Auto merge of #23473 - Manishearth:rollup, r=Manishearth

22 files changed, 362 insertions, 117 deletions

diff --git a/src/compiletest/runtest.rs b/src/compiletest/runtest.rs
index 475c0410135..a754bd950f7 100644
--- a/src/compiletest/runtest.rs
+++ b/src/compiletest/runtest.rs
@@ -1052,22 +1052,22 @@ fn scan_char(haystack: &str, needle: char, idx: &mut uint) -> bool {
     if *idx >= haystack.len() {
         return false;
     }
-    let range = haystack.char_range_at(*idx);
-    if range.ch != needle {
+    let ch = haystack.char_at(*idx);
+    if ch != needle {
         return false;
     }
-    *idx = range.next;
+    *idx += ch.len_utf8();
     return true;
 }
 
 fn scan_integer(haystack: &str, idx: &mut uint) -> bool {
     let mut i = *idx;
     while i < haystack.len() {
-        let range = haystack.char_range_at(i);
-        if range.ch < '0' || '9' < range.ch {
+        let ch = haystack.char_at(i);
+        if ch < '0' || '9' < ch {
             break;
         }
-        i = range.next;
+        i += ch.len_utf8();
     }
     if i == *idx {
         return false;
@@ -1083,9 +1083,9 @@ fn scan_string(haystack: &str, needle: &str, idx: &mut uint) -> bool {
         if haystack_i >= haystack.len() {
             return false;
         }
-        let range = haystack.char_range_at(haystack_i);
-        haystack_i = range.next;
-        if !scan_char(needle, range.ch, &mut needle_i) {
+        let ch = haystack.char_at(haystack_i);
+        haystack_i += ch.len_utf8();
+        if !scan_char(needle, ch, &mut needle_i) {
             return false;
         }
     }
diff --git a/src/libcollections/lib.rs b/src/libcollections/lib.rs
index b75f346c188..c4a01496763 100644
--- a/src/libcollections/lib.rs
+++ b/src/libcollections/lib.rs
@@ -35,6 +35,7 @@
 #![feature(unique)]
 #![feature(unsafe_no_drop_flag)]
 #![feature(step_by)]
+#![feature(str_char)]
 #![cfg_attr(test, feature(rand, rustc_private, test))]
 #![cfg_attr(test, allow(deprecated))] // rand
 
diff --git a/src/libcollections/str.rs b/src/libcollections/str.rs
index b2273646b95..078d18a310a 100644
--- a/src/libcollections/str.rs
+++ b/src/libcollections/str.rs
@@ -175,7 +175,9 @@ enum DecompositionType {
 ///
 /// For use with the `std::iter` module.
 #[derive(Clone)]
-#[unstable(feature = "collections")]
+#[unstable(feature = "unicode",
+           reason = "this functionality may be replaced with a more generic \
+                     unicode crate on crates.io")]
 pub struct Decompositions<'a> {
     kind: DecompositionType,
     iter: Chars<'a>,
@@ -266,7 +268,9 @@ enum RecompositionState {
 ///
 /// For use with the `std::iter` module.
 #[derive(Clone)]
-#[unstable(feature = "collections")]
+#[unstable(feature = "unicode",
+           reason = "this functionality may be replaced with a more generic \
+                     unicode crate on crates.io")]
 pub struct Recompositions<'a> {
     iter: Decompositions<'a>,
     state: RecompositionState,
@@ -472,8 +476,9 @@ pub trait StrExt: Index<RangeFull, Output = str> {
     /// Returns an iterator over the string in Unicode Normalization Form D
     /// (canonical decomposition).
     #[inline]
-    #[unstable(feature = "collections",
-               reason = "this functionality may be moved to libunicode")]
+    #[unstable(feature = "unicode",
+               reason = "this functionality may be replaced with a more generic \
+                         unicode crate on crates.io")]
     fn nfd_chars(&self) -> Decompositions {
         Decompositions {
             iter: self[..].chars(),
@@ -486,8 +491,9 @@ pub trait StrExt: Index<RangeFull, Output = str> {
     /// Returns an iterator over the string in Unicode Normalization Form KD
     /// (compatibility decomposition).
     #[inline]
-    #[unstable(feature = "collections",
-               reason = "this functionality may be moved to libunicode")]
+    #[unstable(feature = "unicode",
+               reason = "this functionality may be replaced with a more generic \
+                         unicode crate on crates.io")]
     fn nfkd_chars(&self) -> Decompositions {
         Decompositions {
             iter: self[..].chars(),
@@ -500,8 +506,9 @@ pub trait StrExt: Index<RangeFull, Output = str> {
     /// An Iterator over the string in Unicode Normalization Form C
     /// (canonical decomposition followed by canonical composition).
     #[inline]
-    #[unstable(feature = "collections",
-               reason = "this functionality may be moved to libunicode")]
+    #[unstable(feature = "unicode",
+               reason = "this functionality may be replaced with a more generic \
+                         unicode crate on crates.io")]
     fn nfc_chars(&self) -> Recompositions {
         Recompositions {
             iter: self.nfd_chars(),
@@ -515,8 +522,9 @@ pub trait StrExt: Index<RangeFull, Output = str> {
     /// An Iterator over the string in Unicode Normalization Form KC
     /// (compatibility decomposition followed by canonical composition).
     #[inline]
-    #[unstable(feature = "collections",
-               reason = "this functionality may be moved to libunicode")]
+    #[unstable(feature = "unicode",
+               reason = "this functionality may be replaced with a more generic \
+                         unicode crate on crates.io")]
     fn nfkc_chars(&self) -> Recompositions {
         Recompositions {
             iter: self.nfkd_chars(),
@@ -923,11 +931,11 @@ pub trait StrExt: Index<RangeFull, Output = str> {
 
