I used the constant module, use constant DEBUG => 1;. The advantage of this over $DEBUG is supposed to be that Perl will eliminate the "and" if DEBUG => 0;

I'm pretty sure that DEBUG and will be optimized out when DEBUG is 0.

Likewise, I'm pretty sure that if DEBUG would be optimized out when DEBUG is 0.

I'm guessing it's the use constant DEBUG part that other people think is not simple.