print map sub{return $_ for 0+shift}->($_), 1, 2, 3;  # 333
print map sub{return $_ for shift}->($_), 1, 2, 3;    # 123
print map sub{return 0+shift}->($_), 1, 2, 3;         # 123
print map sub{return 0+$_ for shift}->($_), 1, 2, 3;  # 123