Perl named operators and builtin subs introduced since 5.6

Name	Availability	Experimental	In CORE::	Enabling pragma	Enabling feature set
`__CLASS__`	Since 5.40	—	Since 5.40	`use feature qw( class );`	—
`__SUB__`	Since 5.16	—	Since 5.16	`use feature qw( current_sub );`	5.16 and up
`ADJUST`	Since 5.38	Since 5.40	Since 5.38	`use feature qw( class );`	—
`all`	Since 5.42	Since 5.42	Since 5.42	`use feature qw( keyword_all );`	—
`any`	Since 5.42	Since 5.42	Since 5.42	`use feature qw( keyword_any );`	—
`blessed`	Since 5.36	From 5.36 until 5.40	—	`use builtin qw( blessed );`	5.40 and up
`break`	From 5.10	Since 5.16^[1] until 5.38 Deprecated from 5.38 until 5.42	Since 5.16	`use feature qw( switch );`	From 5.10 up to 5.36
`catch`	Since 5.34	From 5.34 until 5.40	Since 5.34	`use feature qw( try );`	5.40 and up
`ceil`	Since 5.36	From 5.36 until 5.40	—	`use builtin qw( ceil );`	5.40 and up
`class`	Since 5.38	Since 5.38	Since 5.38	`use feature qw( class );`	—
`continue`	From 5.10	Since 5.16^[1] until 5.38 Deprecated from 5.38 until 5.42	Since 5.16	`use feature qw( switch );`	From 5.10 up to 5.36
`created_as_number`	Since 5.36	Since 5.36	—	`use builtin qw( created_as_number );`	—
`created_as_string`	Since 5.36	Since 5.36	—	`use builtin qw( created_as_string );`	—
`default`	From 5.10	Since 5.16^[1] until 5.38 Deprecated from 5.38 until 5.42	Since 5.16	`use feature qw( switch );`	From 5.10 up to 5.36
`defer`	Since 5.36	Since 5.36	Since 5.36	`use feature qw( defer );`	5.40 and up
`export_lexically`	Since 5.38	Since 5.38	—	`use builtin qw( export_lexically );`	—
`false`	Since 5.36	From 5.36 until 5.40	—	`use builtin qw( false );`	—
`fc`	Since 5.16	—	Since 5.16	`use feature qw( fc );`	5.16 and up
`field`	Since 5.38	Since 5.38	Since 5.38	`use feature qw( class );`	—
`floor`	Since 5.36	From 5.36 until 5.40	—	`use builtin qw( floor );`	5.40 and up
`finally`	Since 5.36	Since 5.36	Since 5.36	`use feature qw( try );`	5.40 and up
`given`	From 5.10	Since 5.16^[1] until 5.38 Deprecated from 5.38 until 5.42	Since 5.16	`use feature qw( switch );`	From 5.10 up to 5.36
`indexed`	Since 5.36	From 5.36 until 5.40	—	`use builtin qw( indexed );`	5.40 and up
`inf`	Since 5.40	Since 5.40	—	`use builtin qw( inf );`	—
`is_bool`	Since 5.36	Since 5.36	—	`use builtin qw( is_bool );`	—
`is_tainted`	Since 5.38	From 5.38 until 5.40	—	`use builtin qw( is_tainted );`	5.40 and up
`is_weak`	Since 5.36	From 5.36 until 5.40	—	`use builtin qw( is_weak );`	5.40 and up
`isa`	Since 5.32	From 5.32 until 5.34	Since 5.32	`use feature qw( isa );`	5.36 and up
`load_module`	Since 5.40	Since 5.40	—	`use builtin qw( load_module );`	—
`method`	Since 5.38	Since 5.38	Since 5.38	`use feature qw( class );`	—
`nan`	Since 5.40	Since 5.40	—	`use builtin qw( nan );`	—
`refaddr`	Since 5.36	From 5.36 until 5.40	—	`use builtin qw( refaddr );`	5.40 and up
`reftype`	Since 5.36	From 5.36 until 5.40	—	`use builtin qw( reftype );`	5.40 and up
`say`	Since 5.10	—	Since 5.16	`use feature qw( say );`	5.10 and up
`state`	Since 5.10	—	Since 5.16	`use feature qw( state );`	5.10 and up
`stringify`	Since 5.40	Since 5.40	—	`use builtin qw( stringify );`	—
`trim`	Since 5.36	From 5.36 until 5.40	—	`use builtin qw( trim );`	5.40 and up
`true`	Since 5.36	From 5.36 until 5.40	—	`use builtin qw( true );`	5.40 and up
`try`	Since 5.34	From 5.34 until 5.40	Since 5.34	`use feature qw( try );`	5.40 and up
`unweaken`	Since 5.36	From 5.36 until 5.40	—	`use builtin qw( unweaken );`	5.40 and up
`weaken`	Since 5.36	From 5.36 until 5.40	—	`use builtin qw( weaken );`	5.40 and up
`when`	From 5.10	Since 5.16^[1] until 5.38 Deprecated from 5.38 until 5.42	Since 5.16	`use feature qw( switch );`	From 5.10 up to 5.36

