Operator dispatch

src/doc/guide.md

@@ -4601,20 +4601,24 @@ returns `true` or `false`. The new iterator `filter()` produces
 only the elements that that closure returns `true` for:
 
 ```{rust}
-for i in range(1i, 100i).filter(|x| x % 2 == 0) {
+for i in range(1i, 100i).filter(|&x| x % 2 == 0) {
     println!("{}", i);
 }
 ```
 
 This will print all of the even numbers between one and a hundred.
+(Note that because `filter` doesn't consume the elements that are
+being iterated over, it is passed a reference to each element, and
+thus the filter predicate uses the `&x` pattern to extract the integer
+itself.)
 
 You can chain all three things together: start with an iterator, adapt it
 a few times, and then consume the result. Check it out:
 
 ```{rust}
 range(1i, 1000i)
-    .filter(|x| x % 2 == 0)
-    .filter(|x| x % 3 == 0)
+    .filter(|&x| x % 2 == 0)
+    .filter(|&x| x % 3 == 0)
     .take(5)
     .collect::<Vec<int>>();
 ```

src/libarena/lib.rs

@@ -132,7 +132,7 @@ impl Drop for Arena {
 
 #[inline]
 fn round_up(base: uint, align: uint) -> uint {
-    (base.checked_add(&(align - 1))).unwrap() & !(&(align - 1))
+    (base.checked_add(&(align - 1))).unwrap() & !(align - 1)
 }
 
 // Walk down a chunk, running the destructors for any objects stored

src/libcollections/slice.rs

@@ -1598,15 +1598,15 @@ mod tests {
     #[test]
     fn test_total_ord() {
         let c: &[int] = &[1, 2, 3];
-        [1, 2, 3, 4].cmp(& c) == Greater;
+        [1, 2, 3, 4][].cmp(& c) == Greater;
         let c: &[int] = &[1, 2, 3, 4];
-        [1, 2, 3].cmp(& c) == Less;
+        [1, 2, 3][].cmp(& c) == Less;
         let c: &[int] = &[1, 2, 3, 6];
-        [1, 2, 3, 4].cmp(& c) == Equal;
+        [1, 2, 3, 4][].cmp(& c) == Equal;
         let c: &[int] = &[1, 2, 3, 4, 5, 6];
-        [1, 2, 3, 4, 5, 5, 5, 5].cmp(& c) == Less;
+        [1, 2, 3, 4, 5, 5, 5, 5][].cmp(& c) == Less;
         let c: &[int] = &[1, 2, 3, 4];
-        [2, 2].cmp(& c) == Greater;
+        [2, 2][].cmp(& c) == Greater;
     }
 
     #[test]
@@ -1980,15 +1980,15 @@ mod tests {
             let (left, right) = values.split_at_mut(2);
             {
                 let left: &[_] = left;
-                assert!(left[0..left.len()] == [1, 2]);
+                assert!(left[0..left.len()] == [1, 2][]);
             }
             for p in left.iter_mut() {
                 *p += 1;
             }
 
             {
                 let right: &[_] = right;
-                assert!(right[0..right.len()] == [3, 4, 5]);
+                assert!(right[0..right.len()] == [3, 4, 5][]);
             }
             for p in right.iter_mut() {
                 *p += 2;

src/libcollections/vec.rs

@@ -919,7 +919,7 @@ impl<T> Vec<T> {
     ///
     /// ```
     /// let mut vec = vec![1i, 2, 3, 4];
-    /// vec.retain(|x| x%2 == 0);
+    /// vec.retain(|&x| x%2 == 0);
     /// assert_eq!(vec, vec![2, 4]);
     /// ```
     #[unstable = "the closure argument may become an unboxed closure"]
@@ -1800,15 +1800,15 @@ mod tests {
             let (left, right) = values.split_at_mut(2);
             {
                 let left: &[_] = left;
-                assert!(left[0..left.len()] == [1, 2]);
+                assert!(left[0..left.len()] == [1, 2][]);
             }
             for p in left.iter_mut() {
                 *p += 1;
             }
 
