Auto merge of #31643 - Manishearth:rollup, r=Manishearth

- Successful merges: #31535, #31537, #31542, #31559, #31563, #31582, #31584, #31585, #31589, #31607, #31609, #31610, #31612, #31629, #31635, #31637, #31638
- Failed merges:

4 files changed, 20 insertions, 14 deletions

diff --git a/src/libstd/ascii.rs b/src/libstd/ascii.rs
index 38f79079b29..8cabdc41a05 100644
--- a/src/libstd/ascii.rs
+++ b/src/libstd/ascii.rs
@@ -45,7 +45,7 @@ pub trait AsciiExt {
     #[stable(feature = "rust1", since = "1.0.0")]
     type Owned;
 
-    /// Checks if within the ASCII range.
+    /// Checks if the value is within the ASCII range.
     ///
     /// # Examples
     ///
@@ -55,8 +55,8 @@ pub trait AsciiExt {
     /// let ascii = 'a';
     /// let utf8 = '❤';
     ///
-    /// assert_eq!(true, ascii.is_ascii());
-    /// assert_eq!(false, utf8.is_ascii())
+    /// assert!(ascii.is_ascii());
+    /// assert!(!utf8.is_ascii());
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     fn is_ascii(&self) -> bool;
@@ -114,9 +114,9 @@ pub trait AsciiExt {
     /// let ascii3 = 'A';
     /// let ascii4 = 'z';
     ///
-    /// assert_eq!(true, ascii1.eq_ignore_ascii_case(&ascii2));
-    /// assert_eq!(true, ascii1.eq_ignore_ascii_case(&ascii3));
-    /// assert_eq!(false, ascii1.eq_ignore_ascii_case(&ascii4));
+    /// assert!(ascii1.eq_ignore_ascii_case(&ascii2));
+    /// assert!(ascii1.eq_ignore_ascii_case(&ascii3));
+    /// assert!(!ascii1.eq_ignore_ascii_case(&ascii4));
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     fn eq_ignore_ascii_case(&self, other: &Self) -> bool;
diff --git a/src/libstd/macros.rs b/src/libstd/macros.rs
index b7afd12d8e5..d241cd032ed 100644
--- a/src/libstd/macros.rs
+++ b/src/libstd/macros.rs
@@ -269,9 +269,10 @@ pub mod builtin {
     /// This macro takes any number of comma-separated identifiers, and
     /// concatenates them all into one, yielding an expression which is a new
     /// identifier. Note that hygiene makes it such that this macro cannot
-    /// capture local variables, and macros are only allowed in item,
-    /// statement or expression position, meaning this macro may be difficult to
-    /// use in some situations.
+    /// capture local variables. Also, as a general rule, macros are only
+    /// allowed in item, statement or expression position. That means while
+    /// you may use this macro for referring to existing variables, functions or
+    /// modules etc, you cannot define a new one with it.
     ///
     /// # Examples
     ///
@@ -283,6 +284,8 @@ pub mod builtin {
     ///
     /// let f = concat_idents!(foo, bar);
     /// println!("{}", f());
+    ///
+    /// // fn concat_idents!(new, fun, name) { } // not usable in this way!
     /// # }
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
diff --git a/src/libstd/prelude/mod.rs b/src/libstd/prelude/mod.rs
index a0db471dece..ebd299efa78 100644
--- a/src/libstd/prelude/mod.rs
+++ b/src/libstd/prelude/mod.rs
@@ -55,7 +55,7 @@
 //! * [`std::marker`]::{[`Copy`], [`Send`], [`Sized`], [`Sync`]}. The marker
 //!   traits indicate fundamental properties of types.
 //! * [`std::ops`]::{[`Drop`], [`Fn`], [`FnMut`], [`FnOnce`]}. Various
-//!   operations for both destuctors and overloading `()`.
+//!   operations for both destructors and overloading `()`.
 //! * [`std::mem`]::[`drop`], a convenience function for explicitly dropping a
 //!   value.
 //! * [`std::boxed`]::[`Box`], a way to allocate values on the heap.
diff --git a/src/libstd/sys/common/poison.rs b/src/libstd/sys/common/poison.rs
index 2cfa04c843b..d858c002755 100644
--- a/src/libstd/sys/common/poison.rs
+++ b/src/libstd/sys/common/poison.rs
@@ -111,7 +111,7 @@ impl<T> fmt::Display for PoisonError<T> {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T: Send + Reflect> Error for PoisonError<T> {
+impl<T: Reflect> Error for PoisonError<T> {
     fn description(&self) -> &str {
         "poisoned lock: another task failed inside"
     }
@@ -158,14 +158,17 @@ impl<T> fmt::Debug for TryLockError<T> {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T: Send + Reflect> fmt::Display for TryLockError<T> {
+impl<T> fmt::Display for TryLockError<T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        self.description().fmt(f)
+        match *self {
+            TryLockError::Poisoned(..) => "poisoned lock: another task failed inside",
+            TryLockError::WouldBlock => "try_lock failed because the operation would block"
+        }.fmt(f)
     }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T: Send + Reflect> Error for TryLockError<T> {
+impl<T: Reflect> Error for TryLockError<T> {
     fn description(&self) -> &str {
         match *self {
             TryLockError::Poisoned(ref p) => p.description(),