---

yaml
---
r: 233719
b: refs/heads/beta
c: fc7c0f9
h: refs/heads/master
i:
  233717: 4e1e5e4
  233715: f6b1a4b
  233711: a2be484
v: v3

Author: birkenfeld

[refs]

@@ -23,7 +23,7 @@ refs/tags/0.9: 36870b185fc5f5486636d4515f0e22677493f225
 refs/tags/0.10: ac33f2b15782272ae348dbd7b14b8257b2148b5a
 refs/tags/0.11.0: e1247cb1d0d681be034adb4b558b5a0c0d5720f9
 refs/tags/0.12.0: f0c419429ef30723ceaf6b42f9b5a2aeb5d2e2d1
-refs/heads/beta: ef3255b063a28ef1ed8346192325cfac66398739
+refs/heads/beta: fc7c0f99d7cb5616230f7a61e86bcb4fc01dab5e
 refs/tags/1.0.0-alpha: e42bd6d93a1d3433c486200587f8f9e12590a4d7
 refs/heads/tmp: 370fe2786109360f7c35b8ba552b83b773dd71d6
 refs/tags/1.0.0-alpha.2: 4c705f6bc559886632d3871b04f58aab093bfa2f

branches/beta/src/doc/reference.md

@@ -1881,15 +1881,11 @@ type int8_t = i8;
 - `no_start` - disable linking to the `native` crate, which specifies the
   "start" language item.
 - `no_std` - disable linking to the `std` crate.
-- `plugin` - load a list of named crates as compiler plugins, e.g.
+- `plugin` — load a list of named crates as compiler plugins, e.g.
              `#![plugin(foo, bar)]`. Optional arguments for each plugin,
              i.e. `#![plugin(foo(... args ...))]`, are provided to the plugin's
              registrar function.  The `plugin` feature gate is required to use
              this attribute.
-- `recursion_limit` - Sets the maximum depth for potentially
-                      infinitely-recursive compile-time operations like
-                      auto-dereference or macro expansion. The default is
-                      `#![recursion_limit="64"]`.
 
 ### Module-only attributes
 

branches/beta/src/libcore/iter.rs

@@ -184,7 +184,7 @@ pub trait Iterator {
     fn chain<U>(self, other: U) -> Chain<Self, U::IntoIter> where
         Self: Sized, U: IntoIterator<Item=Self::Item>,
     {
-        Chain{a: self, b: other.into_iter(), state: ChainState::Both}
+        Chain{a: self, b: other.into_iter(), flag: false}
     }
 
     /// Creates an iterator that iterates over both this and the specified
@@ -1277,30 +1277,7 @@ impl<I> Iterator for Cycle<I> where I: Clone + Iterator {
 pub struct Chain<A, B> {
     a: A,
     b: B,
-    state: ChainState,
-}
-
-// The iterator protocol specifies that iteration ends with the return value
-// `None` from `.next()` (or `.next_back()`) and it is unspecified what
-// further calls return. The chain adaptor must account for this since it uses
-// two subiterators.
-//
-//  It uses three states:
-//
-//  - Both: `a` and `b` are remaining
-//  - Front: `a` remaining
-//  - Back: `b` remaining
-//
-//  The fourth state (neither iterator is remaining) only occurs after Chain has
-//  returned None once, so we don't need to store this state.
-#[derive(Clone)]
-enum ChainState {
-    // both front and back iterator are remaining
-    Both,
-    // only front is remaining
-    Front,
-    // only back is remaining
-    Back,
+    flag: bool,
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1312,58 +1289,42 @@ impl<A, B> Iterator for Chain<A, B> where
 
     #[inline]
     fn next(&mut self) -> Option<A::Item> {
-        match self.state {
-            ChainState::Both => match self.a.next() {
-                elt @ Some(..) => return elt,
-                None => {
-                    self.state = ChainState::Back;
-                    self.b.next()
-                }
-            },
-            ChainState::Front => self.a.next(),
-            ChainState::Back => self.b.next(),
+        if self.flag {
+            self.b.next()
+        } else {
+            match self.a.next() {
+                Some(x) => return Some(x),
+                _ => ()
+            }
+            self.flag = true;
+            self.b.next()
         }
     }
 