`builtin::blessed`	Since 5.36	From 5.36 until 5.40	—	Always available
`builtin::ceil`	Since 5.36	From 5.36 until 5.40	—	Always available
`builtin::created_as_number`	Since 5.36	Since 5.36	—	Always available
`builtin::created_as_string`	Since 5.36	Since 5.36	—	Always available
`builtin::export_lexically`	Since 5.38	Since 5.38	—	Always available
`builtin::false`	Since 5.36	From 5.36 until 5.40	—	Always available
`builtin::floor`	Since 5.36	From 5.36 until 5.40	—	Always available
`builtin::indexed`	Since 5.36	From 5.36 until 5.40	—	Always available
`builtin::inf`	Since 5.40	Since 5.40	—	Always available
`builtin::is_bool`	Since 5.36	Since 5.36	—	Always available
`builtin::is_tainted`	Since 5.38	From 5.38 until 5.40	—	Always available
`builtin::is_weak`	Since 5.36	From 5.36 until 5.40	—	Always available
`builtin::load_module`	Since 5.40	Since 5.40	—	Always available
`builtin::nan`	Since 5.40	Since 5.40	—	Always available
`builtin::refaddr`	Since 5.36	From 5.36 until 5.40	—	Always available
`builtin::reftype`	Since 5.36	From 5.36 until 5.40	—	Always available
`builtin::stringify`	Since 5.40	Since 5.40	—	Always available
`builtin::trim`	Since 5.36	From 5.36 until 5.40	—	Always available
`builtin::true`	Since 5.36	From 5.36 until 5.40	—	Always available
`builtin::unweaken`	Since 5.36	From 5.36 until 5.40	—	Always available
`builtin::weaken`	Since 5.36	From 5.36 until 5.40	—	Always available

`utf8::decode`	Since 5.8	—	—	Always available
`utf8::downgrade`	Since 5.8	—	—	Always available
`utf8::encode`	Since 5.8	—	—	Always available
`utf8::is_utf8`	Since 5.8.1	—	—	Always available
`utf8::native_to_unicode`	Since 5.8^[2]	—	—	Always available
`utf8::unicode_to_native`	Since 5.8^[2]	—	—	Always available
`utf8::upgrade`	Since 5.8	—	—	Always available
`utf8::valid`	Since 5.8	—	—	Always available

Notes

Current as of 5.42.
Perl provides other builtin subs which are meant to be used as methods, which aren't documented to be available at all times, or which aren't documented at all. (These are found in in constant::, Internals::, PerlIO::, re::, Tie::Hash::NamedCapture, UNIVERSAL:: and version::). These are deliberately omitted.
The existence of dev versions is ignored.
"Until 5.xx" and "up to 5.xx" are exclusive, meaning they don't include 5.xx.

Footnotes

Experimental warnings were only added in 5.18, but the switch feature was documented to be experimental since 5.16.
While utf8::native_to_unicode and utf8::unicode_to_native have only been documented since 5.22, they've been available since 5.8.

Updates

Added the keywords from the class feature.
Fixed versions for defer.
Fixed versions for finally.
Added availability in CORE::.
is_tainted, export_lexically, builtin::is_tainted and builtin::export_lexically were missing.
Updated for 5.40.
Updated for 5.42.