     /// Returns a string with all pre- and suffixes that match a pattern repeatedly removed.
     ///
-    /// The pattern can be a simple `&str`, or a closure that determines the split.
+    /// The pattern can be any `DoubleEndedSearcher`, including a closure that determines the split.
     ///
     /// # Examples
     ///
-    /// Simple `&str` patterns:
+    /// Simple `char` patterns:
     ///
     /// ```
     /// assert_eq!("11foo1bar11".trim_matches('1'), "foo1bar");
@@ -1023,8 +1031,11 @@ pub trait StrExt: Index<RangeFull, Output = str> {
     /// // third byte of `老`
     /// assert!(!s.is_char_boundary(8));
     /// ```
-    #[unstable(feature = "collections",
-               reason = "naming is uncertain with container conventions")]
+    #[unstable(feature = "str_char",
+               reason = "it is unclear whether this method pulls its weight \
+                         with the existence of the char_indices iterator or \
+                         this method may want to be replaced with checked \
+                         slicing")]
     fn is_char_boundary(&self, index: usize) -> bool {
         core_str::StrExt::is_char_boundary(&self[..], index)
     }
@@ -1069,8 +1080,10 @@ pub trait StrExt: Index<RangeFull, Output = str> {
     /// 14: a
     /// 15: m
     /// ```
-    #[unstable(feature = "collections",
-               reason = "naming is uncertain with container conventions")]
+    #[unstable(feature = "str_char",
+               reason = "often replaced by char_indices, this method may \
+                         be removed in favor of just char_at() or eventually \
+                         removed altogether")]
     fn char_range_at(&self, start: usize) -> CharRange {
         core_str::StrExt::char_range_at(&self[..], start)
     }
@@ -1117,8 +1130,10 @@ pub trait StrExt: Index<RangeFull, Output = str> {
     /// 6: 华
     /// 3: 中
     /// ```
-    #[unstable(feature = "collections",
-               reason = "naming is uncertain with container conventions")]
+    #[unstable(feature = "str_char",
+               reason = "often replaced by char_indices, this method may \
+                         be removed in favor of just char_at() or eventually \
+                         removed altogether")]
     fn char_range_at_reverse(&self, start: usize) -> CharRange {
         core_str::StrExt::char_range_at_reverse(&self[..], start)
     }
@@ -1137,8 +1152,12 @@ pub trait StrExt: Index<RangeFull, Output = str> {
     /// assert_eq!(s.char_at(1), 'b');
     /// assert_eq!(s.char_at(2), 'π');
     /// ```
-    #[unstable(feature = "collections",
-               reason = "naming is uncertain with container conventions")]
+    #[unstable(feature = "str_char",
+               reason = "frequently replaced by the chars() iterator, this \
+                         method may be removed or possibly renamed in the \
+                         future; it is normally replaced by chars/char_indices \
+                         iterators or by getting the first char from a \
+                         subslice")]
     fn char_at(&self, i: usize) -> char {
         core_str::StrExt::char_at(&self[..], i)
     }
@@ -1157,8 +1176,10 @@ pub trait StrExt: Index<RangeFull, Output = str> {
     /// assert_eq!(s.char_at_reverse(1), 'a');
     /// assert_eq!(s.char_at_reverse(2), 'b');
     /// ```
-    #[unstable(feature = "collections",
-               reason = "naming is uncertain with container conventions")]
+    #[unstable(feature = "str_char",
+               reason = "see char_at for more details, but reverse semantics \
+                         are also somewhat unclear, especially with which \
+                         cases generate panics")]
     fn char_at_reverse(&self, i: usize) -> char {
         core_str::StrExt::char_at_reverse(&self[..], i)
     }
@@ -1297,8 +1318,10 @@ pub trait StrExt: Index<RangeFull, Output = str> {
     /// assert_eq!(c, 'ö');
     /// assert_eq!(s2, "we 老虎 Léopard");
     /// ```
-    #[unstable(feature = "collections",
-               reason = "awaiting conventions about shifting and slices")]
+    #[unstable(feature = "str_char",
+               reason = "awaiting conventions about shifting and slices and \
+                         may not be warranted with the existence of the chars \
+                         and/or char_indices iterators")]
     fn slice_shift_char(&self) -> Option<(char, &str)> {
         core_str::StrExt::slice_shift_char(&self[..])
     }
@@ -1421,8 +1444,9 @@ pub trait StrExt: Index<RangeFull, Output = str> {
     ///
     /// assert_eq!(gr2.as_slice(), b);
     /// ```
-    #[unstable(feature = "collections",
-               reason = "this functionality may only be provided by libunicode")]
+    #[unstable(feature = "unicode",
+               reason = "this functionality may be replaced with a more generic \
+                         unicode crate on crates.io")]
     fn graphemes(&self, is_extended: bool) -> Graphemes {
         UnicodeStr::graphemes(&self[..], is_extended)
     }
@@ -1438,8 +1462,9 @@ pub trait StrExt: Index<RangeFull, Output = str> {
     ///
     /// assert_eq!(gr_inds.as_slice(), b);
     /// ```
-    #[unstable(feature = "collections",
-               reason = "this functionality may only be provided by libunicode")]
+    #[unstable(feature = "unicode",
+               reason = "this functionality may be replaced with a more generic \
+                         unicode crate on crates.io")]
     fn grapheme_indices(&self, is_extended: bool) -> GraphemeIndices {
         UnicodeStr::grapheme_indices(&self[..], is_extended)
     }
@@ -1467,13 +1492,15 @@ pub trait StrExt: Index<RangeFull, Output = str> {
     ///
     /// Control characters have zero width.
     ///
-    /// `is_cjk` determines behavior for characters in the Ambiguous category: if `is_cjk` is
-    /// `true`, these are 2 columns wide; otherwise, they are 1. In CJK locales, `is_cjk` should be
-    /// `true`, else it should be `false`.
-    /// [Unicode Standard Annex #11](http://www.unicode.org/reports/tr11/) recommends that these
-    /// characters be treated as 1 column (i.e., `is_cjk = false`) if the locale is unknown.
-    #[unstable(feature = "collections",
-               reason = "this functionality may only be provided by libunicode")]
+    /// `is_cjk` determines behavior for characters in the Ambiguous category:
+    /// if `is_cjk` is `true`, these are 2 columns wide; otherwise, they are 1.
+    /// In CJK locales, `is_cjk` should be `true`, else it should be `false`.
+    /// [Unicode Standard Annex #11](http://www.unicode.org/reports/tr11/)
+    /// recommends that these characters be treated as 1 column (i.e., `is_cjk =
+    /// false`) if the locale is unknown.
+    #[unstable(feature = "unicode",
+               reason = "this functionality may be replaced with a more generic \
+                         unicode crate on crates.io")]
     fn width(&self, is_cjk: bool) -> usize {
         UnicodeStr::width(&self[..], is_cjk)
     }
@@ -1615,8 +1642,9 @@ impl str {
     /// Returns an iterator over the string in Unicode Normalization Form D
     /// (canonical decomposition).
     #[inline]
-    #[unstable(feature = "collections",
-               reason = "this functionality may be moved to libunicode")]
+    #[unstable(feature = "unicode",
