diff --git a/src/liballoc/str.rs b/src/liballoc/str.rs
index 14d5e96d2e73a..d5ef41df0d850 100644
--- a/src/liballoc/str.rs
+++ b/src/liballoc/str.rs
@@ -2122,6 +2122,48 @@ impl str {
         unsafe { String::from_utf8_unchecked(buf) }
     }
 
+    /// Returns true if this `str` is entirely whitespace, and false otherwise.
+    ///
+    /// 'Whitespace' is defined according to the terms of the Unicode Derived Core
+    /// Property `White_Space`.
+    ///
+    /// # Examples
+    ///
+    /// Basic usage:
+    ///
+    /// ```
+    /// assert!("    \t ".is_whitespace());
+    ///
+    /// // a non-breaking space
+    /// assert!("\u{A0}".is_whitespace());
+    ///
+    /// assert!(!"   越".is_whitespace());
+    /// ```
+    #[stable(feature = "unicode_methods_on_intrinsics", since = "1.27.0")]
+    #[inline]
+    pub fn is_whitespace(&self) -> bool {
+        UnicodeStr::is_whitespace(self)
+    }
+
+    /// Returns true if this `str` is entirely alphanumeric, and false otherwise.
+    ///
+    /// 'Alphanumeric'-ness is defined in terms of the Unicode General Categories
+    /// 'Nd', 'Nl', 'No' and the Derived Core Property 'Alphabetic'.
+    ///
+    /// # Examples
+    ///
+    /// Basic usage:
+    ///
+    /// ```
+    /// assert!("٣7৬Kو藏".is_alphanumeric());
+    /// assert!(!"¾①".is_alphanumeric());
+    /// ```
+    #[stable(feature = "unicode_methods_on_intrinsics", since = "1.27.0")]
+    #[inline]
+    pub fn is_alphanumeric(&self) -> bool {
+        UnicodeStr::is_alphanumeric(self)
+    }
+
     /// Checks if all characters in this string are within the ASCII range.
     ///
     /// # Examples
diff --git a/src/librustdoc/test.rs b/src/librustdoc/test.rs
index 3ce8bd4ebb4c1..8ab9ca451871b 100644
--- a/src/librustdoc/test.rs
+++ b/src/librustdoc/test.rs
@@ -406,8 +406,6 @@ pub fn make_test(s: &str,
 
 // FIXME(aburka): use a real parser to deal with multiline attributes
 fn partition_source(s: &str) -> (String, String) {
-    use std_unicode::str::UnicodeStr;
-
     let mut after_header = false;
     let mut before = String::new();
     let mut after = String::new();