C ++ - 基类和私有头

Question

I'm writing a library in C++ and have a class hierarchy like this:

message.h file (in ./mylib/src)

class Message
{
};

request.h file (in ./mylib/include/mylib)

#include "message.h"

class Request : public Message
{
};

response.h file (in ./mylib/include/mylib)

#include "message.h"

class Response : public Message
{
};

I want everything in my mylib/src folder to be hidden from user and want only to distrubute files in mylib/include. But the problem is as both requst.h and response.h #include message.h so user will get a "No such file" error when #including request.h and response.h. Is there a way to work around this problem?

Answer 1

You can simply provide a public interface for Message and keep the actual class hidden:

class IMessage
{
    Message* pImpl;
};

Distribute this header and use a forward declaration for Message .

Another option would be to use composition instead of inheritance (you'll need pointers as members, not the full object).

Answer 2

If you want to be able to use Response and Request you need to include the header files where they are declared. That is why you should put those headers in the public include folder.

Answer 3

基类应该公开分发，否则你将不得不编写序列化/反序列化的机制。