Benchmarks the impact of type-hinting on PHP variadic functions

variadics-benchmark.php

<?php

$variadics = 1000; // number of objects passed to each variadic function
$iterations = 1000; // number of calls of each function

class Foo {
}

function withoutTypeHinting(...$foos) {
}

function withTypeHinting(Foo ...$foos) {
}

function withManualTypeCheck(...$foos) {
    foreach ($foos as $foo) {
        if (! $foo instanceof Foo) {
            throw new TypeError('Expected instance of Foo');
        }
    }
}

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

function benchmark($function) {
    global $iterations, $foos;

    $t = microtime(true);

    for ($i = 0; $i < $iterations; $i++) {
        $function(...$foos);
    }

    return microtime(true) - $t;
}

$withoutTypeHinting = benchmark('withoutTypeHinting');
$withTypeHinting = benchmark('withTypeHinting');
$withManualTypeCheck = benchmark('withManualTypeCheck');

printf("Without type-hinting: %.6f s\n", $withoutTypeHinting);
printf("With type-hinting: %.6f s\n", $withTypeHinting);
printf("With manual type check: %.6f s\n", $withManualTypeCheck);

printf("Type-hinting overhead: %.1f %%\n", (($withTypeHinting / $withoutTypeHinting) - 1) * 100);
printf("Type-hinting improvement over manual check: %.1f %%\n", (($withManualTypeCheck / $withTypeHinting) - 1) * 100);