Run time resolution c++ Namespace conflicts

File1.h

// Declaration  
Class A  
{  
void Func();  
}  
//Along with some other stuff  

File1.cpp

//Definition  
A::Func()  
{  
} 

// Along with some o开发者_StackOverflow中文版ther stuff 

File2.h

class A  
{  
 void Func();  
}  

File2.cpp

// Definition  
File2::A::Func()  
{  
}  

File3.cpp  
#include "File1.h"  
#include "File2.h"  
//   
Invokes Func()  

Main1.cpp Main2.cpp

Main1.cpp File3.cpp and File2.cpp are build together

Main1.cpp File3.cpp and File1.cpp are build together

I want to invoke Func() depending different linkage

But, it gives me compile time error.

How should I get around compile time error?

Is there standard way to get around above problem?

If I use namespace for File1 and File2 then I will not be able to invoke dynamically. Note: I can not change File1.h

Unlike Java (for one example), which enforces a 1:1 correspondence between classes and file names, C++ basically ignores file names completely. As such, to resolve the conflict between your two classes (both named A), you can use namespaces:

//file1.h:
class A 
    void Func();
};

//file1.cpp:
A::Func() {}

//file2.h:
namespace f2 { 
class A { 
    void Func();
};
}

// file2.cpp:

namespace f2 { 
    A::Func() {}
}

// main.cpp
#include "file1.h"
#include "file2.h"

int main() {
    A f1a;
    f2::A f2a;

    f1a.Func();  // invokes Func declared in file1.h, which is in global namespace
    f2a.Func();  // invokes Func declared in file2.h, which is in namespace f2
    return 0;
}

It's not clear what you mean by invoking dynamically. Dynamic invocation sounds a lot like using a polymorphic function, which would require a common base class:

struct base { 
    virtual void Func() = 0;
};

struct A1 : public base { 
    virtual void Func() {}
};

struct A2 : public base { 
    virtual void Func() {}
};

int main() { 
    A1 a1;
    A2 a2;
    base *b[2] = { &a1, &a2 };

    b[0]->Func(); // invokes A1::Func()
    b[1]->Func(); // invokes A2::Func()
    return 0;
}