Question

UPDATE: Let me clarify my files and reiterate my question:

main.h

#include "other.h"

class MyClass
{
    public:
    void MyMethod();
    void AnotherMethod();

    OtherClass test;
}

main.cpp

#include "main.h"

void MyClass::MyMethod()
{
    OtherClass otherTemp;     // <--- instantitate OtherClass object
    otherTemp.OtherMethod();  // <--- in this method here, is where I want to also call MyClass::AnotherMethod()
}

void MyClass::AnotherMethod()
{
    // Some code
}

other.h

class OtherClass
{
    public:
    void OtherMethod();
}

other.cpp

#include "other.h"
void OtherClass::OtherMethod()
{
    // !!!! This is where I want to access MyClass::AnotherMethod(). How do I do it?
    // I can't just instantiate another MyClass object can I? Because if you look above in 
    // main.cpp, this method (OtherClass::OtherMethod()) was called from within
    // MyClass::MyMethod() already.
}

So basically what I want is this: you instantiate object A, which in turn instantiates object B, which in turn calls a method that is from object A. I’m sure something like this is possible, but it might just be poor design on my part. Any direction would be greatly appreciated.

Answer 1

Some do one .h/.cpp per class:

my.h

#ifndef MY_H
#define MY_H
#include "other.h"
class MyClass
{
    public:
    void MyMethod();

    OtherClass test;
}
#endif // MY_H

other.h

#ifndef OTHER_H
#define OTHER_H
class OtherClass
{
    public:
    void Othermethod();
}
#endif // OTHER_H

my.cpp

#include "my.h"
void MyClass::MyMethod() { }

other.cpp

#include "other.h"
#include "my.h"
void OtherClass::OtherMethod)()
{
   // (ab)using MyClass...
}

If you’re using only Visual Studio, you could use #pragma once instead of #ifndef xx_h #define xx_h #endif // xx_h.
EDIT: as the comment says, and also the related Wikipedia page, #pragma once is also supported (at least) by GCC.

UPDATE:
About the updated question, unrelated to #include, but more about passing objects around…

MyClass already has an embedded instance of OtherClass, test. So, in MyMethod, it’s probably more like:

void MyClass::MyMethod()
{
    test.OtherMethod();
}

And if OtherMethod needs to access the MyClass instance, pass this instance to OtherMethod either as a reference, or a pointer:

By reference

class OtherClass { public: void OtherMethod(MyClass &parent); }

void MyClass::MyMethod() { test.OtherMethod(*this); }

void OtherClass::OtherMethod(MyClass &parent)
{
   parent.AnotherMethod();
}

By Pointer

class OtherClass { public: void OtherMethod(MyClass *parent); }

void MyClass::MyMethod() { test.OtherMethod(this); }

void OtherClass::OtherMethod(MyClass *parent)
{
   if (parent == NULL) return;  // or any other kind of assert
   parent->AnotherMethod();
}