use warnings;
use strict;
use Data::Dump;

my $s = "a aa aaa aaaa";

$s =~ /(?<a>a+) (?<a>a+) (?:(?<a>a+)bbb)?/;

dd \%+;
dd \%{^CAPTURE};

dd \%-;
dd \%{^CAPTURE_ALL};

tie my %hash, "Tie::Hash::NamedCapture", all => 1;
dd \%hash

__END__

{
  # tied Tie::Hash::NamedCapture
  a => "a",
}
{
  # tied Tie::Hash::NamedCapture
  a => "a",
}
{
  # tied Tie::Hash::NamedCapture
  a => ["a", "aa", undef],
}
{
  # tied Tie::Hash::NamedCapture
  a => "a",
}
{
  # tied Tie::Hash::NamedCapture
  a => ["a", "aa", undef],
}