From f301e09e02334c936a9fb95c4bc485a359506aa2 Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Thu, 9 Mar 2023 00:20:51 -0800
Subject: [PATCH] Simplify parsing of where-predicates in bound attribute

---
 serde_derive/src/internals/attr.rs | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/serde_derive/src/internals/attr.rs b/serde_derive/src/internals/attr.rs
index 9fd3ef25..6bd50e90 100644
--- a/serde_derive/src/internals/attr.rs
+++ b/serde_derive/src/internals/attr.rs
@@ -1627,11 +1627,9 @@ fn parse_lit_into_where(
 ) -> Result<Vec<syn::WherePredicate>, ()> {
     let string = get_lit_str2(cx, attr_name, meta_item_name, lit)?;
 
-    let where_string = syn::LitStr::new(&format!("where {}", string.value()), string.span());
-
-    where_string
-        .parse::<syn::WhereClause>()
-        .map(|wh| wh.predicates.into_iter().collect())
+    string
+        .parse_with(Punctuated::<syn::WherePredicate, Token![,]>::parse_terminated)
+        .map(|predicates| predicates.into_iter().collect())
         .map_err(|err| cx.error_spanned_by(lit, err))
 }