1 files changed, 7 insertions, 30 deletions
diff --git a/src/libcore/str/mod.rs b/src/libcore/str/mod.rs
index 013ca182c13..681dfda4ad5 100644
--- a/src/libcore/str/mod.rs
+++ b/src/libcore/str/mod.rs
@@ -9,7 +9,7 @@
 #![stable(feature = "rust1", since = "1.0.0")]
 
 use self::pattern::Pattern;
-use self::pattern::{DoubleEndedSearcher, ReverseSearcher, SearchStep, Searcher};
+use self::pattern::{DoubleEndedSearcher, ReverseSearcher, Searcher};
 
 use crate::char;
 use crate::fmt::{self, Write};
@@ -3986,26 +3986,15 @@ impl str {
     /// ```
     /// #![feature(str_strip)]
     ///
-    /// assert_eq!("foobar".strip_prefix("foo"), Some("bar"));
-    /// assert_eq!("foobar".strip_prefix("bar"), None);
+    /// assert_eq!("foo:bar".strip_prefix("foo:"), Some("bar"));
+    /// assert_eq!("foo:bar".strip_prefix("bar"), None);
     /// assert_eq!("foofoo".strip_prefix("foo"), Some("foo"));
     /// ```
     #[must_use = "this returns the remaining substring as a new slice, \
                   without modifying the original"]
     #[unstable(feature = "str_strip", reason = "newly added", issue = "67302")]
     pub fn strip_prefix<'a, P: Pattern<'a>>(&'a self, prefix: P) -> Option<&'a str> {
-        let mut matcher = prefix.into_searcher(self);
-        if let SearchStep::Match(start, len) = matcher.next() {
-            debug_assert_eq!(
-                start, 0,
-                "The first search step from Searcher \
-                 must include the first character"
-            );
-            // SAFETY: `Searcher` is known to return valid indices.
-            unsafe { Some(self.get_unchecked(len..)) }
-        } else {
-            None
-        }
+        prefix.strip_prefix_of(self)
     }
 
     /// Returns a string slice with the suffix removed.
@@ -4020,8 +4009,8 @@ impl str {
     ///
     /// ```
     /// #![feature(str_strip)]
-    /// assert_eq!("barfoo".strip_suffix("foo"), Some("bar"));
-    /// assert_eq!("barfoo".strip_suffix("bar"), None);
+    /// assert_eq!("bar:foo".strip_suffix(":foo"), Some("bar"));
+    /// assert_eq!("bar:foo".strip_suffix("bar"), None);
     /// assert_eq!("foofoo".strip_suffix("foo"), Some("foo"));
     /// ```
     #[must_use = "this returns the remaining substring as a new slice, \
@@ -4032,19 +4021,7 @@ impl str {
         P: Pattern<'a>,
         <P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
     {
-        let mut matcher = suffix.into_searcher(self);
-        if let SearchStep::Match(start, end) = matcher.next_back() {
-            debug_assert_eq!(
-                end,
-                self.len(),
-                "The first search step from ReverseSearcher \
-                 must include the last character"
-            );
-            // SAFETY: `Searcher` is known to return valid indices.
-            unsafe { Some(self.get_unchecked(..start)) }
-        } else {
-            None
-        }
+        suffix.strip_suffix_of(self)
     }
 
     /// Returns a string slice with all suffixes that match a pattern