sub name {
   my $arg = ref $_[0] ? $_[0] : \do{my $anon = $_[0]};

   # Do stuff.
   $$arg =~ s/^un//;

   return $$arg;
}

##</code><code>##

sub name {
   our $arg;
   local *arg = ref($_[0]) ? $_[0] : \do{my $anon = $_[0]};

   # Do stuff.
   $arg =~ s/^un//;

   return $arg;
}

##</code><code>##

$i = $j = 'unchanged';
name(\$i);
print("i:$i\n");        # i:changed

$i = $j = 'unchanged';
$j = name($i);
print("i:$i, j:$j\n");  # i:unchanged, j:changed

$i = $j = 'unchanged';
$j = name(\$i);
print("i:$i, j:$j\n");  # i:changed, j:changed

##</code><code>##

sub name {
   our $arg;
   local *arg = defined wantarray ? \do{my $anon = $_[0]} : \$_[0];

   # Do stuff.
   $arg =~ s/^un//;

   return $arg;
}

##</code><code>##

name($i);                                  # In place
$j = name($i);                             # Not in place
sub test { name($_[0]) }                   # unknown!!!
sub test { name($_[0]) }   test($i);       # In place
sub test { name($_[0]) }   $j = test($i);  # Not in place