diff --git a/src/libstd/fs/mod.rs b/src/libstd/fs/mod.rs
index ac1f5993aa1..d072d1f102b 100644
--- a/src/libstd/fs/mod.rs
+++ b/src/libstd/fs/mod.rs
@@ -124,7 +124,7 @@ impl File {
     /// This function will return an error if `path` does not already exist.
     /// Other errors may also be returned according to `OpenOptions::open`.
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn open<P: AsPath + ?Sized>(path: &P) -> io::Result<File> {
+    pub fn open<P: AsPath>(path: P) -> io::Result<File> {
         OpenOptions::new().read(true).open(path)
     }
 
@@ -135,7 +135,7 @@ impl File {
     ///
     /// See the `OpenOptions::open` function for more details.
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn create<P: AsPath + ?Sized>(path: &P) -> io::Result<File> {
+    pub fn create<P: AsPath>(path: P) -> io::Result<File> {
         OpenOptions::new().write(true).create(true).truncate(true).open(path)
     }
 
@@ -297,7 +297,7 @@ impl OpenOptions {
     ///   permissions for
     /// * Filesystem-level errors (full disk, etc)
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn open<P: AsPath + ?Sized>(&self, path: &P) -> io::Result<File> {
+    pub fn open<P: AsPath>(&self, path: P) -> io::Result<File> {
         let path = path.as_path();
         let inner = try!(fs_imp::File::open(path, &self.0));
         Ok(File { path: path.to_path_buf(), inner: inner })
@@ -410,7 +410,7 @@ impl DirEntry {
 /// user lacks permissions to remove the file, or if some other filesystem-level
 /// error occurs.
 #[stable(feature = "rust1", since = "1.0.0")]
-pub fn remove_file<P: AsPath + ?Sized>(path: &P) -> io::Result<()> {
+pub fn remove_file<P: AsPath>(path: P) -> io::Result<()> {
     fs_imp::unlink(path.as_path())
 }
 
@@ -438,7 +438,7 @@ pub fn remove_file<P: AsPath + ?Sized>(path: &P) -> io::Result<()> {
 /// permissions to perform a `metadata` call on the given `path` or if there
 /// is no entry in the filesystem at the provided path.
 #[stable(feature = "rust1", since = "1.0.0")]
-pub fn metadata<P: AsPath + ?Sized>(path: &P) -> io::Result<Metadata> {
+pub fn metadata<P: AsPath>(path: P) -> io::Result<Metadata> {
     fs_imp::stat(path.as_path()).map(Metadata)
 }
 
@@ -459,8 +459,7 @@ pub fn metadata<P: AsPath + ?Sized>(path: &P) -> io::Result<Metadata> {
 /// reside on separate filesystems, or if some other intermittent I/O error
 /// occurs.
 #[stable(feature = "rust1", since = "1.0.0")]
-pub fn rename<P: AsPath + ?Sized, Q: AsPath + ?Sized>(from: &P, to: &Q)
-                                                      -> io::Result<()> {
+pub fn rename<P: AsPath, Q: AsPath>(from: P, to: Q) -> io::Result<()> {
     fs_imp::rename(from.as_path(), to.as_path())
 }
 
@@ -490,9 +489,9 @@ pub fn rename<P: AsPath + ?Sized, Q: AsPath + ?Sized>(from: &P, to: &Q)
 /// * The current process does not have the permission rights to access
 ///   `from` or write `to`
 #[stable(feature = "rust1", since = "1.0.0")]
-pub fn copy<P: AsPath + ?Sized, Q: AsPath + ?Sized>(from: &P, to: &Q)
-                                                    -> io::Result<u64> {
+pub fn copy<P: AsPath, Q: AsPath>(from: P, to: Q) -> io::Result<u64> {
     let from = from.as_path();
+    let to = to.as_path();
     if !from.is_file() {
         return Err(Error::new(ErrorKind::MismatchedFileTypeForOperation,
                               "the source path is not an existing file",
@@ -513,8 +512,7 @@ pub fn copy<P: AsPath + ?Sized, Q: AsPath + ?Sized>(from: &P, to: &Q)
 /// The `dst` path will be a link pointing to the `src` path. Note that systems
 /// often require these two paths to both be located on the same filesystem.
 #[stable(feature = "rust1", since = "1.0.0")]
-pub fn hard_link<P: AsPath + ?Sized, Q: AsPath + ?Sized>(src: &P, dst: &Q)
-                                                         -> io::Result<()> {
+pub fn hard_link<P: AsPath, Q: AsPath>(src: P, dst: Q) -> io::Result<()> {
     fs_imp::link(src.as_path(), dst.as_path())
 }
 
