`once` is not keyword now
@@ -194,11 +194,11 @@ grammar as double-quoted strings. Other tokens have exact rules given.
| else | enum | extern | false | final |
| fn | for | if | impl | in |
| let | loop | match | mod | move |
-| mut | offsetof | once | override | priv |
-| pub | pure | ref | return | sizeof |
-| static | self | struct | super | true |
-| trait | type | typeof | unsafe | unsized |
-| use | virtual | where | while | yield |
+| mut | offsetof | override | priv | pub |
+| pure | ref | return | sizeof | static |
+| self | struct | super | true | trait |
+| type | typeof | unsafe | unsized | use |
+| virtual | where | while | yield |
Each of these keywords has special meaning in its grammar, and all of them are
