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POtemporary and copy constructor
 

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    <p>With the below program, I tried to experiment with the copy ctor, there is one point which is not clear, when function <code>f( )</code> returns it should use the copy-ctor to create a new object for <code>h2</code>, however I guess that is accomplished by the temporary object which uses the constructer of the object and then makes the copy however the destruction output shows that I am wrong on this reasoning... some clarification is appreciated on this problem ;)</p> <pre><code>#include &lt;fstream&gt; #include &lt;string&gt; using namespace std; ofstream out("HowMany2.out"); class HowMany2 { string name; // Object identifier static int objectCount; public: HowMany2(const string&amp; id = "") : name(id) { ++objectCount; print("HowMany2()"); } ~HowMany2() { --objectCount; print("~HowMany2()"); } // The copy-constructor: HowMany2(const HowMany2&amp; h) : name(h.name) { name += " copy"; ++objectCount; print("HowMany2(const HowMany2&amp;)"); } void print(const string&amp; msg = "") const { if(msg.size() != 0) out &lt;&lt; msg &lt;&lt; endl; out &lt;&lt; '\t' &lt;&lt; name &lt;&lt; ": " &lt;&lt; "objectCount = " &lt;&lt; objectCount &lt;&lt; endl; } }; int HowMany2::objectCount = 0; // Pass and return BY VALUE: HowMany2 f(HowMany2 x) { x.print("x argument inside f()"); out &lt;&lt; "Returning from f()" &lt;&lt; endl; return x; } int main() { HowMany2 h("h"); out &lt;&lt; "Entering f()" &lt;&lt; endl; HowMany2 h2 = f(h); } </code></pre> <p>Output </p> <pre><code>HowMany2() h: objectCount = 1 Entering f() HowMany2(const HowMany2&amp;) h copy: objectCount = 2 x argument inside f() h copy: objectCount = 2 Returning from f() HowMany2(const HowMany2&amp;) h copy copy: objectCount = 3 ~HowMany2() h copy: objectCount = 2 // Confused here !!!! why not h copy copy ~HowMany2() h copy copy: objectCount = 1 ~HowMany2() h: objectCount = 0 </code></pre>
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