             {
                 let right: &[_] = right;
-                assert!(right[0..right.len()] == [3, 4, 5]);
+                assert!(right[0..right.len()] == [3, 4, 5][]);
             }
             for p in right.iter_mut() {
                 *p += 2;
@@ -1863,7 +1863,7 @@ mod tests {
     #[test]
     fn test_retain() {
         let mut vec = vec![1u, 2, 3, 4];
-        vec.retain(|x| x%2 == 0);
+        vec.retain(|&x| x % 2 == 0);
         assert!(vec == vec![2u, 4]);
     }
 

src/libcore/array.rs

@@ -0,0 +1,83 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+/*!
+ * Implementations of things like `Eq` for fixed-length arrays
+ * up to a certain length. Eventually we should able to generalize
+ * to all lengths.
+ */
+
+#![stable]
+#![experimental] // not yet reviewed
+
+use cmp::*;
+use option::{Option};
+
+// macro for implementing n-ary tuple functions and operations
+macro_rules! array_impls {
+    ($($N:expr)+) => {
+        $(
+            #[unstable = "waiting for PartialEq to stabilize"]
+            impl<T:PartialEq> PartialEq for [T, ..$N] {
+                #[inline]
+                fn eq(&self, other: &[T, ..$N]) -> bool {
+                    self[] == other[]
+                }
+                #[inline]
+                fn ne(&self, other: &[T, ..$N]) -> bool {
+                    self[] != other[]
+                }
+            }
+
+            #[unstable = "waiting for Eq to stabilize"]
+            impl<T:Eq> Eq for [T, ..$N] { }
+
+            #[unstable = "waiting for PartialOrd to stabilize"]
+            impl<T:PartialOrd> PartialOrd for [T, ..$N] {
+                #[inline]
+                fn partial_cmp(&self, other: &[T, ..$N]) -> Option<Ordering> {
+                    PartialOrd::partial_cmp(&self[], &other[])
+                }
+                #[inline]
+                fn lt(&self, other: &[T, ..$N]) -> bool {
+                    PartialOrd::lt(&self[], &other[])
+                }
+                #[inline]
+                fn le(&self, other: &[T, ..$N]) -> bool {
+                    PartialOrd::le(&self[], &other[])
+                }
+                #[inline]
+                fn ge(&self, other: &[T, ..$N]) -> bool {
+                    PartialOrd::ge(&self[], &other[])
+                }
+                #[inline]
+                fn gt(&self, other: &[T, ..$N]) -> bool {
+                    PartialOrd::gt(&self[], &other[])
+                }
+            }
+
+            #[unstable = "waiting for Ord to stabilize"]
+            impl<T:Ord> Ord for [T, ..$N] {
+                #[inline]
+                fn cmp(&self, other: &[T, ..$N]) -> Ordering {
+                    Ord::cmp(&self[], &other[])
+                }
+            }
+        )+
+    }
+}
+
+array_impls! {
+     0  1  2  3  4  5  6  7  8  9
+    10 11 12 13 14 15 16 17 18 19
+    20 21 22 23 24 25 26 27 28 29
+    30 31 32
+}
+

src/libcore/lib.rs

@@ -126,6 +126,10 @@ pub mod tuple;
 pub mod unit;
 pub mod fmt;
 
