Socket.IO C++ Client

By virtue of being written in C++, this client works in several different platforms. The examples folder contains an iPhone, QT and Console example chat client! It depends on websocket++ and is inspired by socket.io-clientpp.

Compatibility table

C++ Client version	Socket.IO server version
C++ Client version	1.x / 2.x	3.x / 4.x
2.x (`2.x` branch)	YES	YES, with `allowEIO3: true`
3.x (`master` branch)	NO	YES

Features

100% written in modern C++11
Binary support
Automatic JSON encoding
Multiplex support
Similar API to the Socket.IO JS client
Cross platform

Note: Only the WebSocket transport is currently implemented (no fallback to HTTP long-polling)

Installation alternatives

With CMAKE
Without CMAKE
With VCPKG
With Conan
iOS and OS X
- Option 1: Cocoapods
- Option 2: Create a static library
- Option 3: Manual integration

Quickstart

Full overview of API can be seen here

The APIs are similar to the JS client.

Connect to a server

sio::client h;
h.connect("http://127.0.0.1:3000");

Emit an event

// emit event name only:
h.socket()->emit("login");

// emit text
h.socket()->emit("add user", username);

// emit binary
char buf[100];
h.socket()->emit("add user", std::make_shared<std::string>(buf,100));

// emit message object with lambda ack handler
h.socket()->emit("add user", string_message::create(username), [&](message::list const& msg) {
});

// emit multiple arguments
message::list li("sports");
li.push(string_message::create("economics"));
socket->emit("categories", li);

Items in message::list will be expanded in server side event callback function as function arguments.

Bind an event

Bind with function pointer

void OnMessage(sio::event &)
{

}
h.socket()->on("new message", &OnMessage);

Bind with lambda

h.socket()->on("login", [&](sio::event& ev)
{
    //handle login message
    //post to UI thread if any UI updating.
});

Bind with member function

class MessageHandler
{
public:
    void OnMessage(sio::event &);
};
MessageHandler mh;
h.socket()->on("new message",std::bind( &MessageHandler::OnMessage,&mh,std::placeholders::_1));

Using namespace

h.socket("/chat")->emit("add user", username);