Method cbegin

3rdParty/boost/boost/unordered/unordered_map.hpp:204–207

      const_iterator end() const BOOST_NOEXCEPT { return const_iterator(); }

      const_iterator cbegin() const BOOST_NOEXCEPT
      {
        return const_iterator(table_.begin());
      }

      const_iterator cend() const BOOST_NOEXCEPT { return const_iterator(); }