CGAL users discussion list

[Song Lin <>]

Hi,

I'm trying to mark the edges of an alpha shape using Unique_hash_map.
Part of my codes are:

typedef Alpha_shape_3::Edge Edge;
typedef CGAL::Unique_hash_map<Edge,int> UhmEdge2int; << this line is ok

list<Weighted_point> lwp;
Alpha_shape_3  as(lwp.begin(), lwp.end(), 0, Alpha_shape_3::GENERAL);

Alpha_shape_3::Finite_edges_iterator eit;
UhmEdge2int uhmedge2int;

for (eit = as.finite_edges_begin(); eit != as.finite_edges_end();eit++)
{
        if(as.classify(*eit,0)==Alpha_shape_3::REGULAR)
        {
                uhmedge2int[eit]=1; << there is an error with this line.  
error: no
match for ‘operator[]’ in ‘uhmedge2int[eit]’
        }
}

I also tried "uhmedge2int[*eit]" and it doesn't work.

But I thought I'm using it as the same way like in the example 51.4.2.

In example 51.4.2: "Example with edges marked as non-removable" a class
was build like this:

class Constrains_map : public boost::put_get_helper<bool,Constrains_map>
{
public:

  typedef boost::readable_property_map_tag                    category;
  typedef bool                                                value_type;
  typedef bool                                                reference;
  typedef boost::graph_traits<Surface const>::edge_descriptor key_type;

  Constrains_map() : mConstrains(false) {}

  reference operator[](key_type const& e) const { return e->is_border() || 
is_constrained(e) ; }
  
  void set_is_constrained ( key_type const& e, bool is )  { 
mConstrains[e]=is; }
  
  bool is_constrained( key_type const& e ) const { return 
mConstrains.is_defined(e) ? mConstrains[e] : false ; }
  
private:
  
  CGAL::Unique_hash_map<key_type,bool> mConstrains ;
  
};


Can anyone tell me what's wrong with my codes?

Best regards,

Lin

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Center of Computational and Systems Biology, 
Institute of Biophysics, CAS.
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