From bddd34c507d5733ccd92c0f6dd8a6e6920fe42cd Mon Sep 17 00:00:00 2001
From: Richard Leach <richardleach@users.noreply.github.com>
Date: Tue, 5 Nov 2024 00:35:44 +0000
Subject: [PATCH] perl5411delta.pod - add detail about IsCOW constant-folded
 strings

---
 pod/perl5411delta.pod | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/pod/perl5411delta.pod b/pod/perl5411delta.pod
index 73579737f6..4fd156c15b 100644
--- a/pod/perl5411delta.pod
+++ b/pod/perl5411delta.pod
@@ -28,7 +28,21 @@ directly>. These cases are now fully supported.
 
 =item *
 
-Various optimizations related to handling of C<CONST>s.
+Constant-folded strings are now sharable via the Copy-on-Write mechanism.
+[L<GH #22163|https://github.com/Perl/perl5/pull/22163>]
+
+The following code would previously have allocated eleven string buffers,
+each containing one million "A"s:
+
+C<my @scalars; push @scalars, ("A" x 1_000_000) for 0..9;>
+
+Now a single buffer is allocated and shared between a CONST OP and
+the ten scalar elements of L<@scalars>.
+
+Note that any code using this sort of constant to simulate memory leaks
+(perhaps in test files) must now permute the string in order to trigger
+a string copy and the allocation of separate buffers. For example,
+C<("A" x 1_000_000).time> might be a suitable small change.
 
 =item *