+               reason = "this functionality may be replaced with a more generic \
+                         unicode crate on crates.io")]
     pub fn nfd_chars(&self) -> Decompositions {
         Decompositions {
             iter: self[..].chars(),
@@ -1629,8 +1657,9 @@ impl str {
     /// Returns an iterator over the string in Unicode Normalization Form KD
     /// (compatibility decomposition).
     #[inline]
-    #[unstable(feature = "collections",
-               reason = "this functionality may be moved to libunicode")]
+    #[unstable(feature = "unicode",
+               reason = "this functionality may be replaced with a more generic \
+                         unicode crate on crates.io")]
     pub fn nfkd_chars(&self) -> Decompositions {
         Decompositions {
             iter: self[..].chars(),
@@ -1643,8 +1672,9 @@ impl str {
     /// An Iterator over the string in Unicode Normalization Form C
     /// (canonical decomposition followed by canonical composition).
     #[inline]
-    #[unstable(feature = "collections",
-               reason = "this functionality may be moved to libunicode")]
+    #[unstable(feature = "unicode",
+               reason = "this functionality may be replaced with a more generic \
+                         unicode crate on crates.io")]
     pub fn nfc_chars(&self) -> Recompositions {
         Recompositions {
             iter: self.nfd_chars(),
@@ -1658,8 +1688,9 @@ impl str {
     /// An Iterator over the string in Unicode Normalization Form KC
     /// (compatibility decomposition followed by canonical composition).
     #[inline]
-    #[unstable(feature = "collections",
-               reason = "this functionality may be moved to libunicode")]
+    #[unstable(feature = "unicode",
+               reason = "this functionality may be replaced with a more generic \
+                         unicode crate on crates.io")]
     pub fn nfkc_chars(&self) -> Recompositions {
         Recompositions {
             iter: self.nfkd_chars(),
@@ -2172,8 +2203,11 @@ impl str {
     /// // third byte of `老`
     /// assert!(!s.is_char_boundary(8));
     /// ```
-    #[unstable(feature = "collections",
-               reason = "naming is uncertain with container conventions")]
+    #[unstable(feature = "str_char",
+               reason = "it is unclear whether this method pulls its weight \
+                         with the existence of the char_indices iterator or \
+                         this method may want to be replaced with checked \
+                         slicing")]
     pub fn is_char_boundary(&self, index: usize) -> bool {
         core_str::StrExt::is_char_boundary(&self[..], index)
     }
@@ -2218,8 +2252,10 @@ impl str {
     /// 14: a
     /// 15: m
     /// ```
-    #[unstable(feature = "collections",
-               reason = "naming is uncertain with container conventions")]
+    #[unstable(feature = "str_char",
+               reason = "often replaced by char_indices, this method may \
+                         be removed in favor of just char_at() or eventually \
+                         removed altogether")]
     pub fn char_range_at(&self, start: usize) -> CharRange {
         core_str::StrExt::char_range_at(&self[..], start)
     }
@@ -2266,8 +2302,10 @@ impl str {
     /// 6: 华
     /// 3: 中
     /// ```
-    #[unstable(feature = "collections",
-               reason = "naming is uncertain with container conventions")]
+    #[unstable(feature = "str_char",
+               reason = "often replaced by char_indices, this method may \
+                         be removed in favor of just char_at_reverse() or \
+                         eventually removed altogether")]
     pub fn char_range_at_reverse(&self, start: usize) -> CharRange {
         core_str::StrExt::char_range_at_reverse(&self[..], start)
     }
@@ -2286,8 +2324,12 @@ impl str {
     /// assert_eq!(s.char_at(1), 'b');
     /// assert_eq!(s.char_at(2), 'π');
     /// ```
-    #[unstable(feature = "collections",
-               reason = "naming is uncertain with container conventions")]
+    #[unstable(feature = "str_char",
+               reason = "frequently replaced by the chars() iterator, this \
+                         method may be removed or possibly renamed in the \
+                         future; it is normally replaced by chars/char_indices \
+                         iterators or by getting the first char from a \
+                         subslice")]
     pub fn char_at(&self, i: usize) -> char {
         core_str::StrExt::char_at(&self[..], i)
     }
@@ -2306,8 +2348,10 @@ impl str {
     /// assert_eq!(s.char_at_reverse(1), 'a');
     /// assert_eq!(s.char_at_reverse(2), 'b');
     /// ```
-    #[unstable(feature = "collections",
-               reason = "naming is uncertain with container conventions")]
+    #[unstable(feature = "str_char",
+               reason = "see char_at for more details, but reverse semantics \
+                         are also somewhat unclear, especially with which \
+                         cases generate panics")]
     pub fn char_at_reverse(&self, i: usize) -> char {
         core_str::StrExt::char_at_reverse(&self[..], i)
     }
@@ -2446,8 +2490,10 @@ impl str {
     /// assert_eq!(c, 'ö');
     /// assert_eq!(s2, "we 老虎 Léopard");
     /// ```
-    #[unstable(feature = "collections",
-               reason = "awaiting conventions about shifting and slices")]
+    #[unstable(feature = "str_char",
+               reason = "awaiting conventions about shifting and slices and \
+                         may not be warranted with the existence of the chars \
+                         and/or char_indices iterators")]
     pub fn slice_shift_char(&self) -> Option<(char, &str)> {
         core_str::StrExt::slice_shift_char(&self[..])
     }
@@ -2570,7 +2616,7 @@ impl str {
     ///
     /// assert_eq!(gr2.as_slice(), b);
     /// ```
-    #[unstable(feature = "collections",
+    #[unstable(feature = "unicode",
                reason = "this functionality may only be provided by libunicode")]
     pub fn graphemes(&self, is_extended: bool) -> Graphemes {
         UnicodeStr::graphemes(&self[..], is_extended)
@@ -2587,7 +2633,7 @@ impl str {
     ///
     /// assert_eq!(gr_inds.as_slice(), b);
     /// ```
-    #[unstable(feature = "collections",
+    #[unstable(feature = "unicode",
                reason = "this functionality may only be provided by libunicode")]
     pub fn grapheme_indices(&self, is_extended: bool) -> GraphemeIndices {
         UnicodeStr::grapheme_indices(&self[..], is_extended)
@@ -2621,7 +2667,7 @@ impl str {
     /// `true`, else it should be `false`.
     /// [Unicode Standard Annex #11](http://www.unicode.org/reports/tr11/) recommends that these
     /// characters be treated as 1 column (i.e., `is_cjk = false`) if the locale is unknown.
-    #[unstable(feature = "collections",
+    #[unstable(feature = "unicode",
                reason = "this functionality may only be provided by libunicode")]
     pub fn width(&self, is_cjk: bool) -> usize {
         UnicodeStr::width(&self[..], is_cjk)
diff --git a/src/libcollections/string.rs b/src/libcollections/string.rs
index d2bc98096f6..2a5f8db0496 100644
--- a/src/libcollections/string.rs
+++ b/src/libcollections/string.rs
@@ -29,7 +29,7 @@ use unicode::str as unicode_str;
 use unicode::str::Utf16Item;
 
