Put a space before colon that appears after a meta variable

Closes #2534.

1 files changed, 4 insertions, 0 deletions

diff --git a/src/macros.rs b/src/macros.rs
index e36b4c51993..784e6c5798b 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -522,6 +522,7 @@ impl MacroArgKind {
             _ => false,
         }
     }
+
     fn starts_with_dollar(&self) -> bool {
         match *self {
             MacroArgKind::Repeat(..) | MacroArgKind::MetaVariable(..) => true,
@@ -777,6 +778,9 @@ impl MacroArgParser {
             if ident_like(&self.start_tok) {
                 return true;
             }
+            if self.start_tok == Token::Colon {
+                return true;
+            }
         }
 
         if force_space_before(&self.start_tok) {