+// note: does not need to be public
+#[cfg(not(stage0))]
+mod array;
+
 #[doc(hidden)]
 mod core {
     pub use panicking;

src/libcore/option.rs

@@ -787,8 +787,8 @@ impl<A, V: FromIterator<A>> FromIterator<Option<A>> for Option<V> {
     /// use std::uint;
     ///
     /// let v = vec!(1u, 2u);
-    /// let res: Option<Vec<uint>> = v.iter().map(|x: &uint|
-    ///     if *x == uint::MAX { None }
+    /// let res: Option<Vec<uint>> = v.iter().map(|&x: &uint|
+    ///     if x == uint::MAX { None }
     ///     else { Some(x + 1) }
     /// ).collect();
     /// assert!(res == Some(vec!(2u, 3u)));

src/libcore/result.rs

@@ -894,8 +894,8 @@ impl<A, E, V: FromIterator<A>> FromIterator<Result<A, E>> for Result<V, E> {
     /// use std::uint;
     ///
     /// let v = vec!(1u, 2u);
-    /// let res: Result<Vec<uint>, &'static str> = v.iter().map(|x: &uint|
-    ///     if *x == uint::MAX { Err("Overflow!") }
+    /// let res: Result<Vec<uint>, &'static str> = v.iter().map(|&x: &uint|
+    ///     if x == uint::MAX { Err("Overflow!") }
     ///     else { Ok(x + 1) }
     /// ).collect();
     /// assert!(res == Ok(vec!(2u, 3u)));

src/libcoretest/iter.rs

@@ -356,7 +356,7 @@ fn test_iterator_size_hint() {
     assert_eq!(vi.zip(v2.iter()).size_hint(), (3, Some(3)));
     assert_eq!(vi.scan(0i, |_,_| Some(0i)).size_hint(), (0, Some(10)));
     assert_eq!(vi.filter(|_| false).size_hint(), (0, Some(10)));
-    assert_eq!(vi.map(|i| i+1).size_hint(), (10, Some(10)));
+    assert_eq!(vi.map(|&i| i+1).size_hint(), (10, Some(10)));
     assert_eq!(vi.filter_map(|_| Some(0i)).size_hint(), (0, Some(10)));
 }
 
@@ -388,9 +388,9 @@ fn test_any() {
 #[test]
 fn test_find() {
     let v: &[int] = &[1i, 3, 9, 27, 103, 14, 11];
-    assert_eq!(*v.iter().find(|x| *x & 1 == 0).unwrap(), 14);
-    assert_eq!(*v.iter().find(|x| *x % 3 == 0).unwrap(), 3);
-    assert!(v.iter().find(|x| *x % 12 == 0).is_none());
+    assert_eq!(*v.iter().find(|&&x| x & 1 == 0).unwrap(), 14);
+    assert_eq!(*v.iter().find(|&&x| x % 3 == 0).unwrap(), 3);
+    assert!(v.iter().find(|&&x| x % 12 == 0).is_none());
 }
 
 #[test]

src/librustc/middle/ty.rs

@@ -1167,25 +1167,25 @@ impl cmp::PartialEq for InferRegion {
 
 impl fmt::Show for TyVid {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result{
-        write!(f, "<generic #{}>", self.index)
+        write!(f, "_#{}t", self.index)
     }
 }
 
 impl fmt::Show for IntVid {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "<generic integer #{}>", self.index)
+        write!(f, "_#{}i", self.index)
     }
 }
 
 impl fmt::Show for FloatVid {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "<generic float #{}>", self.index)
+        write!(f, "_#{}f", self.index)
     }
 }
 
 impl fmt::Show for RegionVid {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "'<generic lifetime #{}>", self.index)
+        write!(f, "'_#{}r", self.index)
     }
 }
 
@@ -5566,3 +5566,18 @@ pub fn with_freevars<T>(tcx: &ty::ctxt, fid: ast::NodeId, f: |&[Freevar]| -> T)
         Some(d) => f(d.as_slice())
     }
 }
+
+impl AutoAdjustment {
+    pub fn is_identity(&self) -> bool {
+        match *self {
+            AdjustAddEnv(..) => false,
+            AdjustDerefRef(ref r) => r.is_identity(),
+        }
+    }
+}
+
+impl AutoDerefRef {
+    pub fn is_identity(&self) -> bool {
+        self.autoderefs == 0 && self.autoref.is_none()
+    }
+}