Rollup merge of #39393 - ollie27:stab_impls, r=alexcrichton

Fix a few impl stability attributes

The versions show up in rustdoc.

19 files changed, 53 insertions, 51 deletions

diff --git a/src/libstd/ascii.rs b/src/libstd/ascii.rs
index b220504d2b4..35c388ba076 100644
--- a/src/libstd/ascii.rs
+++ b/src/libstd/ascii.rs
@@ -399,7 +399,7 @@ impl ExactSizeIterator for EscapeDefault {}
 #[unstable(feature = "fused", issue = "35602")]
 impl FusedIterator for EscapeDefault {}
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for EscapeDefault {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("EscapeDefault { .. }")
diff --git a/src/libstd/collections/hash/map.rs b/src/libstd/collections/hash/map.rs
index 8058972e750..ffb7a1a1fc1 100644
--- a/src/libstd/collections/hash/map.rs
+++ b/src/libstd/collections/hash/map.rs
@@ -1283,7 +1283,7 @@ impl<'a, K, V> Clone for Iter<'a, K, V> {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<'a, K: Debug, V: Debug> fmt::Debug for Iter<'a, K, V> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_list()
@@ -1318,7 +1318,7 @@ impl<'a, K, V> Clone for Keys<'a, K, V> {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<'a, K: Debug, V: Debug> fmt::Debug for Keys<'a, K, V> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_list()
@@ -1341,7 +1341,7 @@ impl<'a, K, V> Clone for Values<'a, K, V> {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<'a, K: Debug, V: Debug> fmt::Debug for Values<'a, K, V> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_list()
@@ -1591,7 +1591,7 @@ impl<'a, K, V> ExactSizeIterator for IterMut<'a, K, V> {
 #[unstable(feature = "fused", issue = "35602")]
 impl<'a, K, V> FusedIterator for IterMut<'a, K, V> {}
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<'a, K, V> fmt::Debug for IterMut<'a, K, V>
     where K: fmt::Debug,
           V: fmt::Debug,
@@ -1626,7 +1626,7 @@ impl<K, V> ExactSizeIterator for IntoIter<K, V> {
 #[unstable(feature = "fused", issue = "35602")]
 impl<K, V> FusedIterator for IntoIter<K, V> {}
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<K: Debug, V: Debug> fmt::Debug for IntoIter<K, V> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_list()
@@ -1704,7 +1704,7 @@ impl<'a, K, V> ExactSizeIterator for ValuesMut<'a, K, V> {
 #[unstable(feature = "fused", issue = "35602")]
 impl<'a, K, V> FusedIterator for ValuesMut<'a, K, V> {}
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<'a, K, V> fmt::Debug for ValuesMut<'a, K, V>
     where K: fmt::Debug,
           V: fmt::Debug,
@@ -1739,7 +1739,7 @@ impl<'a, K, V> ExactSizeIterator for Drain<'a, K, V> {
 #[unstable(feature = "fused", issue = "35602")]
 impl<'a, K, V> FusedIterator for Drain<'a, K, V> {}
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<'a, K, V> fmt::Debug for Drain<'a, K, V>
     where K: fmt::Debug,
           V: fmt::Debug,
@@ -2227,7 +2227,7 @@ impl Default for RandomState {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for RandomState {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("RandomState { .. }")
diff --git a/src/libstd/collections/hash/set.rs b/src/libstd/collections/hash/set.rs
index 341b050862f..a3f7e13bbf9 100644
--- a/src/libstd/collections/hash/set.rs
+++ b/src/libstd/collections/hash/set.rs
@@ -948,7 +948,7 @@ impl<'a, K> ExactSizeIterator for Iter<'a, K> {
 #[unstable(feature = "fused", issue = "35602")]
 impl<'a, K> FusedIterator for Iter<'a, K> {}
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<'a, K: fmt::Debug> fmt::Debug for Iter<'a, K> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_list()
@@ -977,7 +977,7 @@ impl<K> ExactSizeIterator for IntoIter<K> {
 #[unstable(feature = "fused", issue = "35602")]
 impl<K> FusedIterator for IntoIter<K> {}
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<K: fmt::Debug> fmt::Debug for IntoIter<K> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         let entries_iter = self.iter.inner.iter().map(|(k, _)| k);
