Benchmark - array with instanceof vs. typehinted variadic argument vs. separate iterator class

composer.json

{
  "require": {
    "phpunit/php-timer": "~1.0"
  }
}

test.php

<?php
declare(strict_types=1);

include(__DIR__ . '/vendor/autoload.php');

class Foo {
	public $bar = 1;
}

class Foos implements \IteratorAggregate, \Countable {

	private $foos;

	public function __construct(array $foos) {
		foreach ($foos as $foo) {
			if (!$foo instanceof Foo) {
				throw new \TypeError();
			}
		}

		$this->foos = $foos;
	}

	public function getFoos(): array {
		return $this->foos;
	}

	/**
	 * @return \ArrayIterator|UserType[]
	 */
	public function getIterator() {
		return new \ArrayIterator($this->foos);
	}

	public function count(): int {
		return count($this->foos);
	}
}

function testArray(bool $use_array_map, array $foos): array {
	foreach ($foos as $foo) {
		if (!$foo instanceof Foo) {
			throw new \TypeError();
		}
	}

	if ($use_array_map) {
		$new_foos = array_map(
			function (Foo $foo): Foo {
				return new Foo($foo->bar + 1);
			},
			$foos
		);
	} else {
		$new_foos = [];
		foreach ($foos as $foo) {
			$new_foos[] = new Foo($foo->bar + 1);
		}
	}

	return $new_foos;
}

function testVariadic(bool $use_array_map, Foo ...$foos): array {
	if ($use_array_map) {
		$new_foos = array_map(
			function (Foo $foo): Foo {
				return new Foo($foo->bar + 1);
			},
			$foos
		);
	} else {
		$new_foos = [];
		foreach ($foos as $foo) {
			$new_foos[] = new Foo($foo->bar + 1);
		}
	}

	return $new_foos;
}

function testIterator(bool $use_array_map, Foos $foos): Foos {
	if ($use_array_map) {
		$new_foos = array_map(
			function (Foo $foo): Foo {
				return new Foo($foo->bar + 1);
			},
			iterator_to_array($foos)
		);
	} else {
		$new_foos = [];
		foreach ($foos as $foo) {
			$new_foos[] = new Foo($foo->bar + 1);
		}
	}

	return new Foos($new_foos);
}

function testVariadicFunction(Foo ...$foos) {
	return $foos;
}

$foos = [];
for ($i = 0; $i < 500000; $i++) {
	$foos[] = new Foo();
}

$test = $argv[1] ?? 'array';
$use_array_map = isset($argv[2]) ? true : false;

switch ($test) {
	case 'array':
		$foos = testArray($use_array_map, $foos);
		break;

	case 'variadic':
		$foos = testVariadic($use_array_map, ...$foos);
		break;

	case 'iterator':
		$foos = testIterator($use_array_map, new Foos($foos));
		break;
        
	case 'vfunction':
		$foos = testVariadicFunction(...$foos);
		break;
}

printf("%s\n", PHP_Timer::resourceUsage());

Here is results

➜   php -v
PHP 7.1.5 (cli) (built: May 13 2017 13:28:23) ( NTS )
Copyright (c) 1997-2017 The PHP Group
Zend Engine v3.1.0, Copyright (c) 1998-2017 Zend Technologies
    with Zend OPcache v7.1.5, Copyright (c) 1999-2017, by Zend Technologies
➜   php test.php array
Time: 204 ms, Memory: 96.01MB
➜   php test.php variadic
Time: 217 ms, Memory: 119.76MB
➜   php test.php iterator
Time: 293 ms, Memory: 112.01MB
➜   php test.php vfunction
Time: 110 ms, Memory: 71.76MB