title: What does int() do in C++?
body: <p>The following code can pass compiling and will print 0 on the console. I saw similar code in STL. Does type int in C++ have a constructor? Is int() a call of some defined function?</p>
  <pre><code>int main()
  {
      int a = int();
      cout &lt;&lt; a &lt;&lt; endl;
      return 0;
  }
  </code></pre>