Rollup merge of #55783 - stjepang:deprecate-select, r=SimonSapin

Deprecate mpsc channel selection

Rationale: https://github.com/rust-lang/rust/issues/27800#issuecomment-421760863

r? @SimonSapin

3 files changed, 6 insertions, 4 deletions

diff --git a/src/libstd/macros.rs b/src/libstd/macros.rs
index 34bbbb53d5f..96c92ceb5bb 100644
--- a/src/libstd/macros.rs
+++ b/src/libstd/macros.rs
@@ -399,6 +399,8 @@ macro_rules! await {
 /// For more information about select, see the `std::sync::mpsc::Select` structure.
 #[macro_export]
 #[unstable(feature = "mpsc_select", issue = "27800")]
+#[rustc_deprecated(since = "1.32.0",
+                   reason = "channel selection will be removed in a future release")]
 macro_rules! select {
     (
         $($name:pat = $rx:ident.$meth:ident() => $code:expr),+
diff --git a/src/libstd/sync/mpsc/mod.rs b/src/libstd/sync/mpsc/mod.rs
index 81f98a55c11..059ced4f56e 100644
--- a/src/libstd/sync/mpsc/mod.rs
+++ b/src/libstd/sync/mpsc/mod.rs
@@ -124,6 +124,7 @@
 //! ```
 
 #![stable(feature = "rust1", since = "1.0.0")]
+#![allow(deprecated)] // for mpsc_select
 
 // A description of how Rust's channel implementation works
 //
diff --git a/src/libstd/sync/mpsc/select.rs b/src/libstd/sync/mpsc/select.rs
index a7a284cfb79..2ec4b52dbf3 100644
--- a/src/libstd/sync/mpsc/select.rs
+++ b/src/libstd/sync/mpsc/select.rs
@@ -51,11 +51,10 @@
 #![unstable(feature = "mpsc_select",
             reason = "This implementation, while likely sufficient, is unsafe and \
                       likely to be error prone. At some point in the future this \
-                      module will likely be replaced, and it is currently \
-                      unknown how much API breakage that will cause. The ability \
-                      to select over a number of channels will remain forever, \
-                      but no guarantees beyond this are being made",
+                      module will be removed.",
             issue = "27800")]
+#![rustc_deprecated(since = "1.32.0",
+                    reason = "channel selection will be removed in a future release")]
 
 
 use fmt;