CGAL users discussion list

[Michael Hoffmann <>]

If you label the vertices of your constrained polygons by component/polygon 
(i.e., the first by 1, the second by 2, etc.), you can just iterate over the 
edges of the triangulation and select those whose endpoints have the same 
label.

It sounds like you know those polygons because they are part of your input. 
If not, you might have to compute them via BFS/DFS or so.
For the labels you can use the vertex_with_info classes.

hth, Michael