id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
8418,Boost Fusion foreach works for std::tuple OR boost::tuple depending on inclusion order,bugs@…,Joel de Guzman,"As my attached repro sample shows can't adapt std::tuple and boost::tuple at the same time.

The headers

{{{
#   include <boost/fusion/adapted/boost_tuple.hpp>
#   include <boost/fusion/adapted/std_tuple.hpp>
}}}

seem to mutually exclude each other (at least in this code sample). Which ever header of the two gets included _first_, determines which type of tuple will be usable as a fusion sequence in that TU.

In the case of the 'blanket' include `boost/fusion/adapted.hpp` this means that std::tuple is not usable as a Fusion Sequence - unless one explicitely include `boost/fusion/adapted/std_tuple.hpp` _ahead_ of that.

This is rather surprising, and obviously causes problems for people mixing std::tuple and boost::tuple within a sinlge TU. 

Also, although I haven't looked too deeply into the mechanics of it, I worry a bit that this may be a signal that '''ODR violations''' could be lurking when different TUs include the headers in different order.",Bugs,closed,To Be Determined,fusion,Boost 1.53.0,Problem,fixed,fusion tuple adapted,bugs@… william@…