1 files changed, 5 insertions, 0 deletions
diff --git a/src/libstd/sys/windows/os_str.rs b/src/libstd/sys/windows/os_str.rs
index ef260f9c5d2..4cff23b2f4a 100644
--- a/src/libstd/sys/windows/os_str.rs
+++ b/src/libstd/sys/windows/os_str.rs
@@ -80,6 +80,11 @@ impl Buf {
         unsafe { mem::transmute(self.inner.as_slice()) }
     }
 
+    #[inline]
+    pub fn as_mut_slice(&mut self) -> &mut Slice {
+        unsafe { mem::transmute(self.inner.as_mut_slice()) }
+    }
+
     pub fn into_string(self) -> Result<String, Buf> {
         self.inner.into_string().map_err(|buf| Buf { inner: buf })
     }