Include Class in Source File Rather Than Header
<p>I have 3 classes:</p>

<p>ClassA.h</p>

<pre><code>ClassA
{
    public:
        ClassA();
};
</code></pre>

<p>ClassB.h</p>

<pre><code>#include "ClassA.h"

classB
{
    public:
        ClassB();

    private:
        ClassA m_classA;
};
</code></pre>

<p>ClassC.h</p>

<pre><code>#include "ClassB.h"

ClassC
{
    public:
        ClassC();

    private:
        ClassB m_classB;
};
</code></pre>

<p>ClassC needs ClassB and ClassB needs ClassA. ClassC doesn't need ClassA so should I put the #include "ClassA.h" that's inside the ClassB header inside the source file and make a global object or is there a better way?</p>

<p>ClassB.cpp</p>

<pre><code>#include "ClassB.h"
#include "ClassA.h"

ClassA g_classA;
</code></pre>
