public void visitUnary(JCUnary tree) {
        switch (tree.getTag()) {
        case JCTree.NOT:
            scanCond(tree.arg);
            Bits t = initsWhenFalse;
            initsWhenFalse = initsWhenTrue;
            initsWhenTrue = t;
            t = uninitsWhenFalse;
            uninitsWhenFalse = uninitsWhenTrue;
            uninitsWhenTrue = t;
            break;
        case JCTree.PREINC: case JCTree.POSTINC:
        case JCTree.PREDEC: case JCTree.POSTDEC:
            scanExpr(tree.arg);
            letInit(tree.arg);
            break;
        default:
            scanExpr(tree.arg);
        }
    }