From fb7964fde70c603d91005aa18f87905e5df894c0 Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Thu, 13 Apr 2017 16:36:24 -0700
Subject: [PATCH] Clean up serialize_display_bounded_length

---
 serde/src/ser/impls.rs | 46 ++++++++++++++++++------------------------
 1 file changed, 20 insertions(+), 26 deletions(-)

diff --git a/serde/src/ser/impls.rs b/serde/src/ser/impls.rs
index 0fb48c11..291c6670 100644
--- a/serde/src/ser/impls.rs
+++ b/serde/src/ser/impls.rs
@@ -369,34 +369,30 @@ impl Serialize for Duration {
 
 ////////////////////////////////////////////////////////////////////////////////
 
-/// Seralize the `$value` that implements Display as a string,
-/// when that string is statically known to never have more than
-/// a constant `$MAX_LEN` bytes.
+/// Serialize a value that implements `Display` as a string, when that string is
+/// statically known to never have more than a constant `MAX_LEN` bytes.
 ///
-/// Panics if the Display impl tries to write more than `$MAX_LEN` bytes.
+/// Panics if the `Display` impl tries to write more than `MAX_LEN` bytes.
 #[cfg(feature = "std")]
 macro_rules! serialize_display_bounded_length {
-    ($value: expr, $MAX_LEN: expr, $serializer: expr) => {
-        {
-            let mut buffer: [u8; $MAX_LEN] = unsafe { mem::uninitialized() };
-            let remaining_len;
-            {
-                let mut remaining = &mut buffer[..];
-                write!(remaining, "{}", $value).unwrap();
-                remaining_len = remaining.len()
-            }
-            let written_len = buffer.len() - remaining_len;
-            let written = &buffer[..written_len];
+    ($value:expr, $max:expr, $serializer:expr) => {{
+        let mut buffer: [u8; $max] = unsafe { mem::uninitialized() };
+        let remaining_len = {
+            let mut remaining = &mut buffer[..];
+            write!(remaining, "{}", $value).unwrap();
+            remaining.len()
+        };
+        let written_len = buffer.len() - remaining_len;
+        let written = &buffer[..written_len];
 
-            // write! only provides fmt::Formatter to Display implementations,
-            // which has methods write_str and write_char but no method to write arbitrary bytes.
-            // Therefore, `written` is well-formed in UTF-8.
-            let written_str = unsafe {
-                str::from_utf8_unchecked(written)
-            };
-            $serializer.serialize_str(written_str)
-        }
-    }
+        // write! only provides fmt::Formatter to Display implementations, which
+        // has methods write_str and write_char but no method to write arbitrary
+        // bytes. Therefore `written` must be valid UTF-8.
+        let written_str = unsafe {
+            str::from_utf8_unchecked(written)
+        };
+        $serializer.serialize_str(written_str)
+    }}
 }
 
 #[cfg(feature = "std")]
@@ -436,8 +432,6 @@ impl Serialize for net::Ipv6Addr {
     }
 }
 
-////////////////////////////////////////////////////////////////////////////////
-
 #[cfg(feature = "std")]
 impl Serialize for net::SocketAddr {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>