Question: how to check if expression is polynomial but coefficients are not complex?

I need to check if an expression is polynomial in x but with coefficients that are either symbolic, or do not include the complex numebr I.

The problem is that maple considers integers and reals complex also.   

type(1,complex) gives true. so I can't use

restart;
type(1+2*x,polynom(Not(complex),x))

Since this gives false. 

I could instead list all the types to be accepted using Or, like this

restart;
type(1+2*x,polynom(Or(float,realcons,rational,integer),x))

But I might overlook something if I have to enumerate every type accepted. It is easier to just exclude complex numbers. 

What is the correct way to tell Maple to check if expression is polynomial in x where coefficients do not have the complex I in them? It it ok if the coefficient are any other numeric value, or a known Maple constant, or a parameter (symbol). I just want to exclude complex numbers.

I know I could do this

restart;
the_poly:=1+2*x;
if not has(the_poly,I) then
   type(the_poly,polynom(anything,x))
else
   print("not allowed");
fi;

But I wanted to learn how to make a type which excludes complex numbers.

Maple 2021.1