     #[inline]
     fn count(self) -> usize {
-        match self.state {
-            ChainState::Both => self.a.count() + self.b.count(),
-            ChainState::Front => self.a.count(),
-            ChainState::Back => self.b.count(),
-        }
+        (if !self.flag { self.a.count() } else { 0 }) + self.b.count()
     }
 
     #[inline]
     fn nth(&mut self, mut n: usize) -> Option<A::Item> {
-        match self.state {
-            ChainState::Both | ChainState::Front => {
-                for x in self.a.by_ref() {
-                    if n == 0 {
-                        return Some(x)
-                    }
-                    n -= 1;
-                }
-                if let ChainState::Both = self.state {
-                    self.state = ChainState::Back;
+        if !self.flag {
+            for x in self.a.by_ref() {
+                if n == 0 {
+                    return Some(x)
                 }
+                n -= 1;
             }
-            ChainState::Back => {}
-        }
-        if let ChainState::Back = self.state {
-            self.b.nth(n)
-        } else {
-            None
+            self.flag = true;
         }
+        self.b.nth(n)
     }
 
     #[inline]
     fn last(self) -> Option<A::Item> {
-        match self.state {
-            ChainState::Both => self.b.last().or(self.a.last()),
-            ChainState::Front => self.a.last(),
-            ChainState::Back => self.b.last()
-        }
+        let a_last = if self.flag { None } else { self.a.last() };
+        let b_last = self.b.last();
+        b_last.or(a_last)
     }
 
     #[inline]
@@ -1389,16 +1350,9 @@ impl<A, B> DoubleEndedIterator for Chain<A, B> where
 {
     #[inline]
     fn next_back(&mut self) -> Option<A::Item> {
-        match self.state {
-            ChainState::Both => match self.b.next_back() {
-                elt @ Some(..) => return elt,
-                None => {
-                    self.state = ChainState::Front;
-                    self.a.next_back()
-                }
-            },
-            ChainState::Front => self.a.next_back(),
-            ChainState::Back => self.b.next_back(),
+        match self.b.next_back() {
+            Some(x) => Some(x),
+            None => self.a.next_back()
         }
     }
 }

branches/beta/src/libcoretest/iter.rs

@@ -729,26 +729,6 @@ fn test_double_ended_chain() {
     assert_eq!(it.next_back().unwrap(), &5);
     assert_eq!(it.next_back().unwrap(), &7);
     assert_eq!(it.next_back(), None);
-
-
-    // test that .chain() is well behaved with an unfused iterator
-    struct CrazyIterator(bool);
-    impl CrazyIterator { fn new() -> CrazyIterator { CrazyIterator(false) } }
-    impl Iterator for CrazyIterator {
-        type Item = i32;
-        fn next(&mut self) -> Option<i32> {
-            if self.0 { Some(99) } else { self.0 = true; None }
-        }
-    }
-
-    impl DoubleEndedIterator for CrazyIterator {
-        fn next_back(&mut self) -> Option<i32> {
-            self.next()
-        }
-    }
-
-    assert_eq!(CrazyIterator::new().chain(0..10).rev().last(), Some(0));
-    assert!((0..10).chain(CrazyIterator::new()).rev().any(|i| i == 0));
 }
 
