From be26124797332e0763c7592854f2ff199cfb2819 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Mon, 26 Nov 2018 07:49:35 +0100
Subject: [PATCH] Be clear about Inner::kind being deliberate UB (#236)

---
 src/bytes.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/bytes.rs b/src/bytes.rs
index 3d6fb31..d7071d7 100644
--- a/src/bytes.rs
+++ b/src/bytes.rs
@@ -2429,6 +2429,10 @@ impl Inner {
         // bits, so even without any explicit atomic operations, reading the
         // flag will be correct.
         //
+        // This is undefind behavior due to a data race, but experimental
+        // evidence shows that it works in practice (discussion:
+        // https://internals.rust-lang.org/t/bit-wise-reasoning-for-atomic-accesses/8853).
+        //
         // This function is very critical performance wise as it is called for
         // every operation. Performing an atomic load would mess with the
         // compiler's ability to optimize. Simple benchmarks show up to a 10%