D check type is pointer

original text

void main() {
    
  char accepted_type;
  char* non_accepted_type;

  if (__traits(isPointer, typeof(accepted_type))) {
    
    //  Type... Is not accepted 
  }

 else {
     /* It's not a pointer , Accept */ }

  if (__traits(isPointer, typeof(non_accepted_type))) {
    
    // Type... Is not accepted 
  }

 else {
     /* It's not a pointer , Accept */ }
}

You can see Source code , here :

enum bool isPointer(T) = is(T == U*, U) && __traits(isScalar, T);

You can use is() expression :

if (is(typeof(accepted_type) == T*, T))
{
    // If the accepted type matches T*, be T It's the type 
    //  It's a pointer 
}

Adamic is expression