diff --git a/src/libstd/ascii.rs b/src/libstd/ascii.rs
index 031a9b8bec274..a8a3353da4c00 100644
--- a/src/libstd/ascii.rs
+++ b/src/libstd/ascii.rs
@@ -160,108 +160,6 @@ pub trait AsciiExt {
     /// ```
     #[unstable(feature = "ascii", issue = "27809")]
     fn make_ascii_lowercase(&mut self);
-
-    /// Converts this type to its ASCII upper case,
-    /// consuming the value to avoid allocating memory where `to_ascii_uppercase` would.
-    ///
-    /// See `to_ascii_uppercase` for more information.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use std::ascii::AsciiExt;
-    ///
-    /// let ascii: String = "a".to_owned();
-    ///
-    /// let upper = ascii.into_ascii_uppercase();
-    ///
-    /// assert_eq!(upper, "A");
-    /// ```
-    #[stable(feature = "into_ascii", since = "1.8.0")]
-    fn into_ascii_uppercase(self) -> Self::Owned where Self: Sized {
-        self.to_ascii_uppercase()
-    }
-
-    /// Converts this type to its ASCII lower case,
-    /// consuming the value to avoid allocating memory where `to_ascii_lowercase` would.
-    ///
-    /// See `to_ascii_lowercase` for more information.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use std::ascii::AsciiExt;
-    ///
-    /// let ascii: String = "A".to_owned();
-    ///
-    /// let lower = ascii.into_ascii_lowercase();
-    ///
-    /// assert_eq!(lower, "a");
-    /// ```
-    #[stable(feature = "into_ascii", since = "1.8.0")]
-    fn into_ascii_lowercase(self) -> Self::Owned where Self: Sized {
-        self.to_ascii_lowercase()
-    }
-}
-
-/// Implement `into_ascii_lowercase` and `into_ascii_uppercase` without memory allocation,
-/// defer other methods to `str`.
-#[stable(feature = "into_ascii", since = "1.8.0")]
-impl AsciiExt for String {
-    type Owned = Self;
-
-    #[inline] fn is_ascii(&self) -> bool { (**self).is_ascii() }
-    #[inline] fn to_ascii_uppercase(&self) -> Self { (**self).to_ascii_uppercase() }
-    #[inline] fn to_ascii_lowercase(&self) -> Self { (**self).to_ascii_lowercase() }
-    #[inline] fn eq_ignore_ascii_case(&self, o: &Self) -> bool { (**self).eq_ignore_ascii_case(o) }
-    #[inline] fn make_ascii_uppercase(&mut self) { (**self).make_ascii_uppercase() }
-    #[inline] fn make_ascii_lowercase(&mut self) { (**self).make_ascii_lowercase() }
-
-    fn into_ascii_lowercase(mut self) -> Self {
-        unsafe {
-            for byte in self.as_mut_vec() {
-                *byte = byte.to_ascii_lowercase()
-            }
-        }
-        self
-    }
-
-    fn into_ascii_uppercase(mut self) -> Self {
-        unsafe {
-            for byte in self.as_mut_vec() {
-                *byte = byte.to_ascii_uppercase()
-            }
-        }
-        self
-    }
-}
-
-/// Implement `into_ascii_lowercase` and `into_ascii_uppercase` without memory allocation,
-/// defer other methods to `[u8]`.
-#[stable(feature = "into_ascii", since = "1.8.0")]
-impl AsciiExt for Vec<u8> {
-    type Owned = Self;
-
-    #[inline] fn is_ascii(&self) -> bool { (**self).is_ascii() }
-    #[inline] fn to_ascii_uppercase(&self) -> Self { (**self).to_ascii_uppercase() }
-    #[inline] fn to_ascii_lowercase(&self) -> Self { (**self).to_ascii_lowercase() }
-    #[inline] fn eq_ignore_ascii_case(&self, o: &Self) -> bool { (**self).eq_ignore_ascii_case(o) }
-    #[inline] fn make_ascii_uppercase(&mut self) { (**self).make_ascii_uppercase() }
-    #[inline] fn make_ascii_lowercase(&mut self) { (**self).make_ascii_lowercase() }
-
-    fn into_ascii_lowercase(mut self) -> Self {
-        for byte in &mut self {
-            *byte = byte.to_ascii_lowercase()
-        }
-        self
-    }
-
-    fn into_ascii_uppercase(mut self) -> Self {
-        for byte in &mut self {
-            *byte = byte.to_ascii_uppercase()
-        }
-        self
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]