tokio-xmpp: Error out when both tls-native and tls-rust features are enabled

If the user enables the tls-rust feature and forgets to disable
default-features (which includes tls-native), tell them and bail out.

The code was made to work anyway when both are enabled, and here it
defaults to tls-native. It does seem better to have one explicitely
choose one though hence the compile_error! message.

Signed-off-by: Maxime “pep” Buquet <pep@bouah.net>

tokio-xmpp/src/client/async_client.rs

@@ -7,7 +7,7 @@ use tokio::net::TcpStream;
 use tokio::task::JoinHandle;
 #[cfg(feature = "tls-native")]
 use tokio_native_tls::TlsStream;
-#[cfg(feature = "tls-rust")]
+#[cfg(all(feature = "tls-rust", not(feature = "tls-native")))]
 use tokio_rustls::client::TlsStream;
 use xmpp_parsers::{ns, Element, Jid};
 

tokio-xmpp/src/client/simple_client.rs

@@ -7,7 +7,7 @@ use std::task::{Context, Poll};
 use tokio::net::TcpStream;
 #[cfg(feature = "tls-native")]
 use tokio_native_tls::TlsStream;
-#[cfg(feature = "tls-rust")]
+#[cfg(all(feature = "tls-rust", not(feature = "tls-native")))]
 use tokio_rustls::client::TlsStream;
 use tokio_stream::StreamExt;
 use xmpp_parsers::{ns, Element, Jid};