It is not possible to recover the original source code from a compiled C++ program, especially one built with optimizations enabled. End of story. Not possible.
It is possible to generate functionally equivalent source code from a compiled binary, but it will likely not resemble the original source code in any way.
Long story made short: it is entirely unnecessary to obfuscate C++ code. It doesn't matter if you use a library or write it yourself. Nobody can extract your code from your compiled binary.
