CGAL users discussion list

[Fernando Cacciola <>]

Hello Eivind,

> Speaking of Vertex_handle; am I the only one to mix up '.' and '->' with 
> Vertex_handle?
>
> [snip]
>
> Using '*' and '->' at the same time on a variable (which is not a 
> pointer type) looks "wrong" in my eyes
>
How about:

   std::list< Some_iterator > objects ;

Or in the upcoming version of C++

  std::list< std::shared_ptr<someobj> > objects ;

?

With those you also need '->' instead of '.'

> Can I generally assume that all types that end with "_handle" in CGAL 
> implements an "operator->"?
Yes.

Handles *refers* to other objects, just like iterators and pointers, so 
they provide indirect access via '->'

It is idiomatic to expect the left side of '->' to possibly refer to a 
non-existing object (say a past-the-end iterator or a null pointer), 
while that would be quite surprising for the left side of a '.'.

A default constructed handle, for instance, does not refer to any object 
at all:

void use_vertex ( Vertex_handle v )
{
  Vertex_handle null ;
  if ( v != null )
  {
    // 'v' corresponds to a valid vertex so go ahead and use it.
  }
}


HTH

Fernando Cacciola
GeometryFactory