title: What is a converting constructor in C++ ? What is it for?
body: <p>I have heard that C++ has something called "conversion constructors" or "converting constructors".  What are these, and what are they for?  I saw it mentioned with regards to this code:</p>
  
  <pre><code>class MyClass
  {
    public:
       int a, b;
       MyClass( int i ) {}
  }
  
   int main()
  {
      MyClass M = 1 ;
  }
  </code></pre>