no warnings 'utf8';
use Encode qw(decode is_utf8);

$r = "\xc2\xa9\xc2\xae\xe2\x84\xa2";
print "Raw \$r      : ", $r, 
      " - ", (is_utf8($r)?"is":"is not"), " utf8\n";

$u = decode('utf8',  "\xc2\xa9\xc2\xae\xe2\x84\xa2");
print "UTF8 \$u     : ", $u, 
      " - ", (is_utf8($u)?"is":"is not"), " utf8\n";

$x = join('', $r, $u);
print "Join(\$r, \$u): ", $x, 
      " - ", (is_utf8($x)?"is":"is not"), " utf8\n";

$e = decode('utf8', $r);
print "Encd \$e     : ", $e, 
      " - ", (is_utf8($e)?"is":"is not"), " utf8\n"; 

$y = join('', $e, $u);
print "Join(\$e, \$u): ", $y, 
      " - ", (is_utf8($y)?"is":"is not"), " utf8\n";