Rollup merge of #66038 - jdxcode:char-len, r=alexcrichton

doc(str): show example of chars().count() under len()

the docs are great at explaining that .len() isn't like in other
languages but stops short of explaining how to get the character length.

1 files changed, 7 insertions, 2 deletions

diff --git a/src/liballoc/string.rs b/src/liballoc/string.rs
index d9927c642b2..0e5746d0d9d 100644
--- a/src/liballoc/string.rs
+++ b/src/liballoc/string.rs
@@ -1402,7 +1402,9 @@ impl String {
         &mut self.vec
     }
 
-    /// Returns the length of this `String`, in bytes.
+    /// Returns the length of this `String`, in bytes, not [`char`]s or
+    /// graphemes. In other words, it may not be what a human considers the
+    /// length of the string.
     ///
     /// # Examples
     ///
@@ -1410,8 +1412,11 @@ impl String {
     ///
     /// ```
     /// let a = String::from("foo");
-    ///
     /// assert_eq!(a.len(), 3);
+    ///
+    /// let fancy_f = String::from("ƒoo");
+    /// assert_eq!(fancy_f.len(), 4);
+    /// assert_eq!(fancy_f.chars().count(), 3);
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]