Auto merge of #28900 - cristicbz:typos, r=alexcrichton

I found these automatically, but fixed them manually to ensure the semantics are correct. I know things like these are hardly important, since they only marginally improve clarity. But at least for me typos and simple grammatical errors trigger an---unjustified---sense of unprofessionalism, despite the fact that I make them all the time and I understand that they're the sort of thing that is bound to slip through review.  

Anyway, to find most of these I used:

  * `ag '.*//.*(\b[A-Za-z]{2,}\b) \1\b'` for repeated words

  * `ag '\b(the|this|those|these|a|it) (a|the|this|those|these|it)\b'` to find constructs like 'the this' etc. many false positives, but not too hard to scroll through them to actually find the mistakes.

  * `cat ../../typos.txt | paste -d'|' - - - - - - - - - - - - - - - - - - - - - - | tr '\n' '\0' | xargs -0 -P4 -n1 ag`. Hacky way to find misspellings, but it works ok. I got `typos.txt` from [Wikipedia](https://en.wikipedia.org/wiki/Wikipedia:Lists_of_common_misspellings/For_machines)

* `ag '.*//.* a ([ae][a-z]|(o[^n])|(i[a-rt-z]))'` to find places where 'a' was followed by a vowel (requiring 'an' instead).

I also used a handful more one off regexes that are too boring to reproduce here.

3 files changed, 6 insertions, 6 deletions

diff --git a/src/libstd/io/buffered.rs b/src/libstd/io/buffered.rs
index 90bcbe7fe86..acab63315e4 100644
--- a/src/libstd/io/buffered.rs
+++ b/src/libstd/io/buffered.rs
@@ -546,7 +546,7 @@ impl<W> IntoInnerError<W> {
     /// let stream = match stream.into_inner() {
     ///     Ok(s) => s,
     ///     Err(e) => {
-    ///         // Here, e is a IntoInnerError, let's re-examine the buffer:
+    ///         // Here, e is an IntoInnerError, let's re-examine the buffer:
     ///         let buffer = e.into_inner();
     ///
     ///         // do stuff to try to recover
diff --git a/src/libstd/io/mod.rs b/src/libstd/io/mod.rs
index a76755dadd3..166909f20b7 100644
--- a/src/libstd/io/mod.rs
+++ b/src/libstd/io/mod.rs
@@ -23,7 +23,7 @@
 //! Because they are traits, they're implemented by a number of other types,
 //! and you can implement them for your types too. As such, you'll see a
 //! few different types of I/O throughout the documentation in this module:
-//! `File`s, `TcpStream`s, and somtimes even `Vec<T>`s. For example, `Read`
+//! `File`s, `TcpStream`s, and sometimes even `Vec<T>`s. For example, `Read`
 //! adds a `read()` method, which we can use on `File`s:
 //!
 //! ```
@@ -234,7 +234,7 @@
 //! The return type of `read_input()`, `io::Result<()>`, is a very common type
 //! for functions which don't have a 'real' return value, but do want to return
 //! errors if they happen. In this case, the only purpose of this function is
-//! to read the line and print it, so we use use `()`.
+//! to read the line and print it, so we use `()`.
 //!
 //! [result]: type.Result.html
 //! [try]: macro.try!.html
diff --git a/src/libstd/io/stdio.rs b/src/libstd/io/stdio.rs
index c2110ef1d83..31b881bebf0 100644
--- a/src/libstd/io/stdio.rs
+++ b/src/libstd/io/stdio.rs
@@ -146,7 +146,7 @@ pub struct Stdin {
     inner: Arc<Mutex<BufReader<Maybe<StdinRaw>>>>,
 }
 
-/// A locked reference to the a `Stdin` handle.
+/// A locked reference to the `Stdin` handle.
 ///
 /// This handle implements both the `Read` and `BufRead` traits and is
 /// constructed via the `lock` method on `Stdin`.
@@ -323,7 +323,7 @@ pub struct Stdout {
     inner: Arc<ReentrantMutex<RefCell<LineWriter<Maybe<StdoutRaw>>>>>,
 }
 
-/// A locked reference to the a `Stdout` handle.
+/// A locked reference to the `Stdout` handle.
 ///
 /// This handle implements the `Write` trait and is constructed via the `lock`
 /// method on `Stdout`.
@@ -430,7 +430,7 @@ pub struct Stderr {
     inner: Arc<ReentrantMutex<RefCell<Maybe<StderrRaw>>>>,
 }
 
-/// A locked reference to the a `Stderr` handle.
+/// A locked reference to the `Stderr` handle.
 ///
 /// This handle implements the `Write` trait and is constructed via the `lock`
 /// method on `Stderr`.