title: How to concatenate two or more Integers using Macros?
body: <p>If a=1, b=2, c=3... I would like to write a macro which concatenates them like this 123.
  But when I try this:</p>
  
  <pre><code>#include&lt;stdio.h&gt;
  #define cat(a,b,c) a##b##c
  
  int main()
  {
  int a=1,b=2,c=3,d;
  d=cat(1,2,3); //Works
  d=cat(a,b,c); // Returns an error...How to make this work?
  return 0;
  }
  </code></pre>