libsyntax: Forbid ~mut and ~const. rs=demuting

Author: pcwalton

doc/tutorial.md

@@ -1126,7 +1126,7 @@ points to.
 
 ~~~
 let managed = @mut 10;
-let owned = ~mut 20;
+let mut owned = ~20;
 
 let mut value = 30;
 let borrowed = &mut value;

src/libcore/owned.rs

@@ -13,22 +13,22 @@
 use cmp::{Eq, Ord};
 
 #[cfg(notest)]
-impl<T:Eq> Eq for ~const T {
+impl<T:Eq> Eq for ~T {
     #[inline(always)]
-    pure fn eq(&self, other: &~const T) -> bool { *(*self) == *(*other) }
+    pure fn eq(&self, other: &~T) -> bool { *(*self) == *(*other) }
     #[inline(always)]
-    pure fn ne(&self, other: &~const T) -> bool { *(*self) != *(*other) }
+    pure fn ne(&self, other: &~T) -> bool { *(*self) != *(*other) }
 }
 
 #[cfg(notest)]
-impl<T:Ord> Ord for ~const T {
+impl<T:Ord> Ord for ~T {
     #[inline(always)]
-    pure fn lt(&self, other: &~const T) -> bool { *(*self) < *(*other) }
+    pure fn lt(&self, other: &~T) -> bool { *(*self) < *(*other) }
     #[inline(always)]
-    pure fn le(&self, other: &~const T) -> bool { *(*self) <= *(*other) }
+    pure fn le(&self, other: &~T) -> bool { *(*self) <= *(*other) }
     #[inline(always)]
-    pure fn ge(&self, other: &~const T) -> bool { *(*self) >= *(*other) }
+    pure fn ge(&self, other: &~T) -> bool { *(*self) >= *(*other) }
     #[inline(always)]
-    pure fn gt(&self, other: &~const T) -> bool { *(*self) > *(*other) }
+    pure fn gt(&self, other: &~T) -> bool { *(*self) > *(*other) }
 }
 

src/libstd/arc.rs

@@ -17,6 +17,7 @@ use sync;
 use sync::{Mutex, mutex_with_condvars, RWlock, rwlock_with_condvars};
 
 use core::cast;
+use core::cell::Cell;
 use core::pipes;
 use core::prelude::*;
 use core::private::{SharedMutableState, shared_mutable_state};
@@ -532,17 +533,17 @@ mod tests {
         let arc = ~MutexARC(false);
         let arc2 = ~arc.clone();
         let (p,c) = comm::oneshot();
-        let (c,p) = (~mut Some(c), ~mut Some(p));
+        let (c,p) = (Cell(c), Cell(p));
         do task::spawn || {
             // wait until parent gets in
-            comm::recv_one(option::swap_unwrap(p));
+            comm::recv_one(p.take());
             do arc2.access_cond |state, cond| {
                 *state = true;
                 cond.signal();
             }
         }
         do arc.access_cond |state, cond| {
-            comm::send_one(option::swap_unwrap(c), ());
+            comm::send_one(c.take(), ());
             assert !*state;
             while !*state {
                 cond.wait();

src/libstd/future.rs

@@ -23,6 +23,7 @@
 
 use core::cast::copy_lifetime;
 use core::cast;
+use core::cell::Cell;
 use core::either::Either;
 use core::option;
 use core::comm::{oneshot, ChanOne, PortOne, send_one, recv_one};
@@ -103,11 +104,9 @@ pub fn from_port<A:Owned>(port: PortOne<A>) ->
      * waiting for the result to be received on the port.
      */
 
-    let port = ~mut Some(port);
+    let port = Cell(port);
     do from_fn || {
-        let mut port_ = None;
-        port_ <-> *port;
-        let port = option::unwrap(port_);
+        let port = port.take();
         match recv(port) {
             oneshot::send(data) => data
         }
@@ -136,9 +135,9 @@ pub fn spawn<A:Owned>(blk: fn~() -> A) -> Future<A> {
 
     let (chan, port) = oneshot::init();
 
-    let chan = ~mut Some(chan);
+    let chan = Cell(chan);
     do task::spawn || {
-        let chan = option::swap_unwrap(&mut *chan);
+        let chan = chan.take();
         send_one(chan, blk());
     }
 

src/libstd/sync.rs

@@ -15,6 +15,7 @@
  * in std.
  */
 
+use core::cell::Cell;
 use core::option;
 use core::pipes;
 use core::prelude::*;
@@ -799,9 +800,9 @@ mod tests {
             let s = ~semaphore(1);
             let s2 = ~s.clone();
             let (p,c) = comm::stream();
-            let child_data = ~mut Some((s2, c));
+            let child_data = Cell((s2, c));
             do s.access {
-                let (s2,c) = option::swap_unwrap(child_data);
+                let (s2, c) = child_data.take();
                 do task::spawn || {
                     c.send(());
                     do s2.access { }
@@ -976,13 +977,13 @@ mod tests {
             let mut sibling_convos = ~[];
             for 2.times {
                 let (p,c) = comm::stream();
-                let c = ~mut Some(c);
+                let c = Cell(c);
                 sibling_convos.push(p);
                 let mi = ~m2.clone();
                 // spawn sibling task
-                do task::spawn || { // linked
+                do task::spawn { // linked
                     do mi.lock_cond |cond| {
-                        let c = option::swap_unwrap(c);
+                        let c = c.take();
                         c.send(()); // tell sibling to go ahead
                         let _z = SendOnFailure(c);
                         cond.wait(); // block forever

src/libstd/workcache.rs

@@ -15,6 +15,7 @@ use sha1;
 use serialize::{Encoder, Encodable, Decoder, Decodable};
 use sort;
 
+use core::cell::Cell;
 use core::cmp;
 use core::either::{Either, Left, Right};
 use core::io;
@@ -339,11 +340,11 @@ impl TPrep for @Mut<Prep> {
                     let mut blk = None;
                     blk <-> bo;
                     let blk = blk.unwrap();
-                    let chan = ~mut Some(chan);
+                    let chan = Cell(chan);
                     do task::spawn || {
                         let exe = Exec{discovered_inputs: LinearMap::new(),
                                        discovered_outputs: LinearMap::new()};
-                        let chan = option::swap_unwrap(&mut *chan);
+                        let chan = chan.take();
                         let v = blk(&exe);
                         send_one(chan, (exe, v));
                     }

src/libsyntax/parse/obsolete.rs

@@ -128,7 +128,7 @@ pub impl Parser {
                 "write `+` between trait bounds"
             ),
             ObsoleteMutOwnedPointer => (
-                "mutable owned pointer",
+                "const or mutable owned pointer",
                 "mutability inherits through `~` pointers; place the `~` box
                  in a mutable location, like a mutable local variable or an \
                  `@mut` box"

src/libsyntax/parse/parser.rs

@@ -678,7 +678,7 @@ pub impl Parser {
         // reflected in the AST type.
         let mt = self.parse_mt();
 
-        if mt.mutbl == m_mutbl && sigil == OwnedSigil {
+        if mt.mutbl != m_imm && sigil == OwnedSigil {
             self.obsolete(*self.last_span, ObsoleteMutOwnedPointer);
         }
 
@@ -1574,6 +1574,10 @@ pub impl Parser {
           token::TILDE => {
             self.bump();
             let m = self.parse_mutability();
+            if m != m_imm {
+                self.obsolete(*self.last_span, ObsoleteMutOwnedPointer);
+            }
+
             let e = self.parse_prefix_expr();
             hi = e.span.hi;
             // HACK: turn ~[...] into a ~-evec