linux下编程用 编译软件

				// PR c++/5453: Test that we don't assume that the pointer target of a				// reference is non-null just because we know the reference isn't.								// { dg-do run }								struct V { };				struct A: virtual public V { };								A* ap;				A*& apr (ap);								int main ()				{				  V* vp = apr;				}