&reftitle.setup;
&reftitle.required;
&no.requirement;
&reference.sockets.configure;
&reftitle.runtime;
&no.config;
&reftitle.resources;
Prior to PHP 8.0.0,
socket_accept, socket_import_stream,
socket_addrinfo_connect, socket_addrinfo_bind,
socket_create_listen, socket_wsaprotocol_info_import and
socket_create returned Socket resources.
Prior to PHP 8.0.0,
socket_addrinfo_lookup returned an array of AddressInfo resources.