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copied!<blockquote> <p>A deep copy is then: [for loop]</p> </blockquote> <p>You make the client clone the vector explicitly. I'm not sure if this answers your question, but I would suggest a vector of smart pointers so the cloning happens automatically.</p> <pre><code>std::vector<cloning_pointer<Base> > vec; vec.push_back(cloning_pointer<Base>(new Derived())); // objects are automatically cloned: std::vector<cloning_pointer<Base> > vec2 = vec; </code></pre> <p>Of course, you don't want these implicit copies to happen when resizing a vector or something, so you need to be able to distinguish copies from moves. Here is my C++0x toy implementation of <code>cloning_pointer</code> which you might have to adjust to your needs.</p> <pre><code>#include <algorithm> template<class T> class cloning_pointer { T* p; public: explicit cloning_pointer(T* p) { this->p = p; } ~cloning_pointer() { delete p; } cloning_pointer(const cloning_pointer& that) { p = that->clone(); } cloning_pointer(cloning_pointer&& that) { p = that.p; that.p = 0; } cloning_pointer& operator=(const cloning_pointer& that) { T* q = that->clone(); delete p; p = q; return *this; } cloning_pointer& operator=(cloning_pointer&& that) { std::swap(p, that.p); return *this; } T* operator->() const { return p; } T& operator*() const { return *p; } }; </code></pre> <p>Julien: <code>&&</code> is not a "ref of ref", it is an rvalue reference which only binds to modifiable rvalues. See this excellent (but sadly slightly outdated) <a href="http://blogs.msdn.com/vcblog/archive/2009/02/03/rvalue-references-c-0x-features-in-vc10-part-2.aspx" rel="nofollow noreferrer">tutorial</a> and <a href="http://channel9.msdn.com/shows/Going+Deep/VC-10-Stephan-T-Lavavej-and-Damien-Watkins-Inside-STL/" rel="nofollow noreferrer">video</a> for an overview of rvalue references and how they work.</p>

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