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run code in 150+ php & hhvm versions
Bugs & Features
<?php preg_match('/(?>[A-Za-z]+)([A-Za-z]+)/', 'FooBar', $m); var_dump($m); preg_match('/([A-Za-z]++)([A-Za-z]+)/', 'FooBar', $m); var_dump($m);
based on vRi6A
Output for 4.3.0 - 7.1.0
array(0) { } array(0) { }