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@…