Emulated Overloading

overloading.php

<?php

/*
 * DISCLAIMER: This is a benchmark, not a use case. Please forgive the rudimentary example below.
 *
 * The following demonstrates a relatively common implementation of overload emulation.
 *
 * The benchmark measures the overhead in counting the anonymous arguments
 * and delegating the the respective function.
 *
 * With an input of 10000000 iterations, this PC gives the following results:
 *
 * DIFFERENT FUNCTIONS: 2
 * OVERLOADED: 13
 *
 * With proper overloading, the "add_2" and "add_3" function would be simply:
 *
 * function add($a, $b) {}
 * function add($a, $b, $c) {}
 *
 * With a performance similar to, but slightly degraded from 2 seconds, depending on the number of
 * instructions saved internally.
 */

function add_2($a, $b)
{
    return $a + $b;
}

function add_3($a, $b, $c)
{
    return $a + $b + $c;
}

function overloaded(... $args)
{
    $count = count($args);

    if (2 === $count) {
        return add_2($args[0], $args[1]);
    } elseif (3 === $count) {
        return add_3($args[0], $args[1], $args[2]);
    }
}

$count = (int) $argv[1];

// DIFFERENT FUNCTIONS
$time = time();
for ($i = 0; $i < $count; $i++) {
    add_2($i, 1);
    add_3($i, 1, 2);
}
echo 'DIFFERENT FUNCTIONS: '. (time() - $time) . PHP_EOL;

// OVERLOADED
$time = time();
for ($i = 0; $i < $count; $i++) {
    overloaded($i, 1);
    overloaded($i, 1, 2);
}
echo 'OVERLOADED: '. (time() - $time) . PHP_EOL;