HPX_FORCEINLINE typename boost::enable_if< traits::is_future_or_future_range<Future> >::type operator()(boost::reference_wrapper<Future>& future) const { future.get() = Future(); }
inline typename sake::range_iterator<T>::type end(boost::reference_wrapper<T> x) { return sake::range::end(x.get()); }
// std::ostream output_stream(boost::reference_wrapper<std::ostream> os) : write_f(make_std_ostream_write_function(os.get())) {}
template <typename T> bool operator()(boost::reference_wrapper<T> a,boost::reference_wrapper<T> b) const { return a.get() == b.get(); }