@@ -1007,7 +1007,7 @@ impl<'a, K> ExactSizeIterator for Drain<'a, K> {
 #[unstable(feature = "fused", issue = "35602")]
 impl<'a, K> FusedIterator for Drain<'a, K> {}
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<'a, K: fmt::Debug> fmt::Debug for Drain<'a, K> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         let entries_iter = self.iter.inner.iter().map(|(k, _)| k);
@@ -1050,7 +1050,7 @@ impl<'a, T, S> Iterator for Intersection<'a, T, S>
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<'a, T, S> fmt::Debug for Intersection<'a, T, S>
     where T: fmt::Debug + Eq + Hash,
           S: BuildHasher,
@@ -1109,7 +1109,7 @@ impl<'a, T, S> FusedIterator for Difference<'a, T, S>
 {
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<'a, T, S> fmt::Debug for Difference<'a, T, S>
     where T: fmt::Debug + Eq + Hash,
           S: BuildHasher,
@@ -1150,7 +1150,7 @@ impl<'a, T, S> FusedIterator for SymmetricDifference<'a, T, S>
 {
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<'a, T, S> fmt::Debug for SymmetricDifference<'a, T, S>
     where T: fmt::Debug + Eq + Hash,
           S: BuildHasher,
@@ -1176,7 +1176,7 @@ impl<'a, T, S> FusedIterator for Union<'a, T, S>
 {
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<'a, T, S> fmt::Debug for Union<'a, T, S>
     where T: fmt::Debug + Eq + Hash,
           S: BuildHasher,
diff --git a/src/libstd/env.rs b/src/libstd/env.rs
index c3a6b2433ed..29f2ac6ab44 100644
--- a/src/libstd/env.rs
+++ b/src/libstd/env.rs
@@ -145,7 +145,7 @@ impl Iterator for Vars {
     fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for Vars {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("Vars { .. }")
@@ -159,7 +159,7 @@ impl Iterator for VarsOs {
     fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for VarsOs {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("VarsOs { .. }")
@@ -382,7 +382,7 @@ impl<'a> Iterator for SplitPaths<'a> {
     fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<'a> fmt::Debug for SplitPaths<'a> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("SplitPaths { .. }")
@@ -665,7 +665,7 @@ impl DoubleEndedIterator for Args {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for Args {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("Args { .. }")
@@ -690,7 +690,7 @@ impl DoubleEndedIterator for ArgsOs {
     fn next_back(&mut self) -> Option<OsString> { self.inner.next_back() }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for ArgsOs {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("ArgsOs { .. }")
diff --git a/src/libstd/fs.rs b/src/libstd/fs.rs
index 249627c430c..e5562d05f10 100644
--- a/src/libstd/fs.rs
+++ b/src/libstd/fs.rs
@@ -869,7 +869,7 @@ impl Metadata {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for Metadata {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_struct("Metadata")
diff --git a/src/libstd/io/mod.rs b/src/libstd/io/mod.rs
index de5fc5bfad1..8cb7b2bda75 100644
--- a/src/libstd/io/mod.rs
+++ b/src/libstd/io/mod.rs
@@ -1450,7 +1450,7 @@ pub struct Chain<T, U> {
     done_first: bool,
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<T: fmt::Debug, U: fmt::Debug> fmt::Debug for Chain<T, U> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_struct("Chain")
diff --git a/src/libstd/io/stdio.rs b/src/libstd/io/stdio.rs
index 83a675eb512..e16e8019b5f 100644
--- a/src/libstd/io/stdio.rs
+++ b/src/libstd/io/stdio.rs
@@ -282,7 +282,7 @@ impl Stdin {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for Stdin {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("Stdin { .. }")
@@ -321,7 +321,7 @@ impl<'a> BufRead for StdinLock<'a> {
     fn consume(&mut self, n: usize) { self.inner.consume(n) }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<'a> fmt::Debug for StdinLock<'a> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("StdinLock { .. }")
@@ -438,7 +438,7 @@ impl Stdout {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for Stdout {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("Stdout { .. }")