@@ -522,8 +520,7 @@ pub fn hard_link<P: AsPath + ?Sized, Q: AsPath + ?Sized>(src: &P, dst: &Q)
 ///
 /// The `dst` path will be a soft link pointing to the `src` path.
 #[stable(feature = "rust1", since = "1.0.0")]
-pub fn soft_link<P: AsPath + ?Sized, Q: AsPath + ?Sized>(src: &P, dst: &Q)
-                                                         -> io::Result<()> {
+pub fn soft_link<P: AsPath, Q: AsPath>(src: P, dst: Q) -> io::Result<()> {
     fs_imp::symlink(src.as_path(), dst.as_path())
 }
 
@@ -535,7 +532,7 @@ pub fn soft_link<P: AsPath + ?Sized, Q: AsPath + ?Sized>(src: &P, dst: &Q)
 /// reading a file that does not exist or reading a file that is not a soft
 /// link.
 #[stable(feature = "rust1", since = "1.0.0")]
-pub fn read_link<P: AsPath + ?Sized>(path: &P) -> io::Result<PathBuf> {
+pub fn read_link<P: AsPath>(path: P) -> io::Result<PathBuf> {
     fs_imp::readlink(path.as_path())
 }
 
@@ -554,7 +551,7 @@ pub fn read_link<P: AsPath + ?Sized>(path: &P) -> io::Result<PathBuf> {
 /// This function will return an error if the user lacks permissions to make a
 /// new directory at the provided `path`, or if the directory already exists.
 #[stable(feature = "rust1", since = "1.0.0")]
-pub fn create_dir<P: AsPath + ?Sized>(path: &P) -> io::Result<()> {
+pub fn create_dir<P: AsPath>(path: P) -> io::Result<()> {
     fs_imp::mkdir(path.as_path())
 }
 
@@ -568,7 +565,7 @@ pub fn create_dir<P: AsPath + ?Sized>(path: &P) -> io::Result<()> {
 /// error conditions for when a directory is being created (after it is
 /// determined to not exist) are outlined by `fs::create_dir`.
 #[stable(feature = "rust1", since = "1.0.0")]
-pub fn create_dir_all<P: AsPath + ?Sized>(path: &P) -> io::Result<()> {
+pub fn create_dir_all<P: AsPath>(path: P) -> io::Result<()> {
     let path = path.as_path();
     if path.is_dir() { return Ok(()) }
     if let Some(p) = path.parent() { try!(create_dir_all(p)) }
@@ -590,7 +587,7 @@ pub fn create_dir_all<P: AsPath + ?Sized>(path: &P) -> io::Result<()> {
 /// This function will return an error if the user lacks permissions to remove
 /// the directory at the provided `path`, or if the directory isn't empty.
 #[stable(feature = "rust1", since = "1.0.0")]
-pub fn remove_dir<P: AsPath + ?Sized>(path: &P) -> io::Result<()> {
+pub fn remove_dir<P: AsPath>(path: P) -> io::Result<()> {
     fs_imp::rmdir(path.as_path())
 }
 
@@ -604,7 +601,7 @@ pub fn remove_dir<P: AsPath + ?Sized>(path: &P) -> io::Result<()> {
 ///
 /// See `file::remove_file` and `fs::remove_dir`
 #[stable(feature = "rust1", since = "1.0.0")]
-pub fn remove_dir_all<P: AsPath + ?Sized>(path: &P) -> io::Result<()> {
+pub fn remove_dir_all<P: AsPath>(path: P) -> io::Result<()> {
     let path = path.as_path();
     for child in try!(read_dir(path)) {
         let child = try!(child).path();
@@ -657,7 +654,7 @@ pub fn remove_dir_all<P: AsPath + ?Sized>(path: &P) -> io::Result<()> {
 /// the process lacks permissions to view the contents or if the `path` points
 /// at a non-directory file
 #[stable(feature = "rust1", since = "1.0.0")]
-pub fn read_dir<P: AsPath + ?Sized>(path: &P) -> io::Result<ReadDir> {
+pub fn read_dir<P: AsPath>(path: P) -> io::Result<ReadDir> {
     fs_imp::readdir(path.as_path()).map(ReadDir)
 }
 
