Remove moves from *T and implement in another way

Author: nikomatsakis

src/libextra/c_vec.rs

@@ -122,7 +122,7 @@ pub unsafe fn c_vec_with_dtor<T>(base: *mut T, len: uint, dtor: @fn())
  */
 pub fn get<T:Copy>(t: CVec<T>, ofs: uint) -> T {
     assert!(ofs < len(t));
-    return unsafe { *ptr::mut_offset(t.base, ofs) };
+    return unsafe { copy *ptr::mut_offset(t.base, ofs) };
 }
 
 /**

src/libstd/pipes.rs

@@ -85,7 +85,8 @@ bounded and unbounded protocols allows for less code duplication.
 #[allow(missing_doc)];
 
 use container::Container;
-use cast::{forget, transmute, transmute_copy};
+use cast::{forget, transmute, transmute_copy, transmute_mut};
+use cast;
 use either::{Either, Left, Right};
 use iterator::IteratorUtil;
 use kinds::Owned;
@@ -102,10 +103,6 @@ use util::replace;
 
 static SPIN_COUNT: uint = 0;
 
-macro_rules! move_it (
-    { $x:expr } => ( unsafe { let y = *ptr::to_unsafe_ptr(&($x)); y } )
-)
-
 #[deriving(Eq)]
 enum State {
     Empty,
@@ -316,9 +313,11 @@ impl<T> Drop for BufferResource<T> {
     fn finalize(&self) {
         unsafe {
             // FIXME(#4330) Need self by value to get mutability.
-            let this: &mut BufferResource<T> = transmute(self);
+            let this: &mut BufferResource<T> = transmute_mut(self);
+
+            let null_buffer: ~Buffer<T> = transmute(ptr::null::<Buffer<T>>());
+            let mut b = replace(&mut this.buffer, null_buffer);
 
-            let mut b = move_it!(this.buffer);
             //let p = ptr::to_unsafe_ptr(*b);
             //error!("drop %?", p);
             let old_count = intrinsics::atomic_xsub_rel(

src/libstd/task/spawn.rs

@@ -98,10 +98,6 @@ use iterator::{IteratorUtil};
 #[cfg(test)] use comm;
 #[cfg(test)] use task;
 
-macro_rules! move_it (
-    { $x:expr } => ( unsafe { let y = *ptr::to_unsafe_ptr(&($x)); y } )
-)
-
 type TaskSet = HashSet<*rust_task>;
 
 fn new_taskset() -> TaskSet {
@@ -638,23 +634,16 @@ fn spawn_raw_oldsched(mut opts: TaskOpts, f: ~fn()) {
                           notify_chan: Option<Chan<TaskResult>>,
                           f: ~fn())
                        -> ~fn() {
-        let child_data = Cell::new((child_arc, ancestors));
+        let child_data = Cell::new((notify_chan, child_arc, ancestors));
         let result: ~fn() = || {
             // Agh. Get move-mode items into the closure. FIXME (#2829)
-            let mut (child_arc, ancestors) = child_data.take();
+            let mut (notify_chan, child_arc, ancestors) = child_data.take();
             // Child task runs this code.
 
             // Even if the below code fails to kick the child off, we must
             // send Something on the notify channel.
 
-            //let mut notifier = None;//notify_chan.map(|c| AutoNotify(c));
-            let notifier = match notify_chan {
-                Some(ref notify_chan_value) => {
-                    let moved_ncv = move_it!(*notify_chan_value);
-                    Some(AutoNotify(moved_ncv))
-                }
-                _ => None
-            };
+            let notifier = notify_chan.map_consume(|c| AutoNotify(c));
 
             if enlist_many(child, &child_arc, &mut ancestors) {
                 let group = @@mut TCB(child,

src/test/run-pass/pipe-bank-proto.rs

@@ -45,24 +45,18 @@ proto! bank (
     }
 )
 
-macro_rules! move_it (
-    { $x:expr } => { unsafe { let y = *ptr::to_unsafe_ptr(&($x)); y } }
-)
-
 fn switch<T:Owned,U>(endp: pipes::RecvPacket<T>,
                      f: &fn(v: Option<T>) -> U) -> U {
     f(pipes::try_recv(endp))
 }
 
-fn move_it<T>(x: T) -> T { x }
-
 macro_rules! follow (
     {
         $($message:path$(($($x: ident),+))||* -> $next:ident $e:expr)+
     } => (
         |m| match m {
           $(Some($message($($($x,)+)* next)) => {
-            let $next = move_it!(next);
+            let $next = next;
             $e })+
           _ => { fail!() }
         }
@@ -96,7 +90,7 @@ fn bank_client(bank: bank::client::login) {
     let bank = client::login(bank, ~"theincredibleholk", ~"1234");
     let bank = match try_recv(bank) {
       Some(ok(connected)) => {
-        move_it!(connected)
+        connected
       }
       Some(invalid(_)) => { fail!("login unsuccessful") }
       None => { fail!("bank closed the connection") }