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copied!<p>Use <code>unique_ptr<T></code> all the time except when you need reference counting, in which case use <code>shared_ptr<T></code> (and for very rare cases, <code>weak_ptr<T></code> to prevent reference cycles). In almost every case, transferrable unique ownership is just fine.</p> <p>Raw pointers: Good only if you need covariant returns, non-owning pointing which can happen. They're not terrifically useful otherwise.</p> <p>Array pointers: <code>unique_ptr</code> has a specialization for <code>T[]</code> which automatically calls <code>delete[]</code> on the result, so you can safely do <code>unique_ptr<int[]> p(new int[42]);</code> for example. <code>shared_ptr</code> you'd still need a custom deleter, but you wouldn't need a specialized shared or unique array pointer. Of course, such things are usually best replaced by <code>std::vector</code> anyway. Unfortunately <code>shared_ptr</code> does not provide an array access function, so you'd still have to manually call <code>get()</code>, but <code>unique_ptr<T[]></code> provides <code>operator[]</code> instead of <code>operator*</code> and <code>operator-></code>. In any case, you have to bounds check yourself. This makes <code>shared_ptr</code> slightly less user-friendly, although arguably the generic advantage and no Boost dependency makes <code>unique_ptr</code> and <code>shared_ptr</code> the winners again.</p> <p>Scoped pointers: Made irrelevant by <code>unique_ptr</code>, just like <code>auto_ptr</code>.</p> <p>There's really nothing more to it. In C++03 without move semantics this situation was very complicated, but in C++11 the advice is very simple.</p> <p>There are still uses for other smart pointers, like <code>intrusive_ptr</code> or <code>interprocess_ptr</code>. However, they're <em>very</em> niche and completely unnecessary in the general case.</p>

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