@@ -470,7 +470,7 @@ impl<'a> Write for StdoutLock<'a> {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<'a> fmt::Debug for StdoutLock<'a> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("StdoutLock { .. }")
@@ -573,7 +573,7 @@ impl Stderr {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for Stderr {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("Stderr { .. }")
@@ -605,7 +605,7 @@ impl<'a> Write for StderrLock<'a> {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<'a> fmt::Debug for StderrLock<'a> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("StderrLock { .. }")
diff --git a/src/libstd/io/util.rs b/src/libstd/io/util.rs
index e50665120eb..4163187488e 100644
--- a/src/libstd/io/util.rs
+++ b/src/libstd/io/util.rs
@@ -98,7 +98,7 @@ impl BufRead for Empty {
     fn consume(&mut self, _n: usize) {}
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for Empty {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("Empty { .. }")
@@ -141,7 +141,7 @@ impl Read for Repeat {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for Repeat {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("Repeat { .. }")
@@ -180,7 +180,7 @@ impl Write for Sink {
     fn flush(&mut self) -> io::Result<()> { Ok(()) }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for Sink {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("Sink { .. }")
diff --git a/src/libstd/net/mod.rs b/src/libstd/net/mod.rs
index 2b60fc38198..b0d2e3e4687 100644
--- a/src/libstd/net/mod.rs
+++ b/src/libstd/net/mod.rs
@@ -106,7 +106,10 @@ impl Iterator for LookupHost {
     fn next(&mut self) -> Option<SocketAddr> { self.0.next() }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[unstable(feature = "lookup_host", reason = "unsure about the returned \
+                                              iterator and returning socket \
+                                              addresses",
+           issue = "27705")]
 impl fmt::Debug for LookupHost {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("LookupHost { .. }")
diff --git a/src/libstd/os/raw.rs b/src/libstd/os/raw.rs
index cc154f7ab41..68d4ca90019 100644
--- a/src/libstd/os/raw.rs
+++ b/src/libstd/os/raw.rs
@@ -73,7 +73,7 @@ pub enum c_void {
     #[doc(hidden)] __variant2,
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for c_void {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("c_void")
diff --git a/src/libstd/panic.rs b/src/libstd/panic.rs
index faf4949e861..ac0d0d2afb8 100644
--- a/src/libstd/panic.rs
+++ b/src/libstd/panic.rs
@@ -297,7 +297,7 @@ impl<R, F: FnOnce() -> R> FnOnce<()> for AssertUnwindSafe<F> {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<T: fmt::Debug> fmt::Debug for AssertUnwindSafe<T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_tuple("AssertUnwindSafe")
diff --git a/src/libstd/process.rs b/src/libstd/process.rs
index 23a53d777a5..c16b97ebda5 100644
--- a/src/libstd/process.rs
+++ b/src/libstd/process.rs
@@ -114,7 +114,7 @@ impl IntoInner<imp::Process> for Child {
     fn into_inner(self) -> imp::Process { self.handle }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for Child {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_struct("Child")
@@ -160,7 +160,7 @@ impl FromInner<AnonPipe> for ChildStdin {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for ChildStdin {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("ChildStdin { .. }")
@@ -201,7 +201,7 @@ impl FromInner<AnonPipe> for ChildStdout {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for ChildStdout {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("ChildStdout { .. }")
@@ -242,7 +242,7 @@ impl FromInner<AnonPipe> for ChildStderr {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for ChildStderr {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("ChildStderr { .. }")
@@ -696,7 +696,7 @@ impl FromInner<imp::Stdio> for Stdio {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for Stdio {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("Stdio { .. }")
