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    <p>A virtual constructor is not possible but virtual destructor is possible. Let us experiment....</p> <pre><code>#include &lt;iostream&gt; using namespace std; class Base { public: Base(){ cout &lt;&lt; "Base Constructor Called\n"; } ~Base(){ cout &lt;&lt; "Base Destructor called\n"; } }; class Derived1: public Base { public: Derived1(){ cout &lt;&lt; "Derived constructor called\n"; } ~Derived1(){ cout &lt;&lt; "Derived destructor called\n"; } }; int main() { Base *b = new Derived1(); delete b; } </code></pre> <p>The above code output the following:</p> <pre class="lang-none prettyprint-override"><code>Base Constructor Called Derived constructor called Base Destructor called </code></pre> <p>The construction of derived object follow the construction rule but when we delete the "b" pointer(base pointer) we have found that only the base destructor is call.But this must not be happened. To do the appropriate thing we have to make the base destructor virtual. Now let see what happen in the following:</p> <pre><code>#include &lt;iostream&gt; using namespace std; class Base { public: Base(){ cout &lt;&lt; "Base Constructor Called\n"; } virtual ~Base(){ cout &lt;&lt; "Base Destructor called\n"; } }; class Derived1: public Base { public: Derived1(){ cout &lt;&lt; "Derived constructor called\n"; } ~Derived1(){ cout &lt;&lt; "Derived destructor called\n"; } }; int main() { Base *b = new Derived1(); delete b; } </code></pre> <p>The output changed as following:</p> <pre class="lang-none prettyprint-override"><code>Base Constructor Called Derived constructor called Derived destructor called Base Destructor called </code></pre> <p>So the destruction of base pointer(which take an allocation on derived object!) follow the destruction rule i.e first the derived then the base. On the other hand for constructor there are nothing like virtual constructor.</p>
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    1. POWhen to use virtual destructors?
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    1. USDaniel Carvalho
    1. USTunvir Rahman Tusher
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    1. CO" virtual constructor is not possible" means you need not write virtual constructor by your own. Construction of derived object must follow the chain of construction from derived to base. So you need not write the virtual keyword for your constructor. Thanks
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      1. USTunvir Rahman Tusher
    2. CO@Murkantilism, "virtual constructors cannot be done" is true indeed. A constructor cannot be marked virtual.
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    3. CO@cmeub, But there is an idiom to achieve what you would want from a virtual constructor. See http://www.parashift.com/c++-faq-lite/virtual-ctors.html
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