diff --git a/src/doc/book/functions.md b/src/doc/book/functions.md
index be905599c6441..31c9da3fadae2 100644
--- a/src/doc/book/functions.md
+++ b/src/doc/book/functions.md
@@ -68,7 +68,7 @@ You get this error:
 
 ```text
 expected one of `!`, `:`, or `@`, found `)`
-fn print_number(x, y) {
+fn print_sum(x, y) {
 ```
 
 This is a deliberate design decision. While full-program inference is possible,
diff --git a/src/doc/book/strings.md b/src/doc/book/strings.md
index 751619d544a4a..68c7235975e8c 100644
--- a/src/doc/book/strings.md
+++ b/src/doc/book/strings.md
@@ -39,7 +39,7 @@ The second, with a `\`, trims the spaces and the newline:
 
 ```rust
 let s = "foo\
-    bar"; 
+    bar";
 
 assert_eq!("foobar", s);
 ```
diff --git a/src/libcore/num/mod.rs b/src/libcore/num/mod.rs
index d094f05374b78..ed370bb91648f 100644
--- a/src/libcore/num/mod.rs
+++ b/src/libcore/num/mod.rs
@@ -479,7 +479,7 @@ macro_rules! int_impl {
             }
         }
 
-        /// Checked negation. Computes `!self`, returning `None` if `self ==
+        /// Checked negation. Computes `-self`, returning `None` if `self ==
         /// MIN`.
         ///
         /// # Examples
diff --git a/src/libcore/ptr.rs b/src/libcore/ptr.rs
index a826f2bb4440f..3cbb2f17be78b 100644
--- a/src/libcore/ptr.rs
+++ b/src/libcore/ptr.rs
@@ -127,8 +127,7 @@ pub unsafe fn read<T>(src: *const T) -> T {
     tmp
 }
 
-/// Variant of read_and_zero that writes the specific drop-flag byte
-/// (which may be more appropriate than zero).
+#[allow(missing_docs)]
 #[inline(always)]
 #[unstable(feature = "filling_drop",
            reason = "may play a larger role in std::ptr future extensions",
diff --git a/src/libcore/str/mod.rs b/src/libcore/str/mod.rs
index fa169416a1081..4d367cfd432f9 100644
--- a/src/libcore/str/mod.rs
+++ b/src/libcore/str/mod.rs
@@ -157,7 +157,7 @@ impl Utf8Error {
     /// // std::str::from_utf8 returns a Utf8Error
     /// let error = str::from_utf8(&sparkle_heart).unwrap_err();
     ///
-    /// // the first byte is invalid here
+    /// // the second byte is invalid here
     /// assert_eq!(1, error.valid_up_to());
     /// ```
     #[stable(feature = "utf8_error", since = "1.5.0")]
@@ -174,10 +174,10 @@ impl Utf8Error {
 ///
 /// If you are sure that the byte slice is valid UTF-8, and you don't want to
 /// incur the overhead of the validity check, there is an unsafe version of
-/// this function, [`from_utf8_unchecked()`][fromutf8], which has the same
+/// this function, [`from_utf8_unchecked()`][fromutf8u], which has the same
 /// behavior but skips the check.
 ///
-/// [fromutf8]: fn.from_utf8.html
+/// [fromutf8u]: fn.from_utf8_unchecked.html
 ///
 /// If you need a `String` instead of a `&str`, consider
 /// [`String::from_utf8()`][string].
@@ -275,7 +275,7 @@ unsafe fn from_raw_parts_mut<'a>(p: *mut u8, len: usize) -> &'a mut str {
 /// Converts a slice of bytes to a string slice without checking
 /// that the string contains valid UTF-8.
 ///
-/// See the safe version, [`from_utf8()`][fromutf8], for more.
+/// See the safe version, [`from_utf8()`][fromutf8], for more information.
 ///
 /// [fromutf8]: fn.from_utf8.html
 ///