About this project, I use the lib found on the github as I mentioned before. It works well and quite easy to adjust the codes for my own requirements.
One bug I found about this lib is it do not delete the resource if clients disconnected(maybe not a big issue for the author so he did not fix it), you need to handle that part by yourself. If you need to have multiple keys, I suggest boost::multiindex, although the api is a bit complicated, it is easy to use and help us write clean codes.
If my customers allowed, I would put the version after alternate to github.