my $class = ref($class) || $class;

##</code><code>##

my $foo = Foo->new();
my $foo2 = $foo->new();
my $foo3 = Foo::new();

##</code><code>##

+------+-------+-------+
| true | false | final |
+------+-------+-------+
|   0  |   0   |   0   |  Foo::new()
+------+-------+-------+
|   0  |   1   |   1   |  Foo->new()
+------+-------+-------+
|   1  |   x   |   1   |  $foo->new()
+------+-------+-------+

##</code><code>##

package Foo;
sub new {
  my ($class) = @_;
  $class = ref($class) || $class;
  return bless {}, $class;
}

sub test { print "Test" }

package main;
my $foo = Foo::new();
print $foo;
$foo->test();

##</code><code>##

main=HASH(0x180035c)

##</code><code>##

Can't locate object method "test" via package "main" at test.pl line 14.

##</code><code>##

eval { Foo::new() };
ok(!$@, "Foo::new dies when called as a function");