streams/sinks for now.
-    /// This'll just take any data read and interpret it as a "frame" and
-    /// conversely just shove data into the output location without looking at
-    /// it.
-    pub struct Bytes;
-
-    impl Decoder for Bytes {
-        type Item = BytesMut;
-        type Error = io::Error;
-
-        fn decode(&mut self, buf: &mut BytesMut) -> io::Result<Option<BytesMut>> {
-            if buf.len() > 0 {
-                let len = buf.len();
-                Ok(Some(buf.split_to(len)))
-            } else {
-                Ok(None)
-            }
-        }
-    }
-
-    impl Encoder for Bytes {
-        type Item = Vec<u8>;
-        type Error = io::Error;
-
-        fn encode(&mut self, data: Vec<u8>, buf: &mut BytesMut) -> io::Result<()> {
-            buf.put(&data[..]);
-            Ok(())
-        }
-    }
-}
-
-mod tcp {
-    use tokio;
-    use tokio::codec::Decoder;
-    use tokio::net::TcpStream;
-    use tokio::prelude::*;
-
-    use bytes::BytesMut;
-    use codec::Bytes;
-
-    use std::error::Error;
-    use std::io;
-    use std::net::SocketAddr;
-
-    pub fn connect(
-        addr: &SocketAddr,
-        stdin: Box<Stream<Item = Vec<u8>, Error = io::Error> + Send>,
-    ) -> Result<Box<Stream<Item = BytesMut, Error = io::Error> + Send>, Box<Error>> {
-        let tcp = TcpStream::connect(addr);
-
-        // After the TCP connection has been established, we set up our client
-        // to start forwarding data.
-        //
-        // First we use the `Io::framed` method with a simple implementation of
-        // a `Codec` (listed below) that just ships bytes around. We then split
-        // that in two to work with the stream and sink separately.
-        //
-        // Half of the work we're going to do is to take all data we receive on
-        // `stdin` and send that along the TCP stream (`sink`). The second half
-        // is to take all the data we receive (`stream`) and then write that to
-        // stdout. We'll be passing this handle back out from this method.
-        //
-        // You'll also note that we *spawn* the work to read stdin and write it
-        // to the TCP stream. This is done to ensure that happens concurrently
-        // with us reading data from the stream.
-        let stream = Box::new(
-            tcp.map(move |stream| {
-                let (sink, stream) = Bytes.framed(stream).split();
-
-                tokio::spawn(stdin.forward(sink).then(|result| {
-                    if let Err(e) = result {
-                        println!("failed to write to socket: {}", e)
-                    }
-                    Ok(())
-                }));
-
-                stream
-            })
-            .flatten_stream(),
-        );
-        Ok(stream)
-    }
-}
-
-mod udp {
-    use std::error::Error;
-    use std::io;
-    use std::net::SocketAddr;
-
-    use bytes::BytesMut;
-    use tokio;
-    use tokio::net::{UdpFramed, UdpSocket};
-    use tokio::prelude::*;
-
-    use codec::Bytes;
-
-    pub fn connect(
-        &addr: &SocketAddr,
-        stdin: Box<Stream<Item = Vec<u8>, Error = io::Error> + Send>,
-    ) -> Result<Box<Stream<Item = BytesMut, Error = io::Error> + Send>, Box<Error>> {
-        // We'll bind our UDP socket to a local IP/port, but for now we
-        // basically let the OS pick both of those.
-        let addr_to_bind = if addr.ip().is_ipv4() {
-            "0.0.0.0:0".parse()?
-        } else {
-            "[::]:0".parse()?
-        };
-        let udp = match UdpSocket::bind(&addr_to_bind) {
-            Ok(udp) => udp,
-            Err(_) => Err("failed to bind socket")?,
-        };
-
-        // Like above with TCP we use an instance of `Bytes` codec to transform
-        // this UDP socket into a framed sink/stream which operates over
-        // discrete values. In this case we're working with *pairs* of socket
-        // addresses and byte buffers.
-        let (sink, stream) = UdpFramed::new(udp, Bytes).split();
-
-        // All bytes from `stdin` will go to the `addr` specified in our
-        // argument list. Like with TCP this is spawned concurrently
-        let forward_stdin = stdin
-            .map(move |chunk| (chunk, addr))
-            .forward(sink)
-            .then(|result| {
-                if let Err(e) = result {
-                    println!("failed to write to socket: {}", e)
-                }
-                Ok(())
-            });
-
-        // With UDP we could receive data from any source, so filter out
-        // anything coming from a different address
-        let receive = stream.filter_map(move |(chunk, src)| {
-            if src == addr {
-                Some(chunk.into())
-            } else {
-                None
-            }
-        });
-
-        let stream = Box::new(
-            future::lazy(|| {
-                tokio::spawn(forward_stdin);
-                future::ok(receive)
-            })
-            .flatten_stream(),
-        );
-        Ok(stream)
-    }
-}
-
-// Our helper method which will read data from stdin and send it along the
-// sender provided.
-fn read_stdin(mut tx: mpsc::Sender<Vec<u8>>) {
-    let mut stdin = io::stdin();
-    loop {
-        let mut buf = vec![0; 1024];
-        let n = match stdin.read(&mut buf) {
-            Err(_) | Ok(0) => break,
-            Ok(n) => n,
-        };
-        buf.truncate(n);
-        tx = match tx.send(buf).wait() {
-            Ok(tx) => tx,
-            Err(_) => break,
-        };
-    }
-}