Function SafeCallIntoPython

python/pyarrow/src/arrow/python/common.h:152–165

// The GIL is acquired, and the current thread's error status is preserved.
template <typename Function>
auto SafeCallIntoPython(Function&& func) -> decltype(func()) {
  PyAcquireGIL lock;
  PyObject* exc_type;
  PyObject* exc_value;
  PyObject* exc_traceback;
  PyErr_Fetch(&exc_type, &exc_value, &exc_traceback);
  auto maybe_status = std::forward<Function>(func)();
  // If the return Status is a "Python error", the current Python error status
  // describes the error and shouldn't be clobbered.
  if (!IsPyError(::arrow::ToStatus(maybe_status)) && exc_type != NULLPTR) {
    PyErr_Restore(exc_type, exc_value, exc_traceback);
  }
  return maybe_status;
}

template <typename Function>
auto SafeCallIntoPythonVoid(Function&& func) -> decltype(func()) {