From 9c11827d7cc94a110a41b26ad78e0c9aad030b5b Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Mon, 25 Jan 2021 19:26:53 +0000
Subject: [PATCH] utils: Improve display_as_debug! so it can pass generic
 params

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 src/error.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/error.rs b/src/error.rs
index 676acb65..22d9f97e 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -181,8 +181,8 @@ impl IdForById for PieceId {
 
 #[macro_export]
 macro_rules! display_as_debug {
-  {$x:ty} => {
-    impl std::fmt::Display for $x {
+  {$x:ty $( , $($gen_tt:tt)* )?} => {
+    impl $( $($gen_tt)* )? std::fmt::Display for $x {
       #[throws(std::fmt::Error)]
       fn fmt(&self, f: &mut std::fmt::Formatter) {
         <Self as Debug>::fmt(self, f)?
-- 
2.30.2