How to create a C++ library to sell it and Demo trial mode

I have created some C++ classes. I want to sell them as a library. What should I do so that no one can see how I implemented but he can use it. Also I want to create a demo tria开发者_如何学Cl version of the library which expires after some time, how can I do this.

Thanks Tarun

If you distribute them compiled (dll or so extensions for example), then it won't be easy to see how you implemented them.

I gave an answer here that might be helpful to create a trial version with time expiration.

If you're really paranoid, you can run your code through a C++ obfuscator.