Fix doctests

Author: SimonSapin

src/libcore/cell.rs

@@ -582,10 +582,11 @@ impl<'b, T: ?Sized> Ref<'b, T> {
     /// # Example
     ///
     /// ```
-    /// use std::cell::{RefCell, Ref, map_ref};
+    /// # #![feature(cell_extras)]
+    /// use std::cell::{RefCell, Ref};
     ///
     /// let c = RefCell::new((5, 'b'));
-    /// let b1: Ref<(u32, char)>> = c.borrow();
+    /// let b1: Ref<(u32, char)> = c.borrow();
     /// let b2: Ref<u32> = Ref::map(b1, |t| &t.0);
     /// assert_eq!(*b2, 5)
     /// ```
@@ -611,12 +612,13 @@ impl<'b, T: ?Sized> Ref<'b, T> {
     /// # Example
     ///
     /// ```
-    /// use std::cell::{RefCell, Ref, map_ref};
+    /// # #![feature(cell_extras)]
+    /// use std::cell::{RefCell, Ref};
     ///
     /// let c = RefCell::new(Ok(5));
     /// let b1: Ref<Result<u32, ()>> = c.borrow();
-    /// let b2: Option<Ref<u32>> = Ref::filter_map(b1, |o| o.as_ref().ok());
-    /// assert_eq!(*b2.unwrap(), 5)
+    /// let b2: Ref<u32> = Ref::filter_map(b1, |o| o.as_ref().ok()).unwrap();
+    /// assert_eq!(*b2, 5)
     /// ```
     #[unstable(feature = "cell_extras", reason = "recently added")]
     #[inline]
@@ -642,12 +644,13 @@ impl<'b, T: ?Sized> RefMut<'b, T> {
     /// # Example
     ///
     /// ```
-    /// use std::cell::{RefCell, RefMut, map_ref_mut};
+    /// # #![feature(cell_extras)]
+    /// use std::cell::{RefCell, RefMut};
     ///
     /// let c = RefCell::new((5, 'b'));
     /// {
     ///     let b1: RefMut<(u32, char)> = c.borrow_mut();
-    ///     let b2: RefMut<u32> = RefMut::map(b1, |t| &mut t.0);
+    ///     let mut b2: RefMut<u32> = RefMut::map(b1, |t| &mut t.0);
     ///     assert_eq!(*b2, 5);
     ///     *b2 = 42;
     /// }
@@ -675,14 +678,15 @@ impl<'b, T: ?Sized> RefMut<'b, T> {
     /// # Example
     ///
     /// ```
-    /// use std::cell::{RefCell, RefMut, map_ref_mut};
+    /// # #![feature(cell_extras)]
+    /// use std::cell::{RefCell, RefMut};
     ///
     /// let c = RefCell::new(Ok(5));
     /// {
     ///     let b1: RefMut<Result<u32, ()>> = c.borrow_mut();
-    ///     let b2: Option<RefMut<u32>> = RefMut::map(b1, |o| o.as_mut().ok());
-    ///     assert_eq!(*b2.unwrap(), 5);
-    ///     *b2.unwrap() = 42;
+    ///     let mut b2: RefMut<u32> = RefMut::filter_map(b1, |o| o.as_mut().ok()).unwrap();
+    ///     assert_eq!(*b2, 5);
+    ///     *b2 = 42;
     /// }
     /// assert_eq!(*c.borrow(), Ok(42));
     /// ```