What is significance/use of doing void(param); at the start of function?

I was just going thro' source code of Yahoo's Trafic Server It is written in C++.

In almost all methods (from one of modules), they do void(param) on each param that function receive.

(Eg below)

Can someone explain what this could be for ?

int                                                                                                                                                                     
some_method_name(caddr_t addr, size_t len, caddr_t end, 
 int flags)
{  
  (void) end;                                                                                                                                                
  (void) addr;                                                                                      开发者_Go百科                    
  (void) len;                                                                                                                                                   
  (void) end;                                                                                                                                               
  (void) flags;  
  ......
  ....
}

PS: For actual source code, please see methods from http://github.com/apache/trafficserver/blob/trunk/iocore/eventsystem/SocketManager.cc

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This suppresses the "unused argument" warnings. Those statements do nothing, but count as using the argument.