2.54 Can I perform a boolean operation between a NURBS object and a mesh?

I have created a NURBS glass (by generating a curve and then adding a 360 ‘screw’ modifier to it). This gives me a glass object. I would like to add some liquid into the glass, so I thought that the easiest way would be to generate a cube mesh and perform a boolean operation with the glass object (and delete the non-liquid portions of the cube).

When I go the the boolean modifications option, nothing is available! I cannot for the life of me figure out how to get this done. Are boolean operations even possible between NURBS objects and meshes?

Thanks for your help.

The boolean modifier works only on mesh objects. You’ll have to convert to a mesh with Alt+C