librustc: Disallow "mut" from distributing over bindings.

This is the backwards-incompatible part of per-binding-site "mut".

1 files changed, 2 insertions, 1 deletions

diff --git a/src/libstd/rand/distributions.rs b/src/libstd/rand/distributions.rs
index 6f4f1a34977..e8dad2fc5e8 100644
--- a/src/libstd/rand/distributions.rs
+++ b/src/libstd/rand/distributions.rs
@@ -89,7 +89,8 @@ impl Rand for StandardNormal {
             // do-while, so the condition should be true on the first
             // run, they get overwritten anyway (0 < 1, so these are
             // good).
-            let mut (x, y) = (1.0, 0.0);
+            let mut x = 1.0;
+            let mut y = 0.0;
 
             // XXX infinities?
             while -2.0*y < x * x {