用于进行gcc测试

				// { dg-do compile }				// { dg-options "-Wunused-parameter" }								// Copyright (C) 2003 Free Software Foundation, Inc.				// Contributed by Nathan Sidwell 15 Sep 2003 				// Origin: yotamm@mellanox.co.il												// PR c++/9848. Missing warning								struct C1 {				  // Only use in-charge ctor				  C1(int bi) {}  // { dg-warning "unused parameter" "" }				};				struct C2 {				  // Only use base ctor				  C2(int bi) {}  // { dg-warning "unused parameter" "" }				};								struct D : C2				{				  D (int) : C2 (1) {}				};								void show_compile_warning ()				{				  C1 c1 (1);				  				  D d (1);				}