 use borrow::{Cow, IntoCow};
-use str::{self, CharRange, FromStr, Utf8Error};
+use str::{self, FromStr, Utf8Error};
 use vec::{DerefVec, Vec, as_vec};
 
 /// A growable string stored as a UTF-8 encoded buffer.
@@ -561,9 +561,9 @@ impl String {
             return None
         }
 
-        let CharRange {ch, next} = self.char_range_at_reverse(len);
+        let ch = self.char_at_reverse(len);
         unsafe {
-            self.vec.set_len(next);
+            self.vec.set_len(len - ch.len_utf8());
         }
         Some(ch)
     }
@@ -595,7 +595,8 @@ impl String {
         let len = self.len();
         assert!(idx <= len);
 
-        let CharRange { ch, next } = self.char_range_at(idx);
+        let ch = self.char_at(idx);
+        let next = idx + ch.len_utf8();
         unsafe {
             ptr::copy(self.vec.as_mut_ptr().offset(idx as isize),
                       self.vec.as_ptr().offset(next as isize),
diff --git a/src/libcore/str/mod.rs b/src/libcore/str/mod.rs
index bd46b093b76..6b83338e1d2 100644
--- a/src/libcore/str/mod.rs
+++ b/src/libcore/str/mod.rs
@@ -18,6 +18,7 @@
 
 use self::OldSearcher::{TwoWay, TwoWayLong};
 
+use char::CharExt;
 use clone::Clone;
 use cmp::{self, Eq};
 use default::Default;
@@ -1112,8 +1113,10 @@ static UTF8_CHAR_WIDTH: [u8; 256] = [
 /// the next `char` in a string.  This can be used as a data structure
 /// for iterating over the UTF-8 bytes of a string.
 #[derive(Copy)]
-#[unstable(feature = "core",
-           reason = "naming is uncertain with container conventions")]
+#[unstable(feature = "str_char",
+           reason = "existence of this struct is uncertain as it is frequently \
+                     able to be replaced with char.len_utf8() and/or \
+                     char/char_indices iterators")]
 pub struct CharRange {
     /// Current `char`
     pub ch: char,
@@ -1646,8 +1649,8 @@ impl StrExt for str {
         if self.is_empty() {
             None
         } else {
-            let CharRange {ch, next} = self.char_range_at(0);
-            let next_s = unsafe { self.slice_unchecked(next, self.len()) };
+            let ch = self.char_at(0);
+            let next_s = unsafe { self.slice_unchecked(ch.len_utf8(), self.len()) };
             Some((ch, next_s))
         }
     }
diff --git a/src/libgetopts/lib.rs b/src/libgetopts/lib.rs
index 38abf3881bd..206fdd243c7 100644
--- a/src/libgetopts/lib.rs
+++ b/src/libgetopts/lib.rs
@@ -92,11 +92,10 @@
        html_playground_url = "http://play.rust-lang.org/")]
 
 #![deny(missing_docs)]
-#![feature(collections)]
 #![feature(int_uint)]
 #![feature(staged_api)]
-#![feature(core)]
 #![feature(str_words)]
+#![feature(str_char)]
 #![cfg_attr(test, feature(rustc_private))]
 
 #[cfg(test)] #[macro_use] extern crate log;
@@ -620,8 +619,8 @@ pub fn getopts(args: &[String], optgrps: &[OptGroup]) -> Result {
                 let mut j = 1;
                 names = Vec::new();
                 while j < curlen {
-                    let range = cur.char_range_at(j);
-                    let opt = Short(range.ch);
+                    let ch = cur.char_at(j);
+                    let opt = Short(ch);
 
                     /* In a series of potential options (eg. -aheJ), if we
                        see one which takes an argument, we assume all
@@ -642,12 +641,13 @@ pub fn getopts(args: &[String], optgrps: &[OptGroup]) -> Result {
                         No => false
                     };
 
-                    if arg_follows && range.next < curlen {
-                        i_arg = Some((&cur[range.next..curlen]).to_string());
+                    let next = j + ch.len_utf8();
+                    if arg_follows && next < curlen {
+                        i_arg = Some((&cur[next..curlen]).to_string());
                         break;
                     }
 
-                    j = range.next;
+                    j = next;
                 }
             }
             let mut name_pos = 0;
diff --git a/src/liblibc/lib.rs b/src/liblibc/lib.rs
index 82c54004e99..1e1b128d712 100644
--- a/src/liblibc/lib.rs
+++ b/src/liblibc/lib.rs
@@ -269,8 +269,8 @@ pub mod types {
                 #[repr(C)]
                 #[derive(Copy)] pub struct sockaddr_storage {
                     pub ss_family: sa_family_t,
-                    pub __ss_align: i64,
-                    pub __ss_pad2: [u8; 112],
+                    pub __ss_align: isize,
+                    pub __ss_pad2: [u8; 128 - 2 * (::core::isize::BYTES as usize)],
                 }
                 #[repr(C)]
                 #[derive(Copy)] pub struct sockaddr_in {
diff --git a/src/librustc/lib.rs b/src/librustc/lib.rs
index 60102040bca..97ed391fdfc 100644
--- a/src/librustc/lib.rs
+++ b/src/librustc/lib.rs
@@ -42,6 +42,7 @@
 #![feature(io)]
 #![feature(path_ext)]
 #![feature(str_words)]
+#![feature(str_char)]
 #![cfg_attr(test, feature(test))]
 
 extern crate arena;
diff --git a/src/librustc_driver/lib.rs b/src/librustc_driver/lib.rs
index e132e9833c1..0071e4434ef 100644
--- a/src/librustc_driver/lib.rs
+++ b/src/librustc_driver/lib.rs
@@ -38,6 +38,7 @@
 #![feature(exit_status)]
 #![feature(io)]
 #![feature(set_stdio)]
+#![feature(unicode)]
 
 extern crate arena;
 extern crate flate;
diff --git a/src/librustc_lint/lib.rs b/src/librustc_lint/lib.rs
index a49c9db07a0..99b3393c003 100644
--- a/src/librustc_lint/lib.rs
+++ b/src/librustc_lint/lib.rs
@@ -41,6 +41,7 @@
 #![feature(unsafe_destructor)]
 #![feature(staged_api)]
 #![feature(std_misc)]
+#![feature(str_char)]
 #![cfg_attr(test, feature(test))]
 
 extern crate syntax;
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
index 0d32d7a34e7..45d4a1edc6b 100644
--- a/src/librustc_typeck/check/mod.rs
+++ b/src/librustc_typeck/check/mod.rs
@@ -5240,7 +5240,7 @@ pub fn may_break(cx: &ty::ctxt, id: ast::NodeId, b: &ast::Block) -> bool {
     // inside the loop?
     (loop_query(&*b, |e| {
         match *e {
-            ast::ExprBreak(_) => true,
+            ast::ExprBreak(None) => true,
             _ => false
         }
     })) ||
diff --git a/src/libserialize/lib.rs b/src/libserialize/lib.rs
index 49e44a6d455..31c270dca6b 100644
--- a/src/libserialize/lib.rs
+++ b/src/libserialize/lib.rs
@@ -37,6 +37,7 @@ Core encoding and decoding interfaces.
 #![feature(staged_api)]
 #![feature(std_misc)]
 #![feature(unicode)]
+#![feature(str_char)]
 #![cfg_attr(test, feature(test))]
 
