Merge pull request rust-lang#671 from pearzl/master

missing a parenthesis

src/macros-by-example.md

@@ -177,7 +177,7 @@ compiler knows how to expand them properly:
     number of fragments. For instance, `( $( $i:ident ),* ; $( $j:ident ),* ) =>
     ( $( ($i,$j) ),*` must bind the same number of `$i` fragments as `$j`
     fragments. This means that invoking the macro with `(a, b, c; d, e, f`) is
-    legal and expands to `((a,d), (b,e), c,f))`, but `(a, b, c; d, e)` is
+    legal and expands to `((a,d), (b,e), (c,f))`, but `(a, b, c; d, e)` is
     illegal because it does not have the same number. This requirement applies
     to every layer of nested repetitions.