Add client, client codegen, helloworld and routeguide client examples

tonic-examples/src/helloworld/client.rs

@@ -0,0 +1,32 @@
+#![feature(async_await)]
+
+use tokio::net::TcpStream;
+use tower_h2::{add_origin::AddOrigin, Connection};
+
+pub mod hello_world {
+    include!(concat!(env!("OUT_DIR"), "/helloworld.rs"));
+    tonic::client!(service = "helloworld.Greeter", proto = "self");
+}
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let addr = "[::1]:50051".parse()?;
+    let io = TcpStream::connect(&addr).await?;
+
+    let origin = http::Uri::from_shared(format!("http://{}", addr).into()).unwrap();
+
+    let svc = Connection::handshake(io).await?;
+    let svc = AddOrigin::new(svc, origin);
+
+    let mut client = hello_world::GreeterClient::new(svc);
+
+    let request = tonic::Request::new(hello_world::HelloRequest {
+        name: "hello".into(),
+    });
+
+    let response = client.say_hello(request).await?;
+
+    println!("RESPONSE={:?}", response);
+
+    Ok(())
+}