regcomp.c - remove (**{ ... }) from the regex engine

Dave M pointed out that this idea was flawed, and after some testing I have
come to agree with him. This removes it. It was only available for 5.37.8,
so no deprecation cycle involved.

The point of (**{ ... }) was to have a postponed eval that does not disable
optimizations. But some of the optimizations are disabled because if they
are not we do not match correctly as the optimizations will make unwarranted
assumptions about the pattern, assumptions which can be incorrect depending
on what pattern is returned from the codeblock. The original idea was
proposed because (?{ ... }) was treated as though it was (??{ ... }) and
disabled many optimizations, when in fact it doesn't interact with
optimizations at all. When I added (*{ ... }) as the optimistic version of
(?{ ... }) I used "completeness" as the justification for also adding
(**{ ... }) when it does not make sense to do so.

1 files changed, 6 insertions, 6 deletions

diff --git a/pod/perldelta.pod b/pod/perldelta.pod
index 788ada2996..7a81735089 100644
--- a/pod/perldelta.pod
+++ b/pod/perldelta.pod
@@ -37,13 +37,13 @@ L</Selected Bug Fixes> section.
 
 =head1 Incompatible Changes
 
-XXX For a release on a stable branch, this section aspires to be:
+=head2 (**{ ... }) removed from the regex engine.
 
-    There are no changes intentionally incompatible with 5.XXX.XXX
-    If any exist, they are bugs, and we request that you submit a
-    report.  See L</Reporting Bugs> below.
-
-[ List each incompatible change as a =head2 entry ]
+This feature was released as part of 5.37.8, after some use and
+discussion it was seen as more problematic than understood at first
+and has been removed in 5.37.9. It was only ever present in a single
+dev release and has never been released as part of a production perl,
+thus no deprecation cycle has been performed.
 
 =head1 Deprecations