Static Foreach + Marking "compile time" variables

[Chris Katko]

I have a static foreach that goes through the parameter list and 
if it sees a class like "rotate", ideally, I want it to mark a 
boolean "has_rotate=true"

Then simply later on, once I've parsed the list, I pick an output 
path:

     static if(has_rotate && has_position && has_scale)
     {
     //call C function al_draw_rotated_scaled_bitmap(...);
     }

So I pass a bunch of "options" and then based on those options, 
it picks the right function to call instead of me manually 
writing 
draw_fixed_centered_rotated_scaled_colored_compressed_bitmap() 
manually.

The problem is, I can foreach through those parameters all just 
fine... but I can't "set" a marker.

The error message makes perfect sense in retrospect:

      variable has_position cannot be read at compile time

has_position isn't a static/compile-time variable. The question 
is... do they exist in D? Because otherwise, I'll be going from a 
really clean, elegant solution that simply passes through each 
parameter, and then reacts to the combined result, and end up 
with something that has to "step toward" the result, or perhaps, 
test every possible permutation individually--so as to not need 
variables.