Function IsName

cpp/src/arrow/type.h:2146–2146

  bool IsFieldPath() const { return std::holds_alternative<FieldPath>(impl_); }
  bool IsName() const { return std::holds_alternative<std::string>(impl_); }
  bool IsNested() const {
    if (IsName()) return false;
    if (IsFieldPath()) return std::get<FieldPath>(impl_).indices().size() > 1;