According to the spec, it is invalid to define an ander and a setter for the same field of the same type, as the ander leads to the creation of a setter, that will conflict with the user-defined one. Because the implementation currently does not generate setters in this manner, but instead writes their code inline whenever it is needed (https://bugs.webkit.org/show_bug.cgi?id=195925), we won't correctly reject such programs if the ander/setter is never used. The same problem exists for ander/getter.
I believe it is no longer possible for a user to define both an ander and a setter for the same field.
(In reply to Myles C. Maxfield from comment #1) > I believe it is no longer possible for a user to define both an ander and a > setter for the same field. Whoops, disregard this comment, I misread the bug.
WHLSL is no longer relevant.