I have a class implemented in C++. I want to create a shared library that exports that class, but only certain methods. For example, I want to apply internal linkage to all private members.
I have read the problems that anoymous namespaces can cause, so I have discarded that option. Instead, I want to try to use interface segregation, but I don't know how to implement it in a shared library. Let me explain:
Suppose you have the following code:
// MyLib.h
class MyLib {
public:
int fun1() { return _i; }
double fun2() { return _d; }
bool fun3() { return _b; }
private:
int _i;
double _d;
bool _b;
};
I would like to create a shared library that exports the symbol MyLib and only one of its methods, for example fun1.
I can't just mark MyLib as dllexport, since that will export all the class' symbols, including private members. So I want to create an interface with only one method and export it:
class __declspec(dllexport) IMyLib {
virtual int fun1() = 0;
};
class MyLib : public IMyLib {
// Same as above...
};
This schema is explained in the following post: How do I export class functions, but not the entire class in a DLL
Now, my problem is that I don't understand, in the case of being using MyLib.dll, how could you instantiate an IMyLib object, since the class that implements it is hidden (internal linkage), so you can't access it from a shared library.