Question

I’m a noob in C++ meta programming and I understand that I must place implementation of class in header file for convention. But when you want to purchase an package you need to separate the header and the implementation.

Now, Is there a way to do this?

Note: I know about ‘export’ keyword and read this page!

Answer 1

There are several vendors providing general templates for purchase (BTW, I assume you want to sell the template code rather than purchase it) and they simply ship the source. The license agreement states that you can’t distribute or modify the code. Done.

If that’s not good enough for your needs here are a few things you can do:

• Factor code into components with minimal dependency on template arguments. This may yield parts of the code you can put into a readily compiled object because they don’t depend on template arguments or you can preinstantiate the code.
• Obfuscating the code may be one way to go. In this context it is worth noting that a reason given for the absense of an “Obfuscated C++ Contest” by Steve Clamage was: “That would be like shooting fish in a barrel.”
• Create a service where customers upload the class declarations needed for template instantiation and get back the compiled instantiation. Of course, if you don’t trust the customers they have no reason to assume that you might be trustworthy.
• Wait for the next revision of the standard which hopefully has some sort of module support helping with this issue. I wouldn’t bet too high on this, however.

Personally, I wouldn’t bother: from feedback I get back on my code it seems that despite documentation and explanations nobody is prepared to touch it. I think it is rather readable..,