Question

Given the below classes are in two separate header files and can appear in any order:

//TestB.h
class TestB; //Forward declaration for a later operator= in a centralised header

class TestA
{
    const TestA&operator=(const TestB); //defined in Test.h
};

And:

//TestA.h
class TestA; //Forward declaration for a later operator= in a centralised heaer

class TestB
{
    const TestB&operator=(const TestA); //defined in Test.h
};

How do I avoid the prototype conflict?

Help is appreciated.

I absolutely apologise to everyone! I had intended for there to be references (ampersands in the operator= arguments – I would never pass by copying bar simple PODs) and meant the question solely about prototyping conflicts! I guess it goes to show the importance of proof-reading! I have accepted the answer given the original (my erroneous) context.

I had merely only turned away for a few minutes and was not aware of the fault!

Answer 1

You pass references to the classes as parameters. This way, a class and its member functions can be declared without knowing about the other.

//TestB.h
class TestB; //Forward declaration for a later operator= in a centralised header

class TestA
{
    const TestA&operator=(const TestB &); //defined in TestB.h
};

And:

//TestA.h
class TestA; //Forward declaration for a later operator= in a centralised heaer

class TestB
{
    const TestB&operator=(const TestA *); //defined in TestA.h
};

After this, you’ll have to include both TestA.h and TestB.h in both TestA.cpp and TestB.cpp files to be able to define these member functions.