message: Finally figure out the magic mysteries of pybind.
diff: @@ -22,7 +22,8 @@ void layer_bind(py::module &m) {
  .def_property_readonly("voxel_size", &TsdfLayer::voxel_size)
  .def_property_readonly("voxels_per_side", &TsdfLayer::voxels_per_side)
  - .def("saveToFile", (bool (TsdfLayer::*)(const std::string&)) &TsdfLayer::saveToFile)
  + .def("saveToFile", (bool (TsdfLayer::*)(const std::string &) const) &
  + TsdfLayer::saveToFile)
  .def("allocateBlockPtrByCoordinates",
  &TsdfLayer::allocateBlockPtrByCoordinates)
  @@ -35,8 +36,8 @@ void layer_bind(py::module &m) {
  .def_property_readonly("voxel_size", &EsdfLayer::voxel_size)
  .def_property_readonly("voxels_per_side", &EsdfLayer::voxels_per_side)
  - .def("saveToFile", &EsdfLayer::saveToFile)
  -
  + .def("saveToFile", (bool (EsdfLayer::*)(const std::string &) const) &
  + EsdfLayer::saveToFile)
  .def("allocateBlockPtrByCoordinates",
  &EsdfLayer::allocateBlockPtrByCoordinates)
  .def("removeBlockByCoordinates", &EsdfLayer::removeBlockByCoordinates);
  