 // test harness access
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index 81e2113cfdf..b055796ba54 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -73,10 +73,10 @@
 //!
 //! ## Concurrency, I/O, and the runtime
 //!
-//! The [`thread`](thread/index.html) module contains Rust's threading abstractions,
-//! while [`comm`](comm/index.html) contains the channel types for message
-//! passing. [`sync`](sync/index.html) contains further, primitive, shared
-//! memory types, including [`atomic`](sync/atomic/index.html).
+//! The [`thread`](thread/index.html) module contains Rust's threading abstractions.
+//! [`sync`](sync/index.html) contains further, primitive, shared memory types,
+//! including [`atomic`](sync/atomic/index.html), and [`mpsc`](sync/mpmc/index.html),
+//! which contains the channel types for message passing.
 //!
 //! Common types of I/O, including files, TCP, UDP, pipes, Unix domain sockets,
 //! timers, and process spawning, are defined in the
@@ -127,6 +127,7 @@
 #![feature(int_uint)]
 #![feature(unique)]
 #![feature(allow_internal_unstable)]
+#![feature(str_char)]
 #![cfg_attr(test, feature(test, rustc_private))]
 
 // Don't link to std. We are std.
diff --git a/src/libstd/net/ip.rs b/src/libstd/net/ip.rs
index c5f2ae53d22..73c2464a6b2 100644
--- a/src/libstd/net/ip.rs
+++ b/src/libstd/net/ip.rs
@@ -202,7 +202,7 @@ impl FromInner<libc::in_addr> for Ipv4Addr {
 impl Ipv6Addr {
     /// Create a new IPv6 address from eight 16-bit segments.
     ///
-    /// The result will represent the IP address a:b:c:d:e:f
+    /// The result will represent the IP address a:b:c:d:e:f:g:h
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn new(a: u16, b: u16, c: u16, d: u16, e: u16, f: u16, g: u16,
                h: u16) -> Ipv6Addr {
diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 657ffcaece9..5c275715352 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -150,7 +150,7 @@ impl PartialEq for Ident {
 
 /// A SyntaxContext represents a chain of macro-expandings
 /// and renamings. Each macro expansion corresponds to
-/// a fresh usize
+/// a fresh u32
 
 // I'm representing this syntax context as an index into
 // a table, in order to work around a compiler bug
@@ -216,6 +216,7 @@ pub struct Lifetime {
 }
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
+/// A lifetime definition, eg `'a: 'b+'c+'d`
 pub struct LifetimeDef {
     pub lifetime: Lifetime,
     pub bounds: Vec<Lifetime>
@@ -251,7 +252,9 @@ pub struct PathSegment {
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub enum PathParameters {
+    /// The `<'a, A,B,C>` in `foo::bar::baz::<'a, A,B,C>`
     AngleBracketedParameters(AngleBracketedParameterData),
+    /// The `(A,B)` and `C` in `Foo(A,B) -> C`
     ParenthesizedParameters(ParenthesizedParameterData),
 }
 
@@ -436,27 +439,37 @@ impl Generics {
     }
 }
 
+/// A `where` clause in a definition
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub struct WhereClause {
     pub id: NodeId,
     pub predicates: Vec<WherePredicate>,
 }
 
+/// A single predicate in a `where` clause
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub enum WherePredicate {
+    /// A type binding, eg `for<'c> Foo: Send+Clone+'c`
     BoundPredicate(WhereBoundPredicate),
+    /// A lifetime predicate, e.g. `'a: 'b+'c`
     RegionPredicate(WhereRegionPredicate),
+    /// An equality predicate (unsupported)
     EqPredicate(WhereEqPredicate)
 }
 
+/// A type bound, eg `for<'c> Foo: Send+Clone+'c`
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub struct WhereBoundPredicate {
     pub span: Span,
+    /// Any lifetimes from a `for` binding
     pub bound_lifetimes: Vec<LifetimeDef>,
+    /// The type being bounded
     pub bounded_ty: P<Ty>,
+    /// Trait and lifetime bounds (`Clone+Send+'static`)
     pub bounds: OwnedSlice<TyParamBound>,
 }
 
+/// A lifetime predicate, e.g. `'a: 'b+'c`
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub struct WhereRegionPredicate {
     pub span: Span,
@@ -464,6 +477,7 @@ pub struct WhereRegionPredicate {
     pub bounds: Vec<Lifetime>,
 }
 
+/// An equality predicate (unsupported), e.g. `T=int`
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub struct WhereEqPredicate {
     pub id: NodeId,
@@ -521,9 +535,13 @@ impl PartialEq for MetaItem_ {
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub struct Block {
+    /// Statements in a block
     pub stmts: Vec<P<Stmt>>,
+    /// An expression at the end of the block
+    /// without a semicolon, if any
     pub expr: Option<P<Expr>>,
     pub id: NodeId,
+    /// Distinguishes between `unsafe { ... }` and `{ ... }`
     pub rules: BlockCheckMode,
     pub span: Span,
 }
@@ -535,9 +553,16 @@ pub struct Pat {
     pub span: Span,
 }
 
+/// A single field in a struct pattern
+///
+/// Patterns like the fields of Foo `{ x, ref y, ref mut z }`
+/// are treated the same as` x: x, y: ref y, z: ref mut z`,
+/// except is_shorthand is true
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub struct FieldPat {
+    /// The identifier for the field
     pub ident: Ident,
+    /// The pattern the field is destructured to
     pub pat: P<Pat>,
     pub is_shorthand: bool,
 }
@@ -574,15 +599,23 @@ pub enum Pat_ {
     /// "None" means a * pattern where we don't bind the fields to names.
     PatEnum(Path, Option<Vec<P<Pat>>>),
 
+    /// Destructuring of a struct, e.g. `Foo {x, y, ..}`
+    /// The `bool` is `true` in the presence of a `..`
     PatStruct(Path, Vec<Spanned<FieldPat>>, bool),
+    /// A tuple pattern `(a, b)`
     PatTup(Vec<P<Pat>>),
+    /// A `box` pattern
     PatBox(P<Pat>),
-    PatRegion(P<Pat>, Mutability), // reference pattern
+    /// A reference pattern, e.g. `&mut (a, b)`
+    PatRegion(P<Pat>, Mutability),
+    /// A literal
     PatLit(P<Expr>),
+    /// A range pattern, e.g. `1...2`
     PatRange(P<Expr>, P<Expr>),
     /// [a, b, ..i, y, z] is represented as:
     ///     PatVec(box [a, b], Some(i), box [y, z])
     PatVec(Vec<P<Pat>>, Option<P<Pat>>, Vec<P<Pat>>),
+    /// A macro pattern; pre-expansion
     PatMac(Mac),
 }
 
