+ distro => {
+ rhel => '7', # v5.16.3
+ centos => '7', # v5.16.3 (2014-07 eol 2024-06)
+ },
+ unicode => '6.1',
+ },
+
+ v5.18 => {
+ new => [
+ ['<code>${^LAST_FH}</code>', 'last read filehandle (used by <code>$.</code>)'],
+ ['<code>/(?[ a + b ])/</code>', 'regex set operations (character substraction <code>-</code>, unions <code>&</code>)', 'experimental::regex_sets'],
+ ['<code>my sub</code>', 'lexical subroutines (also <code>state</code>, <code>our</code>)', 'experimental::lexical_subs'],
+ ['<code>next $expression</code>', 'loop controls allow runtime expressions'],
+ [q"<code>no warnings 'experimental::…'</code>", 'mechanism for experimental features, as of now required for smartmatch'],
+ ],
+ release => '2013-05-18',
+ unicode => '6.2',
+ },
+
+ v5.20 => {
+ new => [
+ ['<code>sub ($var)</code>', 'subroutine signatures', 'experimental::signatures'],
+ ['<code>%hash{…}</code>', 'hash slices return key+value pairs'],
+ ['<code>[]->@*</code>', 'postfix dereferencing (also e.g. <code>$scalar->$*</code> for <code>$$scalar</code>)', 'experimental::postderef'],
+ [q"<code>use warnings 'once'; $a</code>", 'variables $a and $b are exempt from <em>used once</em> warnings'],
+ ],
+ unicode => '6.3',
+ release => '2014-05-27',
+ distro => {
+ debian => 'jessie',
+ },
+ },
+
+ v5.22 => {
+ new => [
+ ['<code>\$alias =</code>', 'aliasing via reference'],
+ ['<code><<>></code>', 'safe <code>readline</code> ignoring open flags in arguments'],
+ ['<code>/()/n</code>', 'flag to disable numbered capturing, turning <code>()</code> into <code>(?:)</code>'],
+ ['<code>/\b{}/</code>', 'boundary types: <em>gcb</em> (grapheme cluster), <em>sb</em> (sentence), <em>wb</em> (word)'],
+ ['<code>&.</code>', '<code>& | ^ ~</code> consistently numeric, dotted operators for strings', 'experimental::bitwise'],
+ [q"<code>use re 'strict'</code>", 'apply stricter syntax rules to regular expression patterns', 'experimental::re_strict'],
+ ['<code>0x.beep+0</code>', q"hexadecimal floating point notation with binary power; <code>printf '%a'</code> to display"],
+ ],
+ unicode => '7.0',
+ release => '2015-06-01',