C++ GLR parser const values in user rules

Hello,

I am trying to implement a VHDL parser using Bison/C++ combination and I am having problems with generated code. Specifically, the:

yyuserAction()

function.

I am unable to compile the code, because all rhs values for each rule are cast as:

static_cast<glr_stack_item const*>(...)

I would like to move the values into resulting struct, but the I am unable to because of "constness".

Are all those rhs values const because of GLR (i.e, multiple stacks)?

Oh, I am using Bison 3.8.2 and "glr2.cc" skeleton.

Thanks,
Martin.