production ready

main.php

<?php

class a
{
    private function __construct()
    {
        var_dump("sasaassasasssaassaas");
    }

    public function is_numeric($any)
    {
        return is_numeric($any);
    }
}

var_dump(([(fn() => new static)(...)->bindTo(...)(null, a::class)(...)(...)(...)(...)(), 'is_numeric'])(12));

class b
{
    public function is_numeric($any)
    {
        return is_numeric($any);
    }

    public static function is_numeric_static($any)
    {
        return is_numeric($any);
    }
}

$aa = ['b', 'is_numeric_static'];
var_dump($aa(12));
var_dump(([new b, 'is_numeric'])(12));
var_dump(([new b, 'is_numeric_static'])(12));
var_dump((['b', 'is_numeric_static'])(12));
var_dump((get_defined_vars()['aa'])(12));
(function () use ($aa) {
    var_dump((current(get_defined_vars()))(12));
})();