diff --git a/src/libstd/sync/barrier.rs b/src/libstd/sync/barrier.rs
index b8e83dced8d..fc4fd4ce92b 100644
--- a/src/libstd/sync/barrier.rs
+++ b/src/libstd/sync/barrier.rs
@@ -55,7 +55,7 @@ struct BarrierState {
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct BarrierWaitResult(bool);
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for Barrier {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("Barrier { .. }")
@@ -110,7 +110,7 @@ impl Barrier {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for BarrierWaitResult {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_struct("BarrierWaitResult")
diff --git a/src/libstd/sync/condvar.rs b/src/libstd/sync/condvar.rs
index 5c85c4879a8..7ee1c98565c 100644
--- a/src/libstd/sync/condvar.rs
+++ b/src/libstd/sync/condvar.rs
@@ -240,7 +240,7 @@ impl Condvar {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for Condvar {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("Condvar { .. }")
diff --git a/src/libstd/sync/mutex.rs b/src/libstd/sync/mutex.rs
index 2efddeb4610..0d6ad5e38e9 100644
--- a/src/libstd/sync/mutex.rs
+++ b/src/libstd/sync/mutex.rs
@@ -428,7 +428,7 @@ impl<'a, T: ?Sized> Drop for MutexGuard<'a, T> {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<'a, T: ?Sized + fmt::Debug> fmt::Debug for MutexGuard<'a, T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_struct("MutexGuard")
diff --git a/src/libstd/sync/once.rs b/src/libstd/sync/once.rs
index a9747639aac..ba993751391 100644
--- a/src/libstd/sync/once.rs
+++ b/src/libstd/sync/once.rs
@@ -330,7 +330,7 @@ impl Once {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for Once {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("Once { .. }")
diff --git a/src/libstd/sync/rwlock.rs b/src/libstd/sync/rwlock.rs
index adbb98e4b1f..a3db0adeda0 100644
--- a/src/libstd/sync/rwlock.rs
+++ b/src/libstd/sync/rwlock.rs
@@ -361,7 +361,7 @@ impl<'rwlock, T: ?Sized> RwLockWriteGuard<'rwlock, T> {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<'a, T: fmt::Debug> fmt::Debug for RwLockReadGuard<'a, T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_struct("RwLockReadGuard")
@@ -370,7 +370,7 @@ impl<'a, T: fmt::Debug> fmt::Debug for RwLockReadGuard<'a, T> {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<'a, T: fmt::Debug> fmt::Debug for RwLockWriteGuard<'a, T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_struct("RwLockWriteGuard")
diff --git a/src/libstd/thread/local.rs b/src/libstd/thread/local.rs
index 01584979aab..5166ddf8a21 100644
--- a/src/libstd/thread/local.rs
+++ b/src/libstd/thread/local.rs
@@ -99,7 +99,7 @@ pub struct LocalKey<T: 'static> {
     init: fn() -> T,
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<T: 'static> fmt::Debug for LocalKey<T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("LocalKey { .. }")
@@ -332,7 +332,6 @@ pub mod os {
         marker: marker::PhantomData<Cell<T>>,
     }
 
-    #[stable(feature = "std_debug", since = "1.15.0")]
     impl<T> fmt::Debug for Key<T> {
         fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
             f.pad("Key { .. }")
diff --git a/src/libstd/thread/mod.rs b/src/libstd/thread/mod.rs
index 8789006436c..93e320c4522 100644
--- a/src/libstd/thread/mod.rs
+++ b/src/libstd/thread/mod.rs
@@ -698,7 +698,7 @@ impl ThreadId {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[unstable(feature = "thread_id", issue = "21507")]
 impl fmt::Debug for ThreadId {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("ThreadId { .. }")
@@ -1002,7 +1002,7 @@ impl<T> IntoInner<imp::Thread> for JoinHandle<T> {
     fn into_inner(self) -> imp::Thread { self.0.native.unwrap() }
 }
 
-#[stable(feature = "std_debug", since = "1.15.0")]
+#[stable(feature = "std_debug", since = "1.16.0")]
 impl<T> fmt::Debug for JoinHandle<T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.pad("JoinHandle { .. }")