Comment on Perl named operators and builtin subs introduced since 5.6 Select or Download Code

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Re: Perl named operator and builtin subs introduced since 5.6 by tobyink (Canon) on Sep 27, 2023 at 08:04 UTC
Good table, but maybe it doesn't need to list everything from `builtin` twice? Better to just make a note that they can always be used by their fully-qualified name or imported lexically. Hire me at Toby Ink Ltd or Join my OnlyFans	[reply] [d/l]
Re: Perl named operator and builtin subs introduced since 5.6 by kcott (Archbishop) on Sep 27, 2023 at 10:51 UTC
G'day ikegami, ++ You've obviously put a lot of work into this. I haven't actually gone through and checked everything; however, two stood out, possibly because of the additional text: `given` and `when`. According to the documentation, these became experimental in 5.18 (not 5.16). See "perl5180delta: The smartmatch family of features are now experimental". — Ken	[reply] [d/l] [select]
Re^2: Perl named operator and builtin subs introduced since 5.6 by ikegami (Patriarch) on Sep 28, 2023 at 14:00 UTC
I've mistakenly said the feature became experimental in 5.18 in the past too. But while the experimental warnings were added in 5.18, it was flagged as experimental in 5.16. Quote 5.16's perlsyn, you can say `use feature "switch";` to enable an experimental switch feature. Also, Under the "switch" feature, Perl gains the experimental keywords `given`, `when`, `default`, `continue`, and `break`. Added `break`, `default` and `continue` to the table.	[reply] [d/l] [select]
Re^3: Perl named operator and builtin subs introduced since 5.6 by kcott (Archbishop) on Sep 28, 2023 at 14:22 UTC
++ I never knew that — you learn something every day. Thanks for the info. :-) — Ken	[reply]
Re: Perl named operator and builtin subs introduced since 5.6 by Bod (Parson) on Sep 27, 2023 at 14:14 UTC
Great table - thanks :) I would have expected to see `class` in there as that's new in 5.36 isn't it? I've not used it or investigated it as 5.32 is the latest version I have.	[reply] [d/l]
Re^2: Perl named operator and builtin subs introduced since 5.6 by eyepopslikeamosquito (Archbishop) on Sep 27, 2023 at 22:02 UTC
I would have expected to see `class` in there as that's new in 5.36 isn't it? Good point. I just checked perlclass, and I see keywords: `class`, `field` and `method`. Not sure if attributes `:isa` and `:param` qualify.	[reply] [d/l] [select]
Re^2: Perl named operator and builtin subs introduced since 5.6 by ikegami (Patriarch) on Sep 28, 2023 at 13:56 UTC
5.38. Overlooked. Fixed. Thanks.	[reply]
Re: Perl named operators and builtin subs introduced since 5.6 by ikegami (Patriarch) on Aug 03, 2025 at 17:35 UTC
Updated parent for 5.42.	[reply]
Re: Perl named operators and builtin subs introduced since 5.6 by freonpsandoz (Beadle) on Apr 15, 2025 at 22:56 UTC
Great table, thanks! Is there any way to find out when features other than keywords were added? I'm currently trying to find (1) when ref() began returning 'Regexp' and (2) when class 'Regexp' was added, if that was more recent than (1). Both ref() and Scalar::Util::blessed() return 'Regexp' as of v5.20.2. The referenced 5.38 delta page contains a link to select earlier versions, but it doesn't seem to work; a "raptor not found" error is displayed.	[reply]
Re^2: Perl named operators and builtin subs introduced since 5.6 by choroba (Cardinal) on Apr 16, 2025 at 08:49 UTC
I collect some non-features in Syntax::Construct, but Regexp is not one of them (I might add it, though). `map{substr$_->[0],$_->[1]\|\|0,1}[\\|\|{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^ARGV,3]`	[reply] [d/l]
Re^2: Perl named operators and builtin subs introduced since 5.6 by hippo (Archbishop) on Apr 16, 2025 at 08:19 UTC
A quick perusal through the docs for ref for historical versions of Perl suggests that the Regexp class started being reported in 5.8.9 but this is not mentioned in the 5.8.9 delta AFAICS. Nowadays that really ought to be so long ago that it doesn't matter anyway. 🦛	[reply]
Re^2: Perl named operators and builtin subs introduced since 5.6 by ikegami (Patriarch) on Apr 16, 2025 at 17:23 UTC
It's been that way since at least 5.8.9. ("t" means threaded. Ignore that.) `$ for v in 5.8.9 5.10t 5.12t 5.14t 5.16t 5.18t 5.20t; do echo $v $v/bin/perl -le'print ref( qr/x/ )' done 5.8.9 Regexp 5.10t Regexp 5.12t Regexp 5.14t Regexp 5.16t Regexp 5.18t Regexp 5.20t Regexp` [download]	[reply] [d/l]