librustc: Remove ~EXPR, ~TYPE, and ~PAT from the language, except

for `~str`/`~[]`.

Note that `~self` still remains, since I forgot to add support for
`Box<self>` before the snapshot.

How to update your code:

* Instead of `~EXPR`, you should write `box EXPR`.

* Instead of `~TYPE`, you should write `Box<Type>`.

* Instead of `~PATTERN`, you should write `box PATTERN`.

[breaking-change]

src/libnative/io/pipe_unix.rs

@@ -144,8 +144,10 @@ impl rtio::RtioPipe for UnixStream {
         }
     }
 
-    fn clone(&self) -> ~rtio::RtioPipe:Send {
-        box UnixStream { inner: self.inner.clone() } as ~rtio::RtioPipe:Send
+    fn clone(&self) -> Box<rtio::RtioPipe:Send> {
+        box UnixStream {
+            inner: self.inner.clone(),
+        } as Box<rtio::RtioPipe:Send>
     }
 }
 
@@ -176,8 +178,10 @@ impl UnixListener {
 }
 
 impl rtio::RtioUnixListener for UnixListener {
-    fn listen(~self) -> IoResult<~rtio::RtioUnixAcceptor:Send> {
-        self.native_listen(128).map(|a| box a as ~rtio::RtioUnixAcceptor:Send)
+    fn listen(~self) -> IoResult<Box<rtio::RtioUnixAcceptor:Send>> {
+        self.native_listen(128).map(|a| {
+            box a as Box<rtio::RtioUnixAcceptor:Send>
+        })
     }
 }
 
@@ -209,8 +213,8 @@ impl UnixAcceptor {
 }
 
 impl rtio::RtioUnixAcceptor for UnixAcceptor {
-    fn accept(&mut self) -> IoResult<~rtio::RtioPipe:Send> {
-        self.native_accept().map(|s| box s as ~rtio::RtioPipe:Send)
+    fn accept(&mut self) -> IoResult<Box<rtio::RtioPipe:Send>> {
+        self.native_accept().map(|s| box s as Box<rtio::RtioPipe:Send>)
     }
     fn set_timeout(&mut self, timeout: Option<u64>) {
         self.deadline = timeout.map(|a| ::io::timer::now() + a).unwrap_or(0);