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    <p>To solve the problem which you have mentioned, although you are going in right direction, but you are doing it the wrong way. This is what you would need to do</p> <ul> <li>Define a base class (which you are already doing) with virtual functions which would be overridden by derived classes <code>Enemy</code> and <code>Civilian</code> in your case.</li> <li>You need to choose a proper container with will store your object. You have taken a <code>std::vector&lt;IActor&gt;</code> which is not a good choice because <ul> <li>Firstly when you are adding objects to the vector it is leading to object slicing. This means that only the <code>IActor</code> part of <code>Enemy</code> or <code>Civilian</code> is being stored instead of the whole object.</li> <li>Secondly you need to call functions depending on the type of the object (<code>virtual functions</code>), which can only happen if you use pointers. </li> </ul></li> </ul> <p>Both of the reason above point to the fact that you need to use a container which can contain pointers, something like <code>std::vector&lt;IActor*&gt;</code> . But a better choice would be to use <code>container of smart pointers</code> which will save you from memory management headaches. You can use any of the smart pointers depending upon your need (but not <code>auto_ptr</code>)</p> <p>This is what your code would look like</p> <pre><code>// somewhere during init std::vector&lt;some_smart_ptr&lt;IActor&gt; &gt; ActorList; ActorList.push_back(some_smart_ptr(new Enemy())); ActorList.push_back(some_smart_ptr(new Civilian())); </code></pre> <p>and</p> <pre><code>// main loop while(!done) { BOOST_FOREACH(some_smart_ptr&lt;IActor&gt; CurrentActor, ActorList) { CurrentActor-&gt;Update(); CurrentActor-&gt;Draw(); } } </code></pre> <p>Which is pretty much similar to your original code except for smart pointers part</p>
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    1. POWhat would be the safest way to store objects of classes derived from a common interface in a common container?
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    1. USYogesh Arora
    1. USYogesh Arora
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    1. COspecifically you want a smart pointer with copy semantics
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      1. USjk.
    2. COyup i agree with that
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      1. USYogesh Arora
    3. COI like your approach as it looks very clean for a pointers based approach. However, as others have pointed out, what I want to do is probably better done using Boost Pointer Containers as they indeed appear to be made for just what I want to achieve. I will try your approach should that fail. Or do you see any reason *not* to use Boost Pointer Containers?
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