From 3ad844cfe2cc130779ff876a5581b1cec02f6d3f Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <guillaume1.gomez@gmail.com>
Date: Sat, 18 Mar 2017 15:33:56 +0100
Subject: [PATCH] Add more explanation on RefCell::get_mut

---
 src/libcore/cell.rs | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/libcore/cell.rs b/src/libcore/cell.rs
index ba04cbb0543..f62057b3a52 100644
--- a/src/libcore/cell.rs
+++ b/src/libcore/cell.rs
@@ -725,6 +725,15 @@ impl<T: ?Sized> RefCell<T> {
     /// This call borrows `RefCell` mutably (at compile-time) so there is no
     /// need for dynamic checks.
     ///
+    /// However be cautious: this method expects `self` to be mutable, which is
+    /// generally not the case when using a `RefCell`. Take a look at the
+    /// [`borrow_mut`] method instead if `self` isn't mutable.
+    ///
+    /// Also, please be aware that this method is only for special circumstances and is usually
+    /// not you want. In case of doubt, use [`borrow_mut`] instead.
+    ///
+    /// [`borrow_mut`]: #method.borrow_mut
+    ///
     /// # Examples
     ///
     /// ```