hi all, BOOST_IOSTREAMS_PIPABLE generate something like : template<..., typename component> pipeline<...> operator|(your_filter const& , component const&); It is proper for plan use, e.g. filter1 | filter2 | ... | device. But for boost::reference_wrapper, ref(filter1) | ref(filter2) |...|ref(device), after type conversion, will be : filter1 | ref(filter2) |...|ref(device), which may confuse the user. So, will it be a good idea to make another reloaded operator|(reference_wrapper<your_filter> const&, component const&)) ? I have written a macro to handle this( simply copy and modify BOOST_IOSTREAMS_PIPABLE): #define BOOST_IOSTREAMS_EXTENDED_PIPABLE(filter, arity) \ template< BOOST_PP_ENUM_PARAMS(arity, typename T) \ BOOST_PP_COMMA_IF(arity) typename Component> \ ::boost::iostreams::pipeline< \ ::boost::iostreams::detail::pipeline_segment<filter BOOST_IOSTREAMS_TEMPLATE_ARGS(arity, T)> \ ,Component \

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operator|(const filter BOOST_IOSTREAMS_TEMPLATE_ARGS(arity, T)& f, const Component& c) \ { \ typedef \ ::boost::iostreams::detail::pipeline_segment< \ filter BOOST_IOSTREAMS_TEMPLATE_ARGS(arity, T) \ > segment; \ return ::boost::iostreams::pipeline<segment, Component> \ (segment(f), c); \ } \ template<BOOST_PP_ENUM_PARAMS(arity, typename T) \ BOOST_PP_COMMA_IF(arity)typename Component> \ ::boost::iostreams::pipeline< \ ::boost::iostreams::detail::pipeline_segment< \ boost::reference_wrapper<filter BOOST_IOSTREAMS_TEMPLATE_ARGS(arity, T)> > \ ,Component \

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operator|(const boost::reference_wrapper<filter BOOST_IOSTREAMS_TEMPLATE_ARGS(arity, T)>& wf \ ,const Component& c) \ { \ typedef \ ::boost::iostreams::detail::pipeline_segment< \ boost::reference_wrapper<filter BOOST_IOSTREAMS_TEMPLATE_ARGS(arity, T)> \ > segment; \ return ::boost::iostreams::pipeline<segment, Component>(segment(wf), c); \ } \ /**/ -- View this message in context: http://old.nabble.com/-boost---iostreams--Pipelined-reference_wrappers-of-fi... Sent from the Boost - Users mailing list archive at Nabble.com.