message: Clarify doc about Squared_distance_d in Subsampling.
diff: @@ -53,9 +53,8 @@ enum : std::size_t {
  * The iteration starts with the landmark `starting point` or, if `starting point==random_starting_point`, with a random landmark.
  * \tparam Kernel must provide a type Kernel::Squared_distance_d which is a model of the
  * concept <a target="_blank"
  - * href="http://doc.cgal.org/latest/Kernel_d/classKernel__d_1_1Squared__distance__d.html">Kernel_d::Squared_distance_d</a>
  - * concept.
  - * It must also contain a public member 'squared_distance_d_object' of this type.
  + * href="http://doc.cgal.org/latest/Kernel_d/classKernel__d_1_1Squared__distance__d.html">Kernel_d::Squared_distance_d</a> (despite the name, taken from CGAL, this can be any kind of metric or proximity measure).
  + * It must also contain a public member `squared_distance_d_object()` that returns an object of this type.
  * \tparam Point_range Range whose value type is Kernel::Point_d. It must provide random-access
  * via `operator[]` and the points should be stored contiguously in memory.
  * \tparam PointOutputIterator Output iterator whose value type is Kernel::Point_d.
  