 #[test]

branches/beta/src/libstd/collections/mod.rs

@@ -25,9 +25,9 @@
 //!
 //! Rust's collections can be grouped into four major categories:
 //!
-//! * Sequences: `Vec`, `VecDeque`, `LinkedList`, `BitVec`
-//! * Maps: `HashMap`, `BTreeMap`, `VecMap`
-//! * Sets: `HashSet`, `BTreeSet`, `BitSet`
+//! * Sequences: `Vec`, `VecDeque`, `LinkedList`
+//! * Maps: `HashMap`, `BTreeMap`
+//! * Sets: `HashSet`, `BTreeSet`
 //! * Misc: `BinaryHeap`
 //!
 //! # When Should You Use Which Collection?
@@ -70,22 +70,11 @@
 //! * You want to be able to get all of the entries in order on-demand.
 //! * You want a sorted map.
 //!
-//! ### Use a `VecMap` when:
-//! * You want a `HashMap` but with known to be small `usize` keys.
-//! * You want a `BTreeMap`, but with known to be small `usize` keys.
-//!
 //! ### Use the `Set` variant of any of these `Map`s when:
 //! * You just want to remember which keys you've seen.
 //! * There is no meaningful value to associate with your keys.
 //! * You just want a set.
 //!
-//! ### Use a `BitVec` when:
-//! * You want to store an unbounded number of booleans in a small space.
-//! * You want a bit vector.
-//!
-//! ### Use a `BitSet` when:
-//! * You want a `BitVec`, but want `Set` properties
-//!
 //! ### Use a `BinaryHeap` when:
 //!
 //! * You want to store a bunch of elements, but only ever want to process the
@@ -123,31 +112,20 @@
 //! | Vec          | O(1)           | O(n-i)*         | O(n-i)         | O(m)*  | O(n-i)         |
 //! | VecDeque     | O(1)           | O(min(i, n-i))* | O(min(i, n-i)) | O(m)*  | O(min(i, n-i)) |
 //! | LinkedList   | O(min(i, n-i)) | O(min(i, n-i))  | O(min(i, n-i)) | O(1)   | O(min(i, n-i)) |
-//! | BitVec       | O(1)           | O(n-i)*         | O(n-i)         | O(m)*  | O(n-i)         |
 //!
 //! Note that where ties occur, Vec is generally going to be faster than VecDeque, and VecDeque
-//! is generally going to be faster than LinkedList. BitVec is not a general purpose collection, and
-//! therefore cannot reasonably be compared.
+//! is generally going to be faster than LinkedList.
 //!
 //! ## Maps
 //!
-//! For Sets, all operations have the cost of the equivalent Map operation. For
-//! BitSet,
-//! refer to VecMap.
+//! For Sets, all operations have the cost of the equivalent Map operation.
 //!
 //! |          | get       | insert   | remove   | predecessor |
 //! |----------|-----------|----------|----------|-------------|
 //! | HashMap  | O(1)~     | O(1)~*   | O(1)~    | N/A         |
 //! | BTreeMap | O(log n)  | O(log n) | O(log n) | O(log n)    |
-//! | VecMap   | O(1)      | O(1)?    | O(1)     | O(n)        |
-//!
-//! Note that VecMap is *incredibly* inefficient in terms of space. The O(1)
-//! insertion time assumes space for the element is already allocated.
-//! Otherwise, a large key may require a massive reallocation, with no direct
-//! relation to the number of elements in the collection.  VecMap should only be
-//! seriously considered for small keys.
 //!
-//! Note also that BTreeMap's precise performance depends on the value of B.
+//! Note that BTreeMap's precise performance depends on the value of B.
 //!
 //! # Correct and Efficient Usage of Collections
 //!

branches/beta/src/libstd/sys/windows/os.rs

@@ -74,15 +74,16 @@ pub fn error_string(errnum: i32) -> String {
                                  langId,
                                  buf.as_mut_ptr(),
                                  buf.len() as DWORD,
-                                 ptr::null()) as usize;
+                                 ptr::null());
         if res == 0 {
             // Sometimes FormatMessageW can fail e.g. system doesn't like langId,
             let fm_err = errno();
             return format!("OS Error {} (FormatMessageW() returned error {})",
                            errnum, fm_err);
         }
 
-        match String::from_utf16(&buf[..res]) {
+        let b = buf.iter().position(|&b| b == 0).unwrap_or(buf.len());
+        match String::from_utf16(&buf[..b]) {
             Ok(mut msg) => {
                 // Trim trailing CRLF inserted by FormatMessageW
                 let len = msg.trim_right().len();