use B;

my $ref = {}; # get a reference to our object (a hash)
print B::svref_2object($ref)->REFCNT; # prints 1

my $copy = $ref;
print B::svref_2object($ref)->REFCNT; # prints 2

undef $copy;
print B::svref_2object($ref)->REFCNT; # prints 1 again