auto merge of #12445 : huonw/rust/less-unsafe, r=alexcrichton

Commits for details. Highlights:

- `flate` returns `CVec<u8>` to save reallocating a whole new `&[u8]`
- a lot of `transmute`s removed outright or replaced with `as` (etc.)

1 files changed, 1 insertions, 3 deletions

diff --git a/src/libserialize/ebml.rs b/src/libserialize/ebml.rs
index b7e1e5a8da7..bc9eee51753 100644
--- a/src/libserialize/ebml.rs
+++ b/src/libserialize/ebml.rs
@@ -161,9 +161,7 @@ pub mod reader {
         ];
 
         unsafe {
-            let (ptr, _): (*u8, uint) = transmute(data);
-            let ptr = ptr.offset(start as int);
-            let ptr: *i32 = transmute(ptr);
+            let ptr = data.as_ptr().offset(start as int) as *i32;
             let val = from_be32(*ptr) as u32;
 
             let i = (val >> 28u) as uint;