@@ -594,23 +627,41 @@ pub enum Mutability {
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
 pub enum BinOp_ {
+    /// The `+` operator (addition)
     BiAdd,
+    /// The `-` operator (subtraction)
     BiSub,
+    /// The `*` operator (multiplication)
     BiMul,
+    /// The `/` operator (division)
     BiDiv,
+    /// The `%` operator (modulus)
     BiRem,
+    /// The `&&` operator (logical and)
     BiAnd,
+    /// The `||` operator (logical or)
     BiOr,
+    /// The `^` operator (bitwise xor)
     BiBitXor,
+    /// The `&` operator (bitwise and)
     BiBitAnd,
+    /// The `|` operator (bitwise or)
     BiBitOr,
+    /// The `<<` operator (shift left)
     BiShl,
+    /// The `>>` operator (shift right)
     BiShr,
+    /// The `==` operator (equality)
     BiEq,
+    /// The `<` operator (less than)
     BiLt,
+    /// The `<=` operator (less than or equal to)
     BiLe,
+    /// The `!=` operator (not equal to)
     BiNe,
+    /// The `>=` operator (greater than or equal to)
     BiGe,
+    /// The `>` operator (greater than)
     BiGt,
 }
 
@@ -618,12 +669,17 @@ pub type BinOp = Spanned<BinOp_>;
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
 pub enum UnOp {
+    /// The `box` operator
     UnUniq,
+    /// The `*` operator for dereferencing
     UnDeref,
+    /// The `!` operator for logical inversion
     UnNot,
+    /// The `-` operator for negation
     UnNeg
 }
 
+/// A statement
 pub type Stmt = Spanned<Stmt_>;
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
@@ -668,6 +724,7 @@ pub enum LocalSource {
 pub struct Local {
     pub pat: P<Pat>,
     pub ty: Option<P<Ty>>,
+    /// Initializer expression to set the value, if any
     pub init: Option<P<Expr>>,
     pub id: NodeId,
     pub span: Span,
@@ -714,6 +771,7 @@ pub enum UnsafeSource {
     UserProvided,
 }
 
+/// An expression
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub struct Expr {
     pub id: NodeId,
@@ -725,34 +783,78 @@ pub struct Expr {
 pub enum Expr_ {
     /// First expr is the place; second expr is the value.
     ExprBox(Option<P<Expr>>, P<Expr>),
+    /// An array (`[a, b, c, d]`)
     ExprVec(Vec<P<Expr>>),
+    /// A function call
+    /// The first field resolves to the function itself,
+    /// and the second field is the list of arguments
     ExprCall(P<Expr>, Vec<P<Expr>>),
+    /// A method call (`x.foo::<Bar, Baz>(a, b, c, d)`)
+    /// The `SpannedIdent` is the identifier for the method name
+    /// The vector of `Ty`s are the ascripted type parameters for the method
+    /// (within the angle brackets)
+    /// The first element of the vector of `Expr`s is the expression that evaluates
+    /// to the object on which the method is being called on (the receiver),
+    /// and the remaining elements are the rest of the arguments.
+    /// Thus, `x.foo::<Bar, Baz>(a, b, c, d)` is represented as
+    /// `ExprMethodCall(foo, [Bar, Baz], [x, a, b, c, d])`
     ExprMethodCall(SpannedIdent, Vec<P<Ty>>, Vec<P<Expr>>),
+    /// A tuple (`(a, b, c ,d)`)
     ExprTup(Vec<P<Expr>>),
+    /// A binary operation (For example: `a + b`, `a * b`)
     ExprBinary(BinOp, P<Expr>, P<Expr>),
+    /// A unary operation (For example: `!x`, `*x`)
     ExprUnary(UnOp, P<Expr>),
+    /// A literal (For example: `1u8`, `"foo"`)
     ExprLit(P<Lit>),
+    /// A cast (`foo as f64`)
     ExprCast(P<Expr>, P<Ty>),
+    /// An `if` block, with an optional else block
+    /// `if expr { block } else { expr }`
     ExprIf(P<Expr>, P<Block>, Option<P<Expr>>),
+    /// An `if let` expression with an optional else block
+    /// `if let pat = expr { block } else { expr }`
+    /// This is desugared to a `match` expression
     ExprIfLet(P<Pat>, P<Expr>, P<Block>, Option<P<Expr>>),
     // FIXME #6993: change to Option<Name> ... or not, if these are hygienic.
+    /// A while loop, with an optional label
+    /// `'label: while expr { block }`
     ExprWhile(P<Expr>, P<Block>, Option<Ident>),
     // FIXME #6993: change to Option<Name> ... or not, if these are hygienic.
+    /// A while-let loop, with an optional label
+    /// `'label: while let pat = expr { block }`
+    /// This is desugared to a combination of `loop` and `match` expressions
     ExprWhileLet(P<Pat>, P<Expr>, P<Block>, Option<Ident>),
     // FIXME #6993: change to Option<Name> ... or not, if these are hygienic.
+    /// A for loop, with an optional label
+    /// `'label: for pat in expr { block }`
+    /// This is desugared to a combination of `loop` and `match` expressions
     ExprForLoop(P<Pat>, P<Expr>, P<Block>, Option<Ident>),
-    // Conditionless loop (can be exited with break, cont, or ret)
+    /// Conditionless loop (can be exited with break, continue, or return)
+    /// `'label: loop { block }`
     // FIXME #6993: change to Option<Name> ... or not, if these are hygienic.
     ExprLoop(P<Block>, Option<Ident>),
+    /// A `match` block, with a source that indicates whether or not it is
+    /// the result of a desugaring, and if so, which kind
     ExprMatch(P<Expr>, Vec<Arm>, MatchSource),
+    /// A closure (for example, `move |a, b, c| {a + b + c}`)
     ExprClosure(CaptureClause, P<FnDecl>, P<Block>),
+    /// A block (`{ ... }`)
     ExprBlock(P<Block>),
 
+    /// An assignment (`a = foo()`)
     ExprAssign(P<Expr>, P<Expr>),
+    /// An assignment with an operator
+    /// For example, `a += 1`
     ExprAssignOp(BinOp, P<Expr>, P<Expr>),
+    /// Access of a named struct field (`obj.foo`)
     ExprField(P<Expr>, SpannedIdent),
+    /// Access of an unnamed field of a struct or tuple-struct
+    /// For example, `foo.0`
     ExprTupField(P<Expr>, Spanned<usize>),
+    /// An indexing operation (`foo[2]`)
     ExprIndex(P<Expr>, P<Expr>),
+    /// A range (`1..2`, `1..`, or `..2`)
     ExprRange(Option<P<Expr>>, Option<P<Expr>>),
 
     /// Variable reference, possibly containing `::` and/or type
@@ -760,20 +862,30 @@ pub enum Expr_ {
     /// e.g. `<Vec<T> as SomeTrait>::SomeType`.
     ExprPath(Option<QSelf>, Path),
 
+    /// A referencing operation (`&a` or `&mut a`)
     ExprAddrOf(Mutability, P<Expr>),
+    /// A `break`, with an optional label to break
     ExprBreak(Option<Ident>),
+    /// A `continue`, with an optional label
     ExprAgain(Option<Ident>),
+    /// A `return`, with an optional value to be returned
     ExprRet(Option<P<Expr>>),
 
