Provide ipv6 example

examples/ipv6.rs

@@ -0,0 +1,40 @@
+use std::io;
+use std::net::{SocketAddr, ToSocketAddrs};
+use ureq::Resolver;
+pub struct Ipv6Resolver;
+
+impl Resolver for Ipv6Resolver {
+    fn resolve(&self, netloc: &str) -> io::Result<Vec<SocketAddr>> {
+        ToSocketAddrs::to_socket_addrs(netloc).map(|iter| {
+            let vec = iter
+                // only keep ipv6 addresses
+                .filter(|s| s.is_ipv6())
+                .collect::<Vec<SocketAddr>>();
+
+            if vec.is_empty() {
+                println!(
+                    "Failed to find any ipv6 addresses. This probably means \
+                    the DNS server didn't return any."
+                );
+            }
+
+            vec
+        })
+    }
+}
+
+pub fn main() {
+    let agent = ureq::builder().resolver(Ipv6Resolver).build();
+
+    let result = agent.get("https://www.google.com/").call();
+
+    match result {
+        Err(err) => {
+            println!("{:?}", err);
+            std::process::exit(1);
+        }
+        Ok(response) => {
+            assert_eq!(response.status(), 200);
+        }
+    }
+}