Actually, the following are equivalent:

my $object = MyClass->new;
my $object = new MyClass;
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The second is referred to as the "indirect object syntax". It's generally discouraged because it can confuse the perl parser.

Actually, the first syntax isn't fantastic either, because...

package MyClass    { sub new { bless []=>shift } }
package OtherClass { sub new { bless []=>shift } }
package main
{
   sub MyClass () { return 'OtherClass' }
   my $object = MyClass->new;
   print ref $object;
}
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Now, what does that print? You might expect $object to be an instance of MyClass, but it's actually an instance of OtherClass.

The following are unambiguous ways to call a constructor:

my $object = MyClass::->new;
my $object = 'MyClass'->new;
my $class = 'MyClass'; my $object = $class->new;
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Back to the topic of the indirect object syntax... there's a module called indirect that allows you to convert uses of indirect object syntax into fatal errors.