Hi, Thanks Christopher for your commitment. Jeffrey Lee Hellrung, Jr. wrote:
SFINAE'ing out boost::fusion::begin/end