auto merge of #8294 : erickt/rust/map-move, r=bblum

According to #7887, we've decided to use the syntax of `fn map<U>(f: &fn(&T) -> U) -> U`, which passes a reference to the closure, and to `fn map_move<U>(f: &fn(T) -> U) -> U` which moves the value into the closure. This PR adds these `.map_move()` functions to `Option` and `Result`.

In addition, it has these other minor features:
 
* Replaces a couple uses of `option.get()`, `result.get()`, and `result.get_err()` with `option.unwrap()`, `result.unwrap()`, and `result.unwrap_err()`. (See #8268 and #8288 for a more thorough adaptation of this functionality.
* Removes `option.take_map()` and `option.take_map_default()`. These two functions can be easily written as `.take().map_move(...)`.
* Adds a better error message to `result.unwrap()` and `result.unwrap_err()`.

1 files changed, 4 insertions, 4 deletions

diff --git a/src/libstd/iterator.rs b/src/libstd/iterator.rs
index 1be398966bb..29f54bd10fb 100644
--- a/src/libstd/iterator.rs
+++ b/src/libstd/iterator.rs
@@ -674,7 +674,7 @@ impl<A, T: Iterator<A>> IteratorUtil<A> for T {
                     Some((y, y_val))
                 }
             }
-        }).map_consume(|(x, _)| x)
+        }).map_move(|(x, _)| x)
     }
 
     #[inline]
@@ -689,7 +689,7 @@ impl<A, T: Iterator<A>> IteratorUtil<A> for T {
                     Some((y, y_val))
                 }
             }
-        }).map_consume(|(x, _)| x)
+        }).map_move(|(x, _)| x)
     }
 }
 
@@ -1382,7 +1382,7 @@ impl<'self, A, T: Iterator<A>, B, U: Iterator<B>> Iterator<B> for
                     return Some(x)
                 }
             }
-            match self.iter.next().map_consume(|x| (self.f)(x)) {
+            match self.iter.next().map_move(|x| (self.f)(x)) {
                 None => return self.backiter.chain_mut_ref(|it| it.next()),
                 next => self.frontiter = next,
             }
@@ -1414,7 +1414,7 @@ impl<'self,
                     y => return y
                 }
             }
-            match self.iter.next_back().map_consume(|x| (self.f)(x)) {
+            match self.iter.next_back().map_move(|x| (self.f)(x)) {
                 None => return self.frontiter.chain_mut_ref(|it| it.next_back()),
                 next => self.backiter = next,
             }