message: Better than vector, static_vector.
  Too lazy to change the others, there is way too much code shared between these utilities, we will have to factorize the code when moving it to a module.
diff: #include <boost/program_options.hpp>
  #include <boost/variant.hpp>
  +#include <boost/container/static_vector.hpp>
  #include <gudhi/Simplex_tree.h>
  #include <gudhi/Persistent_cohomology.h>
  @@ -65,7 +66,7 @@ using Cell_handle = Alpha_shape_3::Cell_handle;
  using Facet = Alpha_shape_3::Facet;
  using Edge_3 = Alpha_shape_3::Edge;
  using Vertex_handle = Alpha_shape_3::Vertex_handle;
  -using Vertex_list = std::vector<Alpha_shape_3::Vertex_handle>;
  +using Vertex_list = boost::container::static_vector<Alpha_shape_3::Vertex_handle, 4>;
  // gudhi type definition
  using ST = Gudhi::Simplex_tree<Gudhi::Simplex_tree_options_fast_persistence>;
  