public static bool Is5 <T1, T2, T3, T4, T5, T6, T7, T8>(this IOrType <T1, T2, T3, T4, T5, T6, T7, T8> self, out T5 t5) { if (self.Possibly5() is IIsDefinately <T5> definate) { t5 = definate.Value; return(true); } t5 = default; return(false); }