message: das.BoundMethod: Add pretty printer.
diff: #include <utility>
  +#include <elle/Printable.hh>
  #include <elle/attribute.hh>
  #include <elle/log.hh>
  @@ -9,6 +10,7 @@ namespace das
  {
  template <typename O, typename S>
  struct BoundMethod
  + : public elle::Printable::as<BoundMethod<O, S>>
  {
  BoundMethod(O& o)
  : _object(o)
  @@ -32,6 +34,12 @@ namespace das
  return S::method_call(this->_object, std::forward<Eff>(eff)...);
  }
  + void
  + print(std::ostream& o) const
  + {
  + elle::fprintf(o, "%s.%s", this->_object, S::name());
  + }
  +
  ELLE_ATTRIBUTE_R(O&, object);
  };
  