Stripping trailing commas and spaces from `vec!` elements (#1219)

* Stripping trailing commas and spaces from `vec!` elements

* Stripping trailing commas and spaces ONLY from `vec!` elements

* Added comment

1 files changed, 6 insertions, 1 deletions

diff --git a/src/macros.rs b/src/macros.rs
index dd301ad9de7..250fd81099c 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -114,7 +114,12 @@ pub fn rewrite_macro(mac: &ast::Mac,
             parser.bump();
 
             if parser.token == Token::Eof {
-                return None;
+                // vec! is a special case of bracket macro which should be formated as an array.
+                if macro_name == "vec!" {
+                    break;
+                } else {
+                    return None;
+                }
             }
         }
     }