64-bit and 32-bit integers
<p>Is there a good way to modify a class in C++ so that its integers are 64-bit on a 64-bit system and 32-bit for 32-bit systems? Is there a way to check for that?</p>

<p>The class is something like:</p>

<pre><code>class B{
      public:
            int64_t size();
      private:
            int64_t m_size();
}
</code></pre>
