title: Inline function prototype vs regular declaration vs prototype
body: <p>What's the difference between inline function and then main like so:</p>
  
  <pre><code>inline double cube(double side)
  {
     return side * side * side;
  }
  
  int main( )
  {
      cube(5);
  }
  </code></pre>
  
  <p>vs just declaring a function regularly like:</p>
  
  <pre><code>double cube(double side)
  {
     return side * side * side;
  }
  
  int main( )
  {
      cube(5);
  }
  </code></pre>
  
  <p>vs function prototype?</p>
  
  <pre><code>double cube(double);
  
  int main( )
  {
      cube(5);
  }
  
  double cube(double side)
  {
     return side * side * side;
  }
  </code></pre>