struct SMaterial
{
    union
    {
        struct
        {
            bool Wireframe;
            bool PointCloud;
            bool GouraudShading;
            bool Lighting;
            bool ZBuffer;
            bool ZWriteEnable;
            bool BackfaceCulling;
            bool FogEnable;
        };
        bool Flags[ 8 ];
    };
}; 

int _tmain(int argc, _TCHAR* argv[])
{
    SMaterial sm;
    sm. // <<== only "Flags" shown
	return 0;
}