typename Func,
typename = typename std::enable_if<std::is_convertible<
typename std::result_of<Func()>::type,
- const typename Map::mapped_type&>::value>::type>
+ const typename Map::mapped_type&>::value>::type,
+ typename = typename std::enable_if<
+ std::is_reference<typename std::result_of<Func()>::type>::value>::type>
const typename Map::mapped_type& get_ref_default(
const Map& map,
const typename Map::key_type& key,