From 16c4bb476c4a34cf6680568edf5dd65b3965d340 Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Thu, 5 May 2022 21:34:28 -0700
Subject: [PATCH 1/2] Eliminate an allocation from Literal::byte_string

    error: `format!(..)` appended to existing `String`
       --> src/fallback.rs:879:22
        |
    879 |                 _ => escaped.push_str(&format!("\\x{:02X}", b)),
        |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        |
        = note: `-D clippy::format-push-string` implied by `-D clippy::all`
        = help: consider using `write!` to avoid the extra allocation
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#format_push_string
---
 src/fallback.rs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/fallback.rs b/src/fallback.rs
index be53877f..c365ecbf 100644
--- a/src/fallback.rs
+++ b/src/fallback.rs
@@ -4,7 +4,7 @@ use crate::{Delimiter, Spacing, TokenTree};
 use std::cell::RefCell;
 #[cfg(span_locations)]
 use std::cmp;
-use std::fmt::{self, Debug, Display};
+use std::fmt::{self, Debug, Display, Write as _};
 use std::iter::FromIterator;
 use std::mem;
 use std::ops::RangeBounds;
@@ -876,7 +876,9 @@ impl Literal {
                 b'"' => escaped.push_str("\\\""),
                 b'\\' => escaped.push_str("\\\\"),
                 b'\x20'..=b'\x7E' => escaped.push(*b as char),
-                _ => escaped.push_str(&format!("\\x{:02X}", b)),
+                _ => {
+                    let _ = write!(escaped, "\\x{:02X}", b);
+                }
             }
         }
         escaped.push('"');

From d307f5650aa0dbc77c5a277300ad12550fef60cc Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Thu, 5 May 2022 21:39:18 -0700
Subject: [PATCH 2/2] Restore support for rust pre-1.33

    error[E0658]: renaming imports with `_` is unstable (see issue 48216)
     --> src/fallback.rs:7:38
      |
    7 | use std::fmt::{self, Debug, Display, Write as _};
      |                                      ^^^^^^^^^^
---
 src/fallback.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/fallback.rs b/src/fallback.rs
index c365ecbf..21ede03f 100644
--- a/src/fallback.rs
+++ b/src/fallback.rs
@@ -4,7 +4,7 @@ use crate::{Delimiter, Spacing, TokenTree};
 use std::cell::RefCell;
 #[cfg(span_locations)]
 use std::cmp;
-use std::fmt::{self, Debug, Display, Write as _};
+use std::fmt::{self, Debug, Display, Write};
 use std::iter::FromIterator;
 use std::mem;
 use std::ops::RangeBounds;