message: Use boundary_opposite_vertex_simplex_range instead of boundary_simplex_range in alpha
diff: @@ -464,7 +464,8 @@ class Alpha_complex {
  using Vertex_handle = typename SimplicialComplexForAlpha::Vertex_handle;
  // ### Foreach Tau face of Sigma
  - for (auto f_boundary : complex.boundary_simplex_range(f_simplex)) {
  + for (auto face_opposite_vertex : complex.boundary_opposite_vertex_simplex_range(f_simplex)) {
  + auto f_boundary = face_opposite_vertex.first;
  #ifdef DEBUG_TRACES
  std::clog << " | --------------------------------------------------\n";
  std::clog << " | Tau ";
  @@ -485,16 +486,8 @@ class Alpha_complex {
  #endif // DEBUG_TRACES
  // ### Else
  } else {
  - // Find which vertex of f_simplex is missing in f_boundary. We could actually write a variant of boundary_simplex_range that gives pairs (f_boundary, vertex). We rely on the fact that simplex_vertex_range is sorted.
  - auto longlist = complex.simplex_vertex_range(f_simplex);
  - auto shortlist = complex.simplex_vertex_range(f_boundary);
  - auto longiter = std::begin(longlist);
  - auto shortiter = std::begin(shortlist);
  - auto enditer = std::end(shortlist);
  - while(shortiter != enditer && *longiter == *shortiter) { ++longiter; ++shortiter; }
  - Vertex_handle extra = *longiter;
  auto const& cache=get_cache(complex, f_boundary);
  - bool is_gab = kernel_.is_gabriel(cache, get_point_(extra));
  + bool is_gab = kernel_.is_gabriel(cache, get_point_(face_opposite_vertex.second));
  #ifdef DEBUG_TRACES
  std::clog << " | Tau is_gabriel(Sigma)=" << is_gab << " - vertexForGabriel=" << extra << std::endl;
  #endif // DEBUG_TRACES
  