brew install php70
git clone -b NON_BLOCKING_IO_php7 https://github.com/websupport-sk/pecl-memcache.git
cd pecl-memcache
phpize
./configure
make && make install
vi /usr/local/etc/php/7.0/php.ini
Add extension=memcache.so
under the extensions section.
now it's just
brew install libmemcached
brew install pkg-config
pecl install memcached
restart webserver / php