From f94d671bfae5d8e9a4a4add310b1c40af0ab62a6 Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Fri, 9 May 2014 10:34:51 -0700
Subject: core: Remove the cast module

This commit revisits the `cast` module in libcore and libstd, and scrutinizes
all functions inside of it. The result was to remove the `cast` module entirely,
folding all functionality into the `mem` module. Specifically, this is the fate
of each function in the `cast` module.

* transmute - This function was moved to `mem`, but it is now marked as
              #[unstable]. This is due to planned changes to the `transmute`
              function and how it can be invoked (see the #[unstable] comment).
              For more information, see RFC 5 and #12898

* transmute_copy - This function was moved to `mem`, with clarification that is
                   is not an error to invoke it with T/U that are different
                   sizes, but rather that it is strongly discouraged. This
                   function is now #[stable]

* forget - This function was moved to `mem` and marked #[stable]

* bump_box_refcount - This function was removed due to the deprecation of
                      managed boxes as well as its questionable utility.

* transmute_mut - This function was previously deprecated, and removed as part
                  of this commit.

* transmute_mut_unsafe - This function doesn't serve much of a purpose when it
                         can be achieved with an `as` in safe code, so it was
                         removed.

* transmute_lifetime - This function was removed because it is likely a strong
                       indication that code is incorrect in the first place.

* transmute_mut_lifetime - This function was removed for the same reasons as
                           `transmute_lifetime`

* copy_lifetime - This function was moved to `mem`, but it is marked
                  `#[unstable]` now due to the likelihood of being removed in
                  the future if it is found to not be very useful.

* copy_mut_lifetime - This function was also moved to `mem`, but had the same
                      treatment as `copy_lifetime`.

* copy_lifetime_vec - This function was removed because it is not used today,
                      and its existence is not necessary with DST
                      (copy_lifetime will suffice).

In summary, the cast module was stripped down to these functions, and then the
functions were moved to the `mem` module.

    transmute - #[unstable]
    transmute_copy - #[stable]
    forget - #[stable]
    copy_lifetime - #[unstable]
    copy_mut_lifetime - #[unstable]

[breaking-change]
---
 src/libstd/sync/spsc_queue.rs | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

(limited to 'src/libstd/sync/spsc_queue.rs')

diff --git a/src/libstd/sync/spsc_queue.rs b/src/libstd/sync/spsc_queue.rs
index 7854a0e168e..ed6d690def0 100644
--- a/src/libstd/sync/spsc_queue.rs
+++ b/src/libstd/sync/spsc_queue.rs
@@ -33,8 +33,8 @@
 //! concurrently between two tasks. This data structure is safe to use and
 //! enforces the semantics that there is one pusher and one popper.
 
-use cast;
 use kinds::Send;
+use mem;
 use ops::Drop;
 use option::{Some, None, Option};
 use owned::Box;
@@ -74,7 +74,7 @@ pub struct Queue<T> {
 impl<T: Send> Node<T> {
     fn new() -> *mut Node<T> {
         unsafe {
-            cast::transmute(box Node {
+            mem::transmute(box Node {
                 value: None,
                 next: AtomicPtr::new(0 as *mut Node<T>),
             })
@@ -188,7 +188,7 @@ impl<T: Send> Queue<T> {
                     (*self.tail_prev.load(Relaxed)).next.store(next, Relaxed);
                     // We have successfully erased all references to 'tail', so
                     // now we can safely drop it.
-                    let _: Box<Node<T>> = cast::transmute(tail);
+                    let _: Box<Node<T>> = mem::transmute(tail);
                 }
             }
             return ret;
@@ -216,7 +216,7 @@ impl<T: Send> Drop for Queue<T> {
             let mut cur = self.first;
             while !cur.is_null() {
                 let next = (*cur).next.load(Relaxed);
-                let _n: Box<Node<T>> = cast::transmute(cur);
+                let _n: Box<Node<T>> = mem::transmute(cur);
                 cur = next;
             }
         }
-- 
cgit 1.4.1-3-g733a5