From 43da87939dd508350a93676fe2240d9b334a8d76 Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Wed, 8 Mar 2023 18:38:09 -0800
Subject: [PATCH] Simplify parsing of borrow="..." attributes

---
 serde_derive/src/internals/attr.rs | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/serde_derive/src/internals/attr.rs b/serde_derive/src/internals/attr.rs
index 473458de..9b2162da 100644
--- a/serde_derive/src/internals/attr.rs
+++ b/serde_derive/src/internals/attr.rs
@@ -5,7 +5,7 @@ use quote::ToTokens;
 use std::borrow::Cow;
 use std::collections::BTreeSet;
 use syn;
-use syn::parse::{Parse, ParseStream};
+use syn::parse::ParseStream;
 use syn::punctuated::Punctuated;
 use syn::Ident;
 use syn::Meta::{List, NameValue, Path};
@@ -1662,15 +1662,9 @@ fn parse_lit_into_lifetimes(
         return Err(());
     }
 
-    struct BorrowedLifetimes(Punctuated<syn::Lifetime, Token![+]>);
-
-    impl Parse for BorrowedLifetimes {
-        fn parse(input: ParseStream) -> syn::Result<Self> {
-            Punctuated::parse_separated_nonempty(input).map(BorrowedLifetimes)
-        }
-    }
-
-    if let Ok(BorrowedLifetimes(lifetimes)) = string.parse() {
+    if let Ok(lifetimes) =
+        string.parse_with(Punctuated::<syn::Lifetime, Token![+]>::parse_separated_nonempty)
+    {
         let mut set = BTreeSet::new();
         for lifetime in lifetimes {
             if !set.insert(lifetime.clone()) {