diff --git a/doc/rust.md b/doc/rust.md
index 0a33eb6ab2a..3c0828def15 100644
--- a/doc/rust.md
+++ b/doc/rust.md
@@ -802,15 +802,15 @@ Use declarations support a number of convenient shortcuts:
 An example of `use` declarations:
 
 ~~~~
-use std::float::{sin, pow};
-use std::option::Some;
+use std::float::sin;
+use std::option::{Some, None};
 
 fn main() {
-    // Equivalent to 'info!(std::float::pow(std::float::sin(1.0), 2.0));'
-    info!(pow(sin(1.0), 2.0));
+    // Equivalent to 'info!(std::float::sin(1.0));'
+    info!(sin(1.0));
 
-    // Equivalent to 'info!(std::option::Some(1.0));'
-    info!(Some(1.0));
+    // Equivalent to 'info!(~[std::option::Some(1.0), std::option::None]);'
+    info!(~[Some(1.0), None]);
 }
 ~~~~
 
diff --git a/src/compiletest/errors.rs b/src/compiletest/errors.rs
index f524f1424b4..cdc0defcbca 100644
--- a/src/compiletest/errors.rs
+++ b/src/compiletest/errors.rs
@@ -11,7 +11,6 @@
 use core::prelude::*;
 
 use core::io;
-use core::str;
 
 pub struct ExpectedError { line: uint, kind: ~str, msg: ~str }
 
diff --git a/src/compiletest/header.rs b/src/compiletest/header.rs
index 87f5f4bd3fa..2888d4223b7 100644
--- a/src/compiletest/header.rs
+++ b/src/compiletest/header.rs
@@ -16,7 +16,6 @@ use common;
 use core::iterator::IteratorUtil;
 use core::io;
 use core::os;
-use core::str;
 
 pub struct TestProps {
     // Lines that should be expected, in order, on standard out
diff --git a/src/libextra/net_url.rs b/src/libextra/net_url.rs
index c85a866a04a..83cda31c680 100644
--- a/src/libextra/net_url.rs
+++ b/src/libextra/net_url.rs
@@ -19,7 +19,6 @@ use core::cmp::Eq;
 use core::io::{Reader, ReaderUtil};
 use core::io;
 use core::hashmap::HashMap;
-use core::str;
 use core::to_bytes;
 use core::uint;
 
@@ -394,7 +393,7 @@ enum Input {
 // returns userinfo, host, port, and unparsed part, or an error
 fn get_authority(rawurl: &str) ->
     Result<(Option<UserInfo>, ~str, Option<~str>, ~str), ~str> {
-    if !raw_url.starts_with("//") {
+    if !rawurl.starts_with("//") {
         // there is no authority.
         return Ok((None, ~"", None, rawurl.to_str()));
     }
diff --git a/src/libextra/rope.rs b/src/libextra/rope.rs
index f23a4433289..de549641423 100644
--- a/src/libextra/rope.rs
+++ b/src/libextra/rope.rs
@@ -40,6 +40,7 @@ use core::prelude::*;
 use core::iterator::IteratorUtil;
 use core::uint;
 use core::vec;
+use core::str;
 
 /// The type of ropes.
 pub type Rope = node::Root;
@@ -1187,8 +1188,6 @@ pub mod node {
     pub mod char_iterator {
         use core::prelude::*;
 
-        use core::str;
-
         use rope::node::{Leaf, Node};
         use rope::node::leaf_iterator;
 
diff --git a/src/libextra/semver.rs b/src/libextra/semver.rs
index c7d2010e609..3ab8bb1f60b 100644
--- a/src/libextra/semver.rs
+++ b/src/libextra/semver.rs
@@ -20,7 +20,6 @@ use core::cmp;
 use core::io::{ReaderUtil};
 use core::io;
 use core::option::{Option, Some, None};
-use core::str;
 use core::to_str::ToStr;
 use core::uint;
 
diff --git a/src/libfuzzer/fuzzer.rc b/src/libfuzzer/fuzzer.rc
index 416fabb6d8f..dbeea417a3d 100644
--- a/src/libfuzzer/fuzzer.rc
+++ b/src/libfuzzer/fuzzer.rc
@@ -37,7 +37,6 @@ use std::result;
 use std::run;
 use std::str;
 use std::uint;
-use std::vec;
 
 use syntax::diagnostic;
 use syntax::parse::token::ident_interner;
diff --git a/src/librustc/middle/trans/base.rs b/src/librustc/middle/trans/base.rs
index b913a1b4996..8e015d9a677 100644
--- a/src/librustc/middle/trans/base.rs
+++ b/src/librustc/middle/trans/base.rs
@@ -1995,7 +1995,7 @@ pub fn trans_enum_variant(ccx: @CrateContext,
 
     debug!("trans_enum_variant: name=%s tps=%s repr=%? enum_ty=%s",
            unsafe { str::raw::from_c_str(llvm::LLVMGetValueName(llfndecl)) },
-           ~"[" + ty_param_substs.map(|&t| ty_to_str(ccx.tcx.connect(t)), ", ") + "]",
+           ~"[" + ty_param_substs.map(|&t| ty_to_str(ccx.tcx, t)).connect(", ") + "]",
            repr, ty_to_str(ccx.tcx, enum_ty));
 
