ARM grammar states that an assignment-expression IS
     unary-expression assignment-operator assignment-expression

However I see a lot of commercial code (such as USL library) wherein
an assignment to a cast-expression is done.  Since a cast-expression
cannot reduce to a unary-expression, my parser gets a syntax error
on the "=" operator.  So shouldn't assignment-expression be
     cast-expression assignment-operator assignment-expression

Thanks for any replies.