chore: Update to 2021 edition (#1188)

tonic/Cargo.toml

@@ -14,7 +14,7 @@ description = """
 A gRPC over HTTP/2 implementation focused on high performance, interoperability, and flexibility.
 """
 documentation = "https://docs.rs/tonic/0.8.2/tonic/"
-edition = "2018"
+edition = "2021"
 homepage = "https://github.com/hyperium/tonic"
 keywords = ["rpc", "grpc", "async", "futures", "protobuf"]
 license = "MIT"

tonic/benches-disabled/benchmarks/compiled_protos/helloworld.rs

@@ -22,7 +22,7 @@ pub mod client {
         #[doc = r" Attempt to create a new client by connecting to a given endpoint."]
         pub async fn connect<D>(dst: D) -> Result<Self, tonic::transport::Error>
         where
-            D: std::convert::TryInto<tonic::transport::Endpoint>,
+            D: TryInto<tonic::transport::Endpoint>,
             D::Error: Into<StdError>,
         {
             let conn = tonic::transport::Endpoint::new(dst)?.connect().await?;

tonic/src/metadata/value.rs

@@ -7,7 +7,6 @@ use super::key::MetadataKey;
 
 use bytes::Bytes;
 use http::header::HeaderValue;
-use std::convert::TryFrom;
 use std::error::Error;
 use std::hash::{Hash, Hasher};
 use std::marker::PhantomData;
@@ -286,7 +285,6 @@ impl<VE: ValueEncoding> MetadataValue<VE> {
 ///
 /// ```
 /// # use tonic::metadata::*;
-/// # use std::convert::TryFrom;
 /// let val = AsciiMetadataValue::try_from(b"hello\xfa").unwrap();
 /// assert_eq!(val, &b"hello\xfa"[..]);
 /// ```
@@ -295,7 +293,6 @@ impl<VE: ValueEncoding> MetadataValue<VE> {
 ///
 /// ```
 /// # use tonic::metadata::*;
-/// # use std::convert::TryFrom;
 /// let val = AsciiMetadataValue::try_from(b"\n");
 /// assert!(val.is_err());
 /// ```
@@ -324,7 +321,6 @@ impl<'a, VE: ValueEncoding> TryFrom<&'a [u8]> for MetadataValue<VE> {
 ///
 /// ```
 /// # use tonic::metadata::*;
-/// # use std::convert::TryFrom;
 /// let val = AsciiMetadataValue::try_from(b"hello\xfa").unwrap();
 /// assert_eq!(val, &b"hello\xfa"[..]);
 /// ```
@@ -333,7 +329,6 @@ impl<'a, VE: ValueEncoding> TryFrom<&'a [u8]> for MetadataValue<VE> {
 ///
 /// ```
 /// # use tonic::metadata::*;
-/// # use std::convert::TryFrom;
 /// let val = AsciiMetadataValue::try_from(b"\n");
 /// assert!(val.is_err());
 /// ```
@@ -473,7 +468,6 @@ impl MetadataValue<Ascii> {
     ///
     /// ```
     /// # use tonic::metadata::*;
-    /// # use std::convert::TryFrom;
     /// let val = AsciiMetadataValue::from_key::<Ascii>("accept".parse().unwrap());
     /// assert_eq!(val, AsciiMetadataValue::try_from(b"accept").unwrap());
     /// ```

tonic/src/transport/channel/endpoint.rs

@@ -7,14 +7,7 @@ use crate::transport::service::TlsConnector;
 use crate::transport::{service::SharedExec, Error, Executor};
 use bytes::Bytes;
 use http::{uri::Uri, HeaderValue};
-use std::{
-    convert::{TryFrom, TryInto},
-    fmt,
-    future::Future,
-    pin::Pin,
-    str::FromStr,
-    time::Duration,
-};
+use std::{fmt, future::Future, pin::Pin, str::FromStr, time::Duration};
 use tower::make::MakeConnection;
 // use crate::transport::E
 

tonic/src/transport/service/connector.rs

@@ -3,8 +3,6 @@ use super::io::BoxedIo;
 #[cfg(feature = "tls")]
 use super::tls::TlsConnector;
 use http::Uri;
-#[cfg(feature = "tls-roots-common")]
-use std::convert::TryInto;
 use std::fmt;
 use std::task::{Context, Poll};
 use tower::make::MakeConnection;

tonic/src/transport/service/tls.rs

@@ -5,8 +5,6 @@ use crate::transport::{
 };
 #[cfg(feature = "tls-roots")]
 use rustls_native_certs;
-#[cfg(feature = "tls")]
-use std::convert::TryInto;
 use std::{fmt, sync::Arc};
 use tokio::io::{AsyncRead, AsyncWrite};
 #[cfg(feature = "tls")]