CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

Song Lin wrote:
> Hi,
Hello,

> I want to find connected groups of an alpha_shape_3 and I'm trying to
> use this function: (my thought was first find the neighbors of a vertex
> and then check if one neighbor vertex was linked by an edge to that
> vertex)
>
> template <class OutputIterator>  OutputIterator
> t.finite_adjacent_vertices ( Vertex_handle v, OutputIterator vertices)
> Copies the Vertex_handles of all finite vertices adjacent to v to the
> output iterator vertices. If t.dimension() <0, then do nothing. Returns
> the resulting output iterator. 
> Precondition: 
> v ≠ Vertex_handle(), t.is_vertex(v).
>
> But I don't know how to define an "OutputIterator vertices" type.(Sorry
> if noob) And I can't find an example of this function. Can anyone give
> me an example on how to use this function?
for example:

std::vector<Vertex_handle> adjacent_vertices;
t.finite_adjacent_vertices(v,std::back_inserter(adjacent_vertices));


> By the way, what does "v ≠ Vertex_handle()" mean? 
v must not be a default constructed Vertex_handle, which means that it
must be a valid Vertex_handle.

> Best regards,
> Lin