Using bitwise operators to store privs

example.php

<?php

$user_rights = 3; // 1+2 (taken from database)

if(rights::can_read($user_rights)) echo "User can read\n";
if(rights::can_write($user_rights)) echo "User can write\n";
if(rights::can_modify($user_rights)) echo "User can modify\n";

class rights {
	static $READ = 1;
	static $WRITE = 2;
	static $MODIFY = 4;
	
	public function can_read($rights) {
		return (($rights & self::$READ)==self::$READ);
	}
	
	public function can_write($rights) {
		return (($rights & self::$WRITE)==self::$WRITE);
	}
	
	public function can_modify($rights) {
		return (($rights & self::$MODIFY)==self::$MODIFY);
	}
}