Compiling error on linux (UNREFERENCED_PARAMETER) about l2packets HOT 3 CLOSED

add to L2BasePacket.h
//---------------------
#ifndef UNREFERENCED_PARAMETER 
#define UNREFERENCED_PARAMETER(x) (x); 
#endif
//----------------------

UNREFERENCED_PARAMETER is defined in WinAPI in WinNT.h:
#define UNREFERENCED_PARAMETER(P) (P)
It should stop warnings about unreferenced parameters

But unlike msvc, my gcc-4.3.2 prints warnings for code:
void func( int x ) { x; }
something like 'statement has no effect'
so this macro is useless under linux? O_o