Mutual Inclusion of header files and class members c++

Question

I have the following situation:

3 C++ Classes:

ClassA ClassB ClassC

class A
{
    int member;
    B bmember;
};


class B
{
    int member;
    std::shared_ptr <A> amember;
    C cmember;
};

class C
{
    int member;
    std::shared_ptr <A> amember;
};

Each class implements functions that use the public member functions of the of other class. The file structure is as follows:

class1.cpp, class1.hpp includes class2.hpp

class2.cpp, class2.hpp includes class3.hpp and class1.hpp

class3.cpp, class3.hpp includes class1.hpp

Using #pragma once in each header file saves me from having an infinite recursive loop. I am building a cmake project that builds each class into a library. They each target eachother.

However because there are no forward declarations of ClassB to ClassA I receive "not declared errors"

I need each class to have a reference to the others, and still be able to access their functions. How can I achieve this? I am willing to merge files if I need too, but I would like to make the libraries modular and not all in one file.