title: C++ function declaration in C++, type cast
body: <p>I found there is an interesting syntax in C++ function declaration and its defination. for example,</p>
  
  <pre><code>bool myLess(const int&amp; x=int(),const int&amp; y=int());
  </code></pre>
  
  <p>how to understand the "=int()" in this declaration?</p>
  
  <p>I guess its effect is to transform the input actual arguments of other types into  int type, it is surely so. I can call this function as</p>
  
  <pre><code>          double x1{3.5}, x2{4.5};
            bool b = myLess(x1,x2);
  </code></pre>
  
  <p>but I cannot understand this syntax, can anyone give me some answer? where can i find this syntax in ISO C++ standard? </p>