From abb704ec78bd69c0911c5f7711646d443da4c84d Mon Sep 17 00:00:00 2001
From: Jonathan Behrens <fintelia@gmail.com>
Date: Thu, 26 Jul 2018 00:42:59 +0100
Subject: [PATCH] State default capacity for BufReader/BufWriter

---
 src/libstd/io/buffered.rs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/libstd/io/buffered.rs b/src/libstd/io/buffered.rs
index 189569683a9cf..2babf508fdcc3 100644
--- a/src/libstd/io/buffered.rs
+++ b/src/libstd/io/buffered.rs
@@ -61,7 +61,8 @@ pub struct BufReader<R> {
 }
 
 impl<R: Read> BufReader<R> {
-    /// Creates a new `BufReader` with a default buffer capacity.
+    /// Creates a new `BufReader` with a default buffer capacity. The default is currently 8 KB,
+    /// but may change in the future.
     ///
     /// # Examples
     ///
@@ -454,7 +455,8 @@ pub struct BufWriter<W: Write> {
 pub struct IntoInnerError<W>(W, Error);
 
 impl<W: Write> BufWriter<W> {
-    /// Creates a new `BufWriter` with a default buffer capacity.
+    /// Creates a new `BufWriter` with a default buffer capacity. The default is currently 8 KB,
+    /// but may change in the future.
     ///
     /// # Examples
     ///