# int main(){
#     alias cdouble X;
#     X four = cast(X) (4.0i + 0.4); // OK
#
#     typedef cdouble Y;
#     Y four = cast(Y) (4.0i + 0.4); // ERROR
#
#     return 0;
# }

dmd a.d
> Internal error: ../ztc/el.c 826

Added to DStress as http://dstress.kuehne.cn/run/c/cast_30_A.d http://dstress.kuehne.cn/run/c/cast_30_B.d http://dstress.kuehne.cn/run/c/cast_30_C.d http://dstress.kuehne.cn/run/c/cast_30_D.d http://dstress.kuehne.cn/run/c/cast_30_E.d http://dstress.kuehne.cn/run/c/cast_30_F.d

Thomas