C++ equivalent of Serialization/Deserialization example

[ashfaq92]

Hi! Thank you for the package. It is really helpful.
First! I am new to c++ so I don't know whether this is right place for question like this:
In your readme examples are provided only with R bindings which are roughly equivalent to example provided in original hnsw library.
But what if somebody wants to do the exact task without 'R'? I am unable to find interface for c++. Original library refers to this library for interfaces in c++ and R. but I could only see interface for R.
It would be really nice if you translate this 'R' example into C++. Thank you!

[jlmelville]

For this project, a vignette on using the C++ would probably be a good idea, but I don't know when I will get round to that. For now, I have commented on your other issue at nmslib/hnswlib#167 and if you look in https://github.com/jlmelville/rcpphnsw/blob/master/src/hnsw.cpp you might be able to piece together what you need.

[LTLA]

Seems to me that the best location for this documentation would be in hnswlib itself, and that RcppHNSW would just point to that... though I must admit that I did write this, so perhaps I'm being hypocritical.