How to print unicode characters (no library)?

[Kagamin]

D strings are plain arrays without any text-specific logic, the 
element is called code unit, which has a fixed size, and the 
array length specifies how many elements are in the array. This 
model is most adequate for memory correctness, i.e. it shows what 
takes how much memory and where it will fit. D doesn't impose 
fixed interpretations like characters or code points, because 
there are many of them and neither is the correct one, you need 
one or another in different situations. Linux console one example 
of such situation: it doesn't accept characters or code points, 
it accepts utf8 code units, using anything else is an error.