Why would somebody use an #if 1 C preprocessor directive?

Question

I am looking through some C source code and I don\'t understand the following part

#if 1

   typedef u         


        

Answer 1

I put that in my code when I need to test different set of parameters. Usually my product will ship with different defaults than what I can work with in a debug environment, so I put the shipping defaults in a #if 1 and the debug defaults in the #else with a #warning to warn me it's being built with debug defaults.