+    /// Output of the `asm!()` macro
     ExprInlineAsm(InlineAsm),
 
+    /// A macro invocation; pre-expansion
     ExprMac(Mac),
 
     /// A struct literal expression.
-    ExprStruct(Path, Vec<Field>, Option<P<Expr>> /* base */),
+    /// For example, `Foo {x: 1, y: 2}`, or
+    /// `Foo {x: 1, .. base}`, where `base` is the `Option<Expr>`
+    ExprStruct(Path, Vec<Field>, Option<P<Expr>>),
 
     /// A vector literal constructed from one repeated element.
-    ExprRepeat(P<Expr> /* element */, P<Expr> /* count */),
+    /// For example, `[1u8; 5]`. The first expression is the element
+    /// to be repeated; the second is the number of times to repeat it
+    ExprRepeat(P<Expr>, P<Expr>),
 
     /// No-op: used solely so we can pretty-print faithfully
     ExprParen(P<Expr>)
@@ -880,7 +992,6 @@ pub enum KleeneOp {
 /// The RHS of an MBE macro is the only place `SubstNt`s are substituted.
 /// Nothing special happens to misnamed or misplaced `SubstNt`s.
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
-#[doc="For macro invocations; parsing is delegated to the macro"]
 pub enum TokenTree {
     /// A single token
     TtToken(Span, token::Token),
@@ -991,10 +1102,14 @@ pub enum Mac_ {
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
 pub enum StrStyle {
+    /// A regular string, like `"foo"`
     CookedStr,
+    /// A raw string, like `r##"foo"##`
+    /// The uint is the number of `#` symbols used
     RawStr(usize)
 }
 
+/// A literal
 pub type Lit = Spanned<Lit_>;
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
@@ -1032,13 +1147,21 @@ impl LitIntType {
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub enum Lit_ {
+    /// A string literal (`"foo"`)
     LitStr(InternedString, StrStyle),
+    /// A byte string (`b"foo"`)
     LitBinary(Rc<Vec<u8>>),
+    /// A byte char (`b'f'`)
     LitByte(u8),
+    /// A character literal (`'a'`)
     LitChar(char),
+    /// An integer liteal (`1u8`)
     LitInt(u64, LitIntType),
+    /// A float literal (`1f64` or `1E10f64`)
     LitFloat(InternedString, FloatTy),
+    /// A float literal without a suffix (`1.0 or 1.0E10`)
     LitFloatUnsuffixed(InternedString),
+    /// A boolean literal
     LitBool(bool),
 }
 
@@ -1361,9 +1484,9 @@ impl fmt::Display for Unsafety {
 
 #[derive(Copy, Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash)]
 pub enum ImplPolarity {
-    /// impl Trait for Type
+    /// `impl Trait for Type`
     Positive,
-    /// impl !Trait for Type
+    /// `impl !Trait for Type`
     Negative,
 }
 
@@ -1379,10 +1502,10 @@ impl fmt::Debug for ImplPolarity {
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub enum FunctionRetTy {
-    /// Functions with return type ! that always
+    /// Functions with return type `!`that always
     /// raise an error or exit (i.e. never return to the caller)
     NoReturn(Span),
-    /// Return type is not specified. Functions default to () and
+    /// Return type is not specified. Functions default to `()` and
     /// closures default to inference. Span points to where return
     /// type would be inserted.
     DefaultReturn(Span),
@@ -1438,7 +1561,9 @@ pub struct VariantArg {
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub enum VariantKind {
+    /// Tuple variant, e.g. `Foo(A, B)`
     TupleVariantKind(Vec<VariantArg>),
+    /// Struct variant, e.g. `Foo {x: A, y: B}`
     StructVariantKind(P<StructDef>),
 }
 
@@ -1453,6 +1578,7 @@ pub struct Variant_ {
     pub attrs: Vec<Attribute>,
     pub kind: VariantKind,
     pub id: NodeId,
+    /// Explicit discriminant, eg `Foo = 1`
     pub disr_expr: Option<P<Expr>>,
     pub vis: Visibility,
 }
@@ -1603,6 +1729,9 @@ pub struct StructDef {
   FIXME (#3300): Should allow items to be anonymous. Right now
   we just use dummy names for anon items.
  */
+/// An item
+///
+/// The name might be a dummy name in case of anonymous items
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub struct Item {
     pub ident: Ident,
@@ -1615,19 +1744,27 @@ pub struct Item {
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub enum Item_ {
-    // Optional location (containing arbitrary characters) from which
-    // to fetch the crate sources.
-    // For example, extern crate whatever = "github.com/rust-lang/rust".
+    /// An`extern crate` item, with optional original crate name,
+    /// e.g. `extern crate foo` or `extern crate "foo-bar" as foo`
     ItemExternCrate(Option<(InternedString, StrStyle)>),
+    /// A `use` or `pub use` item
     ItemUse(P<ViewPath>),
 
+    /// A `static` item
     ItemStatic(P<Ty>, Mutability, P<Expr>),
+    /// A `const` item
     ItemConst(P<Ty>, P<Expr>),
+    /// A function declaration
     ItemFn(P<FnDecl>, Unsafety, Abi, Generics, P<Block>),
+    /// A module
     ItemMod(Mod),
+    /// An external module
     ItemForeignMod(ForeignMod),
+    /// A type alias, e.g. `type Foo = Bar<u8>`
     ItemTy(P<Ty>, Generics),
+    /// An enum definition, e.g. `enum Foo<A, B> {C<A>, D<B>}`
     ItemEnum(EnumDef, Generics),
+    /// A struct definition, e.g. `struct Foo<A> {x: A}`
     ItemStruct(P<StructDef>, Generics),
     /// Represents a Trait Declaration
     ItemTrait(Unsafety,
@@ -1636,8 +1773,9 @@ pub enum Item_ {
               Vec<P<TraitItem>>),
 
     // Default trait implementations
-    // `impl Trait for ..`
+    // `impl Trait for .. {}`
     ItemDefaultImpl(Unsafety, TraitRef),
+    /// An implementation, eg `impl<A> Trait for Foo { .. }`
     ItemImpl(Unsafety,
              ImplPolarity,
              Generics,
@@ -1679,10 +1817,14 @@ pub struct ForeignItem {
     pub vis: Visibility,
 }
 
