Re^3: Dynamic addressing in a hash

[AnomalousMonk]

$config->{$field} //= {};

// is the Logical Defined-Or operator (see perlop), added with Perl version 5.10. So the example from the Camel book
    $val ||= "2"; # Set $val to 2 if it isn't already "true"
exactly translates to
    $val //= "2"; # Set $val to "2" if $val isn't defined