title: Does my $_; do anything if $_ is implied
body: <p>I think the answer is yes but I just want to make sure. so if I have</p>
  
  <pre><code>sub something {
      my $_;
      my @array = ...;
      while ( @array ) {
          say;
      }
  }
  </code></pre>
  
  <p>is the <code>my $_;</code> actually effective at lexicalizing the parameter passed to the say?</p>
  
  <p>In this particular case I'm using the <a href="http://search.cpan.org/dist/Dist-Zilla-Plugin-UnusedVarsTests/lib/Dist/Zilla/Plugin/UnusedVarsTests.pm" rel="nofollow noreferrer">DZP::UnusedVarsTests</a> and it's complaining that I haven't used <code>my $_;</code> and I suspect it's a bug since I'm using it in a case where it's implied.</p>