+/// An item within an `extern` block
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub enum ForeignItem_ {
+    /// A foreign function
     ForeignItemFn(P<FnDecl>, Generics),
-    ForeignItemStatic(P<Ty>, /* is_mutbl */ bool),
+    /// A foreign static item (`static ext: u8`), with optional mutability
+    /// (the boolean is true when mutable)
+    ForeignItemStatic(P<Ty>, bool),
 }
 
 impl ForeignItem_ {
diff --git a/src/libsyntax/lib.rs b/src/libsyntax/lib.rs
index b53bb4bc75e..9f217bba00a 100644
--- a/src/libsyntax/lib.rs
+++ b/src/libsyntax/lib.rs
@@ -38,6 +38,7 @@
 #![feature(std_misc)]
 #![feature(unicode)]
 #![feature(path_ext)]
+#![feature(str_char)]
 
 extern crate arena;
 extern crate fmt_macros;
diff --git a/src/libsyntax/parse/lexer/comments.rs b/src/libsyntax/parse/lexer/comments.rs
index fb9e0480ceb..277f5365db3 100644
--- a/src/libsyntax/parse/lexer/comments.rs
+++ b/src/libsyntax/parse/lexer/comments.rs
@@ -20,7 +20,6 @@ use parse::lexer;
 use print::pprust;
 
 use std::io::Read;
-use std::str;
 use std::usize;
 
 #[derive(Clone, Copy, PartialEq)]
@@ -210,11 +209,11 @@ fn all_whitespace(s: &str, col: CharPos) -> Option<usize> {
     let mut col = col.to_usize();
     let mut cursor: usize = 0;
     while col > 0 && cursor < len {
-        let r: str::CharRange = s.char_range_at(cursor);
-        if !r.ch.is_whitespace() {
+        let ch = s.char_at(cursor);
+        if !ch.is_whitespace() {
             return None;
         }
-        cursor = r.next;
+        cursor += ch.len_utf8();
         col -= 1;
     }
     return Some(cursor);
diff --git a/src/libsyntax/parse/lexer/mod.rs b/src/libsyntax/parse/lexer/mod.rs
index d9887c28e5c..bb8f9da8917 100644
--- a/src/libsyntax/parse/lexer/mod.rs
+++ b/src/libsyntax/parse/lexer/mod.rs
@@ -22,7 +22,6 @@ use std::fmt;
 use std::mem::replace;
 use std::num;
 use std::rc::Rc;
-use std::str;
 
 pub use ext::tt::transcribe::{TtReader, new_tt_reader, new_tt_reader_with_doc_flag};
 
@@ -291,7 +290,8 @@ impl<'a> StringReader<'a> {
                           s: &'b str, errmsg: &'b str) -> Cow<'b, str> {
         let mut i = 0;
         while i < s.len() {
-            let str::CharRange { ch, next } = s.char_range_at(i);
+            let ch = s.char_at(i);
+            let next = i + ch.len_utf8();
             if ch == '\r' {
                 if next < s.len() && s.char_at(next) == '\n' {
                     return translate_crlf_(self, start, s, errmsg, i).into_cow();
@@ -309,7 +309,8 @@ impl<'a> StringReader<'a> {
             let mut buf = String::with_capacity(s.len());
             let mut j = 0;
             while i < s.len() {
-                let str::CharRange { ch, next } = s.char_range_at(i);
+                let ch = s.char_at(i);
+                let next = i + ch.len_utf8();
                 if ch == '\r' {
                     if j < i { buf.push_str(&s[j..i]); }
                     j = next;
@@ -335,10 +336,11 @@ impl<'a> StringReader<'a> {
         if current_byte_offset < self.source_text.len() {
             assert!(self.curr.is_some());
             let last_char = self.curr.unwrap();
-            let next = self.source_text.char_range_at(current_byte_offset);
-            let byte_offset_diff = next.next - current_byte_offset;
+            let ch = self.source_text.char_at(current_byte_offset);
+            let next = current_byte_offset + ch.len_utf8();
+            let byte_offset_diff = next - current_byte_offset;
             self.pos = self.pos + Pos::from_usize(byte_offset_diff);
-            self.curr = Some(next.ch);
+            self.curr = Some(ch);
             self.col = self.col + CharPos(1);
             if last_char == '\n' {
                 self.filemap.next_line(self.last_pos);
@@ -370,7 +372,7 @@ impl<'a> StringReader<'a> {
         let offset = self.byte_offset(self.pos).to_usize();
         let s = &self.source_text[..];
         if offset >= s.len() { return None }
-        let str::CharRange { next, .. } = s.char_range_at(offset);
+        let next = offset + s.char_at(offset).len_utf8();
         if next < s.len() {
             Some(s.char_at(next))
         } else {
diff --git a/src/libterm/lib.rs b/src/libterm/lib.rs
index 89960d5d62f..f517dca53cd 100644
--- a/src/libterm/lib.rs
+++ b/src/libterm/lib.rs
@@ -60,6 +60,7 @@
 #![feature(rustc_private)]
 #![feature(staged_api)]
 #![feature(std_misc)]
+#![feature(str_char)]
 #![feature(path_ext)]
 #![cfg_attr(windows, feature(libc))]
 
diff --git a/src/libunicode/u_str.rs b/src/libunicode/u_str.rs
index 917c2d2dfbe..0fbc98ea73c 100644
--- a/src/libunicode/u_str.rs
+++ b/src/libunicode/u_str.rs
@@ -244,7 +244,7 @@ impl<'a> Iterator for Graphemes<'a> {
         }
 
         self.cat = if take_curr {
-            idx = self.string.char_range_at(idx).next;
+            idx = idx + len_utf8(self.string.char_at(idx));
             None
         } else {
             Some(cat)
@@ -256,6 +256,11 @@ impl<'a> Iterator for Graphemes<'a> {
     }
 }
 
+#[cfg(stage0)]
+fn len_utf8(c: char) -> usize { UCharExt::len_utf8(c) }
+#[cfg(not(stage0))]
+fn len_utf8(c: char) -> usize { c.len_utf8() }
+
 impl<'a> DoubleEndedIterator for Graphemes<'a> {
     #[inline]
     fn next_back(&mut self) -> Option<&'a str> {
diff --git a/src/test/compile-fail/loop-labeled-break-value.rs b/src/test/compile-fail/loop-labeled-break-value.rs
new file mode 100644
index 00000000000..e1ae3ae464f
--- /dev/null
+++ b/src/test/compile-fail/loop-labeled-break-value.rs
@@ -0,0 +1,21 @@
+// Copyright 2015 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.
+
+fn main() {
+    loop {
+        let _: i32 = loop { break }; //~ ERROR mismatched types
+    }
+    loop {
+        let _: i32 = 'inner: loop { break 'inner }; //~ ERROR mismatched types
+    }
+    loop {
+        let _: i32 = 'inner: loop { loop { break 'inner } }; //~ ERROR mismatched types
+    }
+}
diff --git a/src/test/run-pass/loop-labeled-break-value.rs b/src/test/run-pass/loop-labeled-break-value.rs
new file mode 100644
index 00000000000..f71dc6869be
--- /dev/null
+++ b/src/test/run-pass/loop-labeled-break-value.rs
@@ -0,0 +1,18 @@
+// Copyright 2015 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.
+
+fn main() {
+    'outer: loop {
+        let _: i32 = loop { break 'outer };
+    }
+    'outer: loop {
+        let _: i32 = loop { loop { break 'outer } };
+    }
+}