use Data::Dumper;
print Dumper $sub_ref; # prints $VAR1 = sub { "DUMMY" };

##</code><code>##

$ perl
use strict;
use warnings;
use Data::Dumper;
my $coderef = sub { print "hello world\n"; };
print Dumper($coderef);
__END__
$VAR1 = sub { "DUMMY" };

##</code><code>##

$ perl
use strict;
use warnings;
use Data::Dumper;
my $coderef = sub { print "hello world\n"; };
$Data::Dumper::Deparse=1;
print Dumper($coderef);
__END__
$VAR1 = sub {
            use warnings;
            use strict 'refs';
            print "hello world\n";
        };