@@ -673,7 +670,7 @@ pub fn read_dir<P: AsPath + ?Sized>(path: &P) -> io::Result<ReadDir> {
            reason = "the precise semantics and defaults for a recursive walk \
                      may change and this may end up accounting for files such \
                      as symlinks differently")]
-pub fn walk_dir<P: AsPath + ?Sized>(path: &P) -> io::Result<WalkDir> {
+pub fn walk_dir<P: AsPath>(path: P) -> io::Result<WalkDir> {
     let start = try!(read_dir(path));
     Ok(WalkDir { cur: Some(start), stack: Vec::new() })
 }
@@ -759,8 +756,8 @@ impl PathExt for Path {
            reason = "the argument type of u64 is not quite appropriate for \
                      this function and may change if the standard library \
                      gains a type to represent a moment in time")]
-pub fn set_file_times<P: AsPath + ?Sized>(path: &P, accessed: u64,
-                                          modified: u64) -> io::Result<()> {
+pub fn set_file_times<P: AsPath>(path: P, accessed: u64,
+                                 modified: u64) -> io::Result<()> {
     fs_imp::utimes(path.as_path(), accessed, modified)
 }
 
@@ -788,8 +785,7 @@ pub fn set_file_times<P: AsPath + ?Sized>(path: &P, accessed: u64,
            reason = "a more granual ability to set specific permissions may \
                      be exposed on the Permissions structure itself and this \
                      method may not always exist")]
-pub fn set_permissions<P: AsPath + ?Sized>(path: &P, perm: Permissions)
-                                           -> io::Result<()> {
+pub fn set_permissions<P: AsPath>(path: P, perm: Permissions) -> io::Result<()> {
     fs_imp::set_perm(path.as_path(), perm.0)
 }
 
diff --git a/src/libstd/path.rs b/src/libstd/path.rs
index 829aaadaeb2..3082e63b818 100644
--- a/src/libstd/path.rs
+++ b/src/libstd/path.rs
@@ -877,7 +877,7 @@ impl PathBuf {
     /// Allocate a `PathBuf` with initial contents given by the
     /// argument.
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn new<S: ?Sized + AsOsStr>(s: &S) -> PathBuf {
+    pub fn new<S: AsOsStr>(s: S) -> PathBuf {
         PathBuf { inner: s.as_os_str().to_os_string() }
     }
 
@@ -891,7 +891,7 @@ impl PathBuf {
     ///   replaces everything except for the prefix (if any) of `self`.
     /// * if `path` has a prefix but no root, it replaces `self.
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn push<P: ?Sized>(&mut self, path: &P) where P: AsPath {
+    pub fn push<P: AsPath>(&mut self, path: P) {
         let path = path.as_path();
 
         // in general, a separator is needed if the rightmost byte is not a separator
@@ -959,7 +959,7 @@ impl PathBuf {
     /// assert!(buf == PathBuf::new("/baz.txt"));
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn set_file_name<S: ?Sized>(&mut self, file_name: &S) where S: AsOsStr {
+    pub fn set_file_name<S: AsOsStr>(&mut self, file_name: S) {
         if self.file_name().is_some() {
             let popped = self.pop();
             debug_assert!(popped);
@@ -974,7 +974,7 @@ impl PathBuf {
     /// Otherwise, returns `true`; if `self.extension()` is `None`, the extension
     /// is added; otherwise it is replaced.
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn set_extension<S: ?Sized + AsOsStr>(&mut self, extension: &S) -> bool {
+    pub fn set_extension<S: AsOsStr>(&mut self, extension: S) -> bool {
         if self.file_name().is_none() { return false; }
 
         let mut stem = match self.file_stem() {
@@ -1000,8 +1000,8 @@ impl PathBuf {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<'a, P: ?Sized + 'a> iter::FromIterator<&'a P> for PathBuf where P: AsPath {
-    fn from_iter<I: IntoIterator<Item = &'a P>>(iter: I) -> PathBuf {
+impl<P: AsPath> iter::FromIterator<P> for PathBuf {
+    fn from_iter<I: IntoIterator<Item = P>>(iter: I) -> PathBuf {
         let mut buf = PathBuf::new("");
         buf.extend(iter);
         buf
@@ -1009,8 +1009,8 @@ impl<'a, P: ?Sized + 'a> iter::FromIterator<&'a P> for PathBuf where P: AsPath {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<'a, P: ?Sized + 'a> iter::Extend<&'a P> for PathBuf where P: AsPath {
-    fn extend<I: IntoIterator<Item = &'a P>>(&mut self, iter: I) {
+impl<P: AsPath> iter::Extend<P> for PathBuf {
+    fn extend<I: IntoIterator<Item = P>>(&mut self, iter: I) {
         for p in iter {
             self.push(p)
         }
@@ -1253,13 +1253,13 @@ impl Path {
 
     /// Determines whether `base` is a prefix of `self`.
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn starts_with<P: ?Sized>(&self, base: &P) -> bool where P: AsPath {
+    pub fn starts_with<P: AsPath>(&self, base: P) -> bool {
         iter_after(self.components(), base.as_path().components()).is_some()
     }
 
