From 4e5dc6d9686a34d446147b923fe838389758a512 Mon Sep 17 00:00:00 2001
From: Jonathan Wakely <jwakely@redhat.com>
Date: Sun, 4 Feb 2024 21:39:11 +0000
Subject: [PATCH] libstdc++: Add comment to gslice::operator=(const gslice&)
[PR100147]
There's no need to check for self-assignment here, it would just add
extra code for an unlikely case. Add a comment saying so.
libstdc++-v3/ChangeLog:
PR libstdc++/100147
* include/bits/gslice.h (operator=): Add comment about lack of
self-assignment check.
---
libstdc++-v3/include/bits/gslice.h | 2 ++
1 file changed, 2 insertions(+)
diff --git a/libstdc++-v3/include/bits/gslice.h b/libstdc++-v3/include/bits/gslice.h
index 3d78da2bd754..d9a8b929a571 100644
--- a/libstdc++-v3/include/bits/gslice.h
+++ b/libstdc++-v3/include/bits/gslice.h
@@ -169,6 +169,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
inline gslice&
gslice::operator=(const gslice& __g)
{
+ // Safe for self-assignment. Checking for it would add overhead just to
+ // optimize a case that should never happen anyway.
if (__g._M_index)
__g._M_index->_M_increment_use();
if (_M_index && _M_index->_M_decrement_use() == 0)
--
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