From 081278eb7acc761f583351e846ebad21c88331ff Mon Sep 17 00:00:00 2001
From: Simon Sapin <simon.sapin@exyr.org>
Date: Thu, 24 Sep 2015 18:54:12 +0200
Subject: [PATCH] Utf8Error::valid_up_to: make documented semantics more
 precise/useful

---
 src/libcore/str/mod.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/libcore/str/mod.rs b/src/libcore/str/mod.rs
index 69ebcb1ab7e14..456e89d472126 100644
--- a/src/libcore/str/mod.rs
+++ b/src/libcore/str/mod.rs
@@ -115,8 +115,8 @@ impl Utf8Error {
     /// Returns the index in the given string up to which valid UTF-8 was
     /// verified.
     ///
-    /// Starting at the index provided, but not necessarily at it precisely, an
-    /// invalid UTF-8 encoding sequence was found.
+    /// It is the maximum index such that `from_utf8(input[..index])`
+    /// would return `Some(_)`.
     #[unstable(feature = "utf8_error", reason = "method just added",
                issue = "27734")]
     pub fn valid_up_to(&self) -> usize { self.valid_up_to }