     /// Determines whether `child` is a suffix of `self`.
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn ends_with<P: ?Sized>(&self, child: &P) -> bool where P: AsPath {
+    pub fn ends_with<P: AsPath>(&self, child: P) -> bool {
         iter_after(self.components().rev(), child.as_path().components().rev()).is_some()
     }
 
@@ -1293,7 +1293,7 @@ impl Path {
     ///
     /// See `PathBuf::push` for more details on what it means to adjoin a path.
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn join<P: ?Sized>(&self, path: &P) -> PathBuf where P: AsPath {
+    pub fn join<P: AsPath>(&self, path: P) -> PathBuf {
         let mut buf = self.to_path_buf();
         buf.push(path);
         buf
@@ -1303,7 +1303,7 @@ impl Path {
     ///
     /// See `PathBuf::set_file_name` for more details.
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn with_file_name<S: ?Sized>(&self, file_name: &S) -> PathBuf where S: AsOsStr {
+    pub fn with_file_name<S: AsOsStr>(&self, file_name: S) -> PathBuf {
         let mut buf = self.to_path_buf();
         buf.set_file_name(file_name);
         buf
@@ -1313,7 +1313,7 @@ impl Path {
     ///
     /// See `PathBuf::set_extension` for more details.
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn with_extension<S: ?Sized>(&self, extension: &S) -> PathBuf where S: AsOsStr {
+    pub fn with_extension<S: AsOsStr>(&self, extension: S) -> PathBuf {
         let mut buf = self.to_path_buf();
         buf.set_extension(extension);
         buf
diff --git a/src/libstd/process.rs b/src/libstd/process.rs
index ebd0820669c..c344cbe0862 100644
--- a/src/libstd/process.rs
+++ b/src/libstd/process.rs
@@ -147,7 +147,7 @@ impl Command {
     /// Builder methods are provided to change these defaults and
     /// otherwise configure the process.
     #[stable(feature = "process", since = "1.0.0")]
-    pub fn new<S: AsOsStr + ?Sized>(program: &S) -> Command {
+    pub fn new<S: AsOsStr>(program: S) -> Command {
         Command {
             inner: CommandImp::new(program.as_os_str()),
             stdin: None,
@@ -158,7 +158,7 @@ impl Command {
 
     /// Add an argument to pass to the program.
     #[stable(feature = "process", since = "1.0.0")]
-    pub fn arg<S: AsOsStr + ?Sized>(&mut self, arg: &S) -> &mut Command {
+    pub fn arg<S: AsOsStr>(&mut self, arg: S) -> &mut Command {
         self.inner.arg(arg.as_os_str());
         self
     }
@@ -175,7 +175,7 @@ impl Command {
     /// Note that environment variable names are case-insensitive (but case-preserving) on Windows,
     /// and case-sensitive on all other platforms.
     #[stable(feature = "process", since = "1.0.0")]
-    pub fn env<K: ?Sized, V: ?Sized>(&mut self, key: &K, val: &V) -> &mut Command
+    pub fn env<K, V>(&mut self, key: K, val: V) -> &mut Command
         where K: AsOsStr, V: AsOsStr
     {
         self.inner.env(key.as_os_str(), val.as_os_str());
@@ -184,7 +184,7 @@ impl Command {
 
     /// Removes an environment variable mapping.
     #[stable(feature = "process", since = "1.0.0")]
-    pub fn env_remove<K: ?Sized + AsOsStr>(&mut self, key: &K) -> &mut Command {
+    pub fn env_remove<K: AsOsStr>(&mut self, key: K) -> &mut Command {
         self.inner.env_remove(key.as_os_str());
         self
     }
@@ -198,7 +198,7 @@ impl Command {
 
     /// Set the working directory for the child process.
     #[stable(feature = "process", since = "1.0.0")]
-    pub fn current_dir<P: AsPath + ?Sized>(&mut self, dir: &P) -> &mut Command {
+    pub fn current_dir<P: AsPath>(&mut self, dir: P) -> &mut Command {
         self.inner.cwd(dir.as_path().as_os_str());
         self
     }
diff --git a/src/libstd/sys/unix/os.rs b/src/libstd/sys/unix/os.rs
index d332556d188..b0ad9ab6937 100644
--- a/src/libstd/sys/unix/os.rs
+++ b/src/libstd/sys/unix/os.rs
@@ -253,7 +253,7 @@ pub fn current_exe() -> io::Result<PathBuf> {
         let err = _NSGetExecutablePath(v.as_mut_ptr() as *mut i8, &mut sz);
         if err != 0 { return Err(io::Error::last_os_error()); }
         v.set_len(sz as uint - 1); // chop off trailing NUL
-        Ok(PathBuf::new::<OsString>(&OsStringExt::from_vec(v)))
+        Ok(PathBuf::new(OsString::from_vec(v)))
     }
 }