Upgrading from 3.1.4 to 3.1.5 throws warning when using typehinting

[c0deright]

Since upgrading from 3.1.4 to 3.1.5 we're getting warning

PHP Warning: Declaration of MemcachedWrapper::addServers(array $a_servers): bool should be compatible with Memcached::addServers($servers) in test.php on line 47

<?php

/**
 * Class MemcachedWrapper
 * @package App\System\Memcached
 */
class MemcachedWrapper extends \Memcached
{
    /**
     * Prevent adding of new servers as duplicates
     *
     * @param array $a_servers
     *
     * @return bool
     */
    public function addServers(array $a_servers): bool
    {
        if (TRUE === empty($this->getServerList()))
        {
            return parent::addServers($a_servers);
        }

        return FALSE;
    }

    /**
     * Prevent adding of new server as duplicate
     *
     * @param string $s_host
     * @param mixed  $m_port
     * @param int    $i_weight
     *
     * @return bool
     */
    public function addServer($s_host, $m_port, $i_weight = 0): bool
    {
        foreach ($this->getServerList() as $server)
        {
            if ($server['host'] === $s_host && (int) $server['port'] === (int) $m_port)
            {
                return FALSE;
            }
        }

        return parent::addServer($s_host, $m_port, $i_weight);
    }
}

$m = new MemcachedWrapper();
$m->addServer('localhost', 11211);

print_r($m->getVersion());

% php test.php
PHP Warning:  Declaration of MemcachedWrapper::addServers(array $a_servers): bool should be compatible with Memcached::addServers($servers) in test.php on line 47
Array
(
    [localhost:11211] => 1.6.7
)

Server

• memcached-1.6.7

Client

PHP Version => 7.1.33-19+ubuntu16.04.1+deb.sury.org+1
PHP API => 20160303
PHP Extension => 20160303

memcached

memcached support => enabled
Version => 3.1.5
libmemcached version => 1.0.18
SASL support => yes
Session support => yes
igbinary support => yes
json support => yes
msgpack support => yes

Directive => Local Value => Master Value
memcached.compression_factor => 1.3 => 1.3
memcached.compression_threshold => 2000 => 2000
memcached.compression_type => fastlz => fastlz
memcached.default_binary_protocol => Off => Off
memcached.default_connect_timeout => 0 => 0
memcached.default_consistent_hash => Off => Off
memcached.serializer => php => php
memcached.sess_binary_protocol => On => On
memcached.sess_connect_timeout => 0 => 0
memcached.sess_consistent_hash => On => On
memcached.sess_consistent_hash_type => ketama => ketama
memcached.sess_lock_expire => 0 => 0
memcached.sess_lock_max_wait => not set => not set
memcached.sess_lock_retries => 5 => 5
memcached.sess_lock_wait => not set => not set
memcached.sess_lock_wait_max => 150 => 150
memcached.sess_lock_wait_min => 150 => 150
memcached.sess_locking => On => On
memcached.sess_number_of_replicas => 0 => 0
memcached.sess_persistent => Off => Off
memcached.sess_prefix => memc.sess.key. => memc.sess.key.
memcached.sess_randomize_replica_read => Off => Off
memcached.sess_remove_failed_servers => Off => Off
memcached.sess_sasl_password => no value => no value
memcached.sess_sasl_username => no value => no value
memcached.sess_server_failure_limit => 0 => 0
memcached.store_retry_count => 2 => 2

[GrahamCampbell]

I think this is correct. You cannot restrict the parameter type to array. It is a bug that PHP was not warning you about this before. Parameters must be contravariant in PHP.

[c0deright]

I think this is correct. You cannot restrict the parameter type to array. It is a bug that PHP was not warning you about this before. Parameters must be contravariant in PHP.

According to https://github.com/php-memcached-dev/php-memcached/blob/master/php_memcached.stub.php#L55 you're declaring the function as

public function addServers(array $servers): bool {}

which is exactly what we're using in the class that extends Memcached class.

Can you elaborate why this WARNING is correct, please?

[marcos-devarts]

Sorry @GrahamCampbell, but I have the same problem as @c0deright, and I agree with him: the function signature includes array $servers in:

• The first version in memcached-api.php, 2009.
• Memcached::addServers documentation on php.net
• The first version of php_memcached_stub.php, 2020
  and the current version.