---

yaml
---
r: 147699
b: refs/heads/try2
c: 4b4ff2c
h: refs/heads/master
i:
  147697: 7bff1cb
  147695: 0c79be4
v: v3

Author: pcwalton

[refs]

@@ -5,7 +5,7 @@ refs/heads/snap-stage3: 78a7676898d9f80ab540c6df5d4c9ce35bb50463
 refs/heads/try: 519addf6277dbafccbb4159db4b710c37eaa2ec5
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
-refs/heads/try2: fc0b466fd47ebe7f40a08276cbb26ef1f5657fce
+refs/heads/try2: 4b4ff2cf8b5f888581d41b3b2f10dacf7d716478
 refs/heads/dist-snap: ba4081a5a8573875fed17545846f6f6902c8ba8d
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503

branches/try2/src/librustc/middle/trans/_match.rs

@@ -219,6 +219,7 @@ use middle::ty;
 use util::common::indenter;
 use util::ppaux::{Repr, vec_map_to_str};
 
+use std::cell::Cell;
 use std::hashmap::HashMap;
 use std::ptr;
 use std::vec;
@@ -1188,19 +1189,19 @@ struct DynamicFailureHandler {
     bcx: @Block,
     sp: Span,
     msg: @str,
-    finished: @mut Option<BasicBlockRef>,
+    finished: @Cell<Option<BasicBlockRef>>,
 }
 
 impl CustomFailureHandler for DynamicFailureHandler {
     fn handle_fail(&self) -> BasicBlockRef {
-        match *self.finished {
+        match self.finished.get() {
             Some(bb) => return bb,
             _ => (),
         }
 
         let fail_cx = sub_block(self.bcx, "case_fallthrough");
         controlflow::trans_fail(fail_cx, Some(self.sp), self.msg);
-        *self.finished = Some(fail_cx.llbb);
+        self.finished.set(Some(fail_cx.llbb));
         fail_cx.llbb
     }
 }
@@ -1911,7 +1912,7 @@ fn trans_match_inner(scope_cx: @Block,
     let chk = {
         if ty::type_is_empty(tcx, t) {
             // Special case for empty types
-            let fail_cx = @mut None;
+            let fail_cx = @Cell::new(None);
             let fail_handler = @DynamicFailureHandler {
                 bcx: scope_cx,
                 sp: discr_expr.span,