     adt::trans_start_init(bcx, repr, fcx.llretptr.get(), disr);
diff --git a/src/librustc/middle/trans/build.rs b/src/librustc/middle/trans/build.rs
index 8406444bd09..8b281487504 100644
--- a/src/librustc/middle/trans/build.rs
+++ b/src/librustc/middle/trans/build.rs
@@ -192,9 +192,7 @@ pub fn Invoke(cx: block,
     terminate(cx, "Invoke");
     debug!("Invoke(%s with arguments (%s))",
            val_str(cx.ccx().tn, Fn),
-           vec::map(Args.connect(|a| val_str(cx.ccx().tn,
-                                                   *a).to_owned()),
-                        ", "));
+           Args.map(|a| val_str(cx.ccx().tn, *a).to_owned()).connect(", "));
     unsafe {
         count_insn(cx, "invoke");
         llvm::LLVMBuildInvoke(B(cx),
diff --git a/src/librustc/middle/typeck/check/mod.rs b/src/librustc/middle/typeck/check/mod.rs
index 30dd677396b..b12b1499759 100644
--- a/src/librustc/middle/typeck/check/mod.rs
+++ b/src/librustc/middle/typeck/check/mod.rs
@@ -115,7 +115,6 @@ use core::iterator::IteratorUtil;
 use core::cast::transmute;
 use core::hashmap::HashMap;
 use core::result;
-use core::str;
 use core::util::replace;
 use core::vec;
 use extra::list::Nil;
diff --git a/src/librustc/middle/typeck/infer/to_str.rs b/src/librustc/middle/typeck/infer/to_str.rs
index d6623f06c3d..364d8b2d052 100644
--- a/src/librustc/middle/typeck/infer/to_str.rs
+++ b/src/librustc/middle/typeck/infer/to_str.rs
@@ -18,7 +18,6 @@ use middle::typeck::infer::InferCtxt;
 use middle::typeck::infer::unify::{Redirect, Root, VarValue};
 use util::ppaux::{mt_to_str, ty_to_str, trait_ref_to_str};
 
-use core::str;
 use core::uint;
 use syntax::ast;
 
diff --git a/src/librustc/util/common.rs b/src/librustc/util/common.rs
index 8d0cba0e8b7..9556fd3e257 100644
--- a/src/librustc/util/common.rs
+++ b/src/librustc/util/common.rs
@@ -16,7 +16,6 @@ use syntax::visit;
 
 use core::hashmap::HashSet;
 use core::io;
-use core::str;
 use extra;
 
 pub fn time<T>(do_it: bool, what: ~str, thunk: &fn() -> T) -> T {
diff --git a/src/librustpkg/version.rs b/src/librustpkg/version.rs
index 434583eb79e..0900d93e498 100644
--- a/src/librustpkg/version.rs
+++ b/src/librustpkg/version.rs
@@ -143,7 +143,7 @@ fn try_parsing_version(s: &str) -> Option<Version> {
     let s = s.trim();
     debug!("Attempting to parse: %s", s);
     let mut parse_state = Start;
-    for s.iter().advance |&c| {
+    for s.iter().advance |c| {
         if char::is_digit(c) {
             parse_state = SawDigit;
         }
@@ -171,7 +171,7 @@ fn is_url_like(p: &RemotePath) -> bool {
 /// Otherwise, return None.
 pub fn split_version<'a>(s: &'a str) -> Option<(&'a str, Version)> {
     // reject strings with multiple '#'s
-    if s.splitn_iter('#', 2).count() > 1 {
+    if s.splitn_iter('#', 2).count() > 2 {
         return None;
     }
     match s.rfind('#') {
diff --git a/src/libstd/io.rs b/src/libstd/io.rs
index 409882c5cfe..58711360c35 100644
--- a/src/libstd/io.rs
+++ b/src/libstd/io.rs
@@ -1836,7 +1836,6 @@ mod tests {
     use io;
     use path::Path;
     use result;
-    use str;
     use u64;
     use vec;
 
diff --git a/src/libstd/str.rs b/src/libstd/str.rs
index e581eff83ad..8cd69f32e49 100644
--- a/src/libstd/str.rs
+++ b/src/libstd/str.rs
@@ -1800,7 +1800,7 @@ impl<'self> StrSlice<'self> for &'self str {
      */
     #[inline]
     fn substr(&self, begin: uint, n: uint) -> &'self str {
-        s.slice(begin, begin + count_bytes(s, begin, n))
+        self.slice(begin, begin + count_bytes(*self, begin, n))
     }
     /// Escape each char in `s` with char::escape_default.
     #[inline]
@@ -2318,7 +2318,6 @@ impl<'self> Iterator<u8> for StrBytesRevIterator<'self> {
 mod tests {
     use iterator::IteratorUtil;
     use container::Container;
-    use char;
     use option::Some;
     use libc::c_char;
     use libc;
@@ -3026,14 +3025,6 @@ mod tests {
         assert_eq!(~"YMCA", map("ymca", |c| unsafe {libc::toupper(c as c_char)} as char));
     }
 
-    #[test]
-    fn test_chars() {
-        let ss = ~"ศไทย中华Việt Nam";
-        assert!(~['ศ','ไ','ท','ย','中','华','V','i','ệ','t',' ','N','a',
-                       'm']
-            == to_chars(ss));
-    }
-
     #[test]
     fn test_utf16() {
         let pairs =
diff --git a/src/libstd/str/ascii.rs b/src/libstd/str/ascii.rs
index a4a1b7a171d..618d5095777 100644
--- a/src/libstd/str/ascii.rs
+++ b/src/libstd/str/ascii.rs
@@ -202,7 +202,6 @@ impl ToStrConsume for ~[Ascii] {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use str;
 
     macro_rules! v2ascii (
         ( [$($e:expr),*]) => ( [$(Ascii{chr:$e}),*]);
diff --git a/src/libsyntax/ast_map.rs b/src/libsyntax/ast_map.rs
index 8a379a6213a..2e60f7d02df 100644
--- a/src/libsyntax/ast_map.rs
+++ b/src/libsyntax/ast_map.rs
@@ -24,7 +24,6 @@ use syntax::parse::token::special_idents;
 
 use core::cmp;
 use core::hashmap::HashMap;
-use core::str;
 use core::vec;
 
 pub enum path_elt {
diff --git a/src/libsyntax/ast_util.rs b/src/libsyntax/ast_util.rs
index db7c29edab0..3d6269942fd 100644
--- a/src/libsyntax/ast_util.rs
+++ b/src/libsyntax/ast_util.rs
@@ -23,7 +23,6 @@ use visit;
 use core::hashmap::HashMap;
 use core::int;
 use core::option;
-use core::str;
 use core::to_bytes;
 
 pub fn path_name_i(idents: &[ident]) -> ~str {
diff --git a/src/libsyntax/ext/asm.rs b/src/libsyntax/ext/asm.rs
index 14cbd170c48..d3efd07aa04 100644
--- a/src/libsyntax/ext/asm.rs
+++ b/src/libsyntax/ext/asm.rs
@@ -21,7 +21,6 @@ use ext::base::*;
 use parse;
 use parse::token;
 
-use core::str;
 use core::vec;
 
 enum State {
diff --git a/src/libsyntax/ext/pipes/liveness.rs b/src/libsyntax/ext/pipes/liveness.rs
index cb7386b9880..1076c5d0b98 100644
--- a/src/libsyntax/ext/pipes/liveness.rs
+++ b/src/libsyntax/ext/pipes/liveness.rs
@@ -42,7 +42,6 @@ use core::prelude::*;
 use ext::base::ExtCtxt;
 use ext::pipes::proto::{protocol_};
 
-use core::str;
 use extra::bitv::Bitv;
 
 pub fn analyze(proto: @mut protocol_, _cx: @ExtCtxt) {
diff --git a/src/libsyntax/ext/tt/macro_parser.rs b/src/libsyntax/ext/tt/macro_parser.rs
index 0c9ca98fb9d..e5a77cc21fb 100644
--- a/src/libsyntax/ext/tt/macro_parser.rs
+++ b/src/libsyntax/ext/tt/macro_parser.rs
@@ -24,7 +24,6 @@ use parse::token;
 
 use core::iterator::IteratorUtil;
 use core::hashmap::HashMap;
-use core::str;
 use core::uint;
 use core::vec;
 
@@ -371,14 +370,14 @@ pub fn parse(
         } else {
             if (bb_eis.len() > 0u && next_eis.len() > 0u)
                 || bb_eis.len() > 1u {
-                let nts = vec::map(bb_eis.connect(|ei| {
+                let nts = bb_eis.map(|ei| {
                     match ei.elts[ei.idx].node {
                       match_nonterminal(ref bind,ref name,_) => {
                         fmt!("%s ('%s')", *ident_to_str(name),
                              *ident_to_str(bind))
                       }
                       _ => fail!()
-                    } }), " or ");
+                    } }).connect(" or ");
                 return error(sp, fmt!(
                     "Local ambiguity: multiple parsing options: \
                      built-in NTs %s or %u other options.",
diff --git a/src/test/run-pass/trait-to-str.rs b/src/test/run-pass/trait-to-str.rs
index bc167e5124f..4029bd18338 100644
--- a/src/test/run-pass/trait-to-str.rs
+++ b/src/test/run-pass/trait-to-str.rs
@@ -14,7 +14,8 @@
 
 extern mod std;
 
-use std::{str, int, vec};
+use std::str::StrVector;
+use std::{int, vec};
 
 trait to_str {
     fn to_str(&self) -> ~str;
@@ -26,7 +27,7 @@ impl to_str for int {
 
 impl<T:to_str> to_str for ~[T] {
     fn to_str(&self) -> ~str {
-        ~"[" + self.map(|e| e.to_str()).connect(", ") + "]"
+        ~"[" + vec::map(*self, |e| e.to_str()).connect(", ") + "]"
     }
 }