#!/usr/bin/perl
use strict;
use warnings;
use Test::More qw(no_plan);

my $x1 = 44.7;
my $x2 = 44.9-0.2;

is($x1,$x2, "44.7 is 44.9-0.2"); #succeeds. because is uses the eq operator...
cmp_ok($x1,'==',$x2, "44.7 == 44.9-0.2"); # fails. but the diagnostic isn't real helpful.