<?php

declare(strict_types=1);

function selectValues(
    array $values,
    Closure $accept = static function (int $value): bool {
        return $value >= 0;
    },
): array {
    foreach ($values as $value) {
        if (!is_int($value)) {
            throw new InvalidArgumentException('Expected integer values');
        }
    }

    return array_values(array_filter($values, $accept));
}

echo json_encode(selectValues([-2, 0, 3]), JSON_THROW_ON_ERROR), PHP_EOL;
try {
    selectValues([0, '3']);
    throw new RuntimeException('Mixed input was accepted');
} catch (InvalidArgumentException $error) {
    echo $error->getMessage(), PHP_EOL;
}