From 406cbf1a39c99ef7b7f329a44f1d1c7af7a8ecda Mon Sep 17 00:00:00 2001
From: Donato Sciarra <sciarp@gmail.com>
Date: Fri, 12 Oct 2018 00:34:26 +0200
Subject: Support underscore as constant name

Issue: 54912
---
 src/libsyntax/parse/parser.rs | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

(limited to 'src/libsyntax/parse/parser.rs')

diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index b5896f37c00..c7089a295fc 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -6346,7 +6346,13 @@ impl<'a> Parser<'a> {
     }
 
     fn parse_item_const(&mut self, m: Option<Mutability>) -> PResult<'a, ItemInfo> {
-        let id = self.parse_ident()?;
+        let id = match self.token {
+                token::Ident(ident, false) if ident.name == keywords::Underscore.name() => {
+                    self.bump(); // `_`
+                    ident.gensym()
+                    },
+                _ => self.parse_ident()?,
+            };
         self.expect(&token::Colon)?;
         let ty = self.parse_ty()?;
         self.expect(&token::Eq)?;
-- 
cgit 1.4.1-3-g733a5