From 07ccf67f59d08bcc12705121fbbed3f844b9689c Mon Sep 17 00:00:00 2001
From: Vojtech Kral <vojtech@kral.pm>
Date: Wed, 23 Nov 2022 15:36:51 +0100
Subject: [PATCH] Document split{_ascii,}_whitespace() for empty strings

---
 library/core/src/str/mod.rs | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/library/core/src/str/mod.rs b/library/core/src/str/mod.rs
index fbc0fc397a5..c0167388713 100644
--- a/library/core/src/str/mod.rs
+++ b/library/core/src/str/mod.rs
@@ -902,6 +902,12 @@ impl str {
     ///
     /// assert_eq!(None, iter.next());
     /// ```
+    ///
+    /// If the string is empty or all whitespace, the iterator yields no string slices:
+    /// ```
+    /// assert_eq!("".split_whitespace().next(), None);
+    /// assert_eq!("   ".split_whitespace().next(), None);
+    /// ```
     #[must_use = "this returns the split string as an iterator, \
                   without modifying the original"]
     #[stable(feature = "split_whitespace", since = "1.1.0")]
@@ -946,6 +952,12 @@ impl str {
     ///
     /// assert_eq!(None, iter.next());
     /// ```
+    ///
+    /// If the string is empty or all ASCII whitespace, the iterator yields no string slices:
+    /// ```
+    /// assert_eq!("".split_ascii_whitespace().next(), None);
+    /// assert_eq!("   ".split_ascii_whitespace().next(), None);
+    /// ```
     #[must_use = "this returns the split string as an iterator, \
                   without modifying the original"]
     #[stable(feature = "split_ascii_whitespace", since = "1.34.0")]