CGAL users discussion list

[Costas Tsirogiannis <>]

Greetings,

I have built a Polyhedron_3 object using Gmpq as NT.  What I want to do is to compute the exact bit-size of the structure. 

This object that I compute contains vertices that were already part of the input plus
vertices constructed from line intersections.  So not all the vertex
coordinates have the same bit size. The Polyhedron_3 class has a member function bytes() which just gives a standard answer: 

sizeof(Vertex_type)*number_of_vertices()+sizeof(Facet_type)*number_of_facets()

But this must not be exact since Gmpq can have an arbitrary number of bits, right? Theoretically, the bit-size of the coordinates of a single vertex in the structure that I compute can be very high (can actually be comparable to the size of the entire input) so this function does not really help me. Any suggestions of how can I compute the exact bit size here or, at least, how can I compute the exact bit-size of a single Gmpq object?

thanks

Constantinos