Auto merge of #23654 - alexcrichton:rollup, r=alexcrichton

3 files changed, 13 insertions, 9 deletions

diff --git a/src/libstd/io/buffered.rs b/src/libstd/io/buffered.rs
index 43eec695274..4def601f1c0 100644
--- a/src/libstd/io/buffered.rs
+++ b/src/libstd/io/buffered.rs
@@ -258,7 +258,7 @@ impl<W> FromError<IntoInnerError<W>> for Error {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<W> error::Error for IntoInnerError<W> {
+impl<W: Send + fmt::Debug> error::Error for IntoInnerError<W> {
     fn description(&self) -> &str {
         error::Error::description(self.error())
     }
diff --git a/src/libstd/io/cursor.rs b/src/libstd/io/cursor.rs
index 87e5a2a4488..79f0af670b4 100644
--- a/src/libstd/io/cursor.rs
+++ b/src/libstd/io/cursor.rs
@@ -17,20 +17,18 @@ use iter::repeat;
 use num::Int;
 use slice;
 
-/// A `Cursor` is a type which wraps another I/O object to provide a `Seek`
+/// A `Cursor` is a type which wraps a non-I/O object to provide a `Seek`
 /// implementation.
 ///
-/// Cursors are currently typically used with memory buffer objects in order to
-/// allow `Seek` plus `Read` and `Write` implementations. For example, common
-/// cursor types include:
+/// Cursors are typically used with memory buffer objects in order to allow
+/// `Seek`, `Read`, and `Write` implementations. For example, common cursor types
+/// include `Cursor<Vec<u8>>` and `Cursor<&[u8]>`.
 ///
-/// * `Cursor<Vec<u8>>`
-/// * `Cursor<&[u8]>`
-///
-/// Implementations of the I/O traits for `Cursor<T>` are not currently generic
+/// Implementations of the I/O traits for `Cursor<T>` are currently not generic
 /// over `T` itself. Instead, specific implementations are provided for various
 /// in-memory buffer types like `Vec<u8>` and `&[u8]`.
 #[stable(feature = "rust1", since = "1.0.0")]
+#[derive(Clone, Debug)]
 pub struct Cursor<T> {
     inner: T,
     pos: u64,
diff --git a/src/libstd/io/mod.rs b/src/libstd/io/mod.rs
index 237435d6dfb..39c718c96b3 100644
--- a/src/libstd/io/mod.rs
+++ b/src/libstd/io/mod.rs
@@ -558,6 +558,12 @@ pub trait BufRead: Read {
     /// This function does not perform any I/O, it simply informs this object
     /// that some amount of its buffer, returned from `fill_buf`, has been
     /// consumed and should no longer be returned.
+    ///
+    /// This function is used to tell the buffer how many bytes you've consumed
+    /// from the return value of `fill_buf`, and so may do odd things if
+    /// `fill_buf` isn't called before calling this.
+    ///
+    /// The `amt` must be `<=` the number of bytes in the buffer returned by `fill_buf`.
     #[stable(feature = "rust1", since = "1.0.0")]
     fn consume(&mut self, amt: usize);