Auto merge of #18267 - lnicola:sync-from-rust, r=lnicola

minor: Sync from downstream

1 files changed, 5 insertions, 0 deletions

diff --git a/library/std/src/sync/mpmc/error.rs b/library/std/src/sync/mpmc/error.rs
index e3aec7e7623..e34b56d0831 100644
--- a/library/std/src/sync/mpmc/error.rs
+++ b/library/std/src/sync/mpmc/error.rs
@@ -7,6 +7,7 @@ use crate::{error, fmt};
 ///
 /// [`send_timeout`]: super::Sender::send_timeout
 #[derive(PartialEq, Eq, Clone, Copy)]
+#[unstable(feature = "mpmc_channel", issue = "126840")]
 pub enum SendTimeoutError<T> {
     /// The message could not be sent because the channel is full and the operation timed out.
     ///
@@ -18,12 +19,14 @@ pub enum SendTimeoutError<T> {
     Disconnected(T),
 }
 
+#[unstable(feature = "mpmc_channel", issue = "126840")]
 impl<T> fmt::Debug for SendTimeoutError<T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         "SendTimeoutError(..)".fmt(f)
     }
 }
 
+#[unstable(feature = "mpmc_channel", issue = "126840")]
 impl<T> fmt::Display for SendTimeoutError<T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match *self {
@@ -33,8 +36,10 @@ impl<T> fmt::Display for SendTimeoutError<T> {
     }
 }
 
+#[unstable(feature = "mpmc_channel", issue = "126840")]
 impl<T> error::Error for SendTimeoutError<T> {}
 
+#[unstable(feature = "mpmc_channel", issue = "126840")]
 impl<T> From<SendError<T>> for SendTimeoutError<T> {
     fn from(err: SendError<T>) -> SendTimeoutError<T> {
         match err {