Dear sir,

I have two threads using the same polygon.
One thread is modifying the polygon. 
And I want the other thread to use the modified polygon,
so I need to define the polygon as volatile.
However, when I use *(volatile polygon*)&mypolygon,
I get some error as follows:
error: no type named ‘type’ in ‘struct boost::geometry::dimension<volatile boost::geometry::model::polygon<boost::geometry::model::d2::point_xy<double> > >’.

What's wrong with this usage?

Best regards,
Guo Long