---
w: bar
---
w:
  - bar
  - bar

##</code><code>##

'foo' =~ /(?<w>\w+)/ && 'foofoo' =~ /\g{w}\g{w}/;

##</code><code>##

'oo' =~ /(?<w>\w+)/ && 'oo' =~ /\g{w}\g{w}/;

##</code><code>##

%+ = ( w => 'oo');
%- = ( w => ['oo']);

##</code><code>##

'oo' =~ /(?<w>\w+)/ && 'oo' =~ /(?<w>\g{w}\g{w})/;  # Which I *think* is possible!

##</code><code>##

%+ = ( w => undef);  # or not existing at all? I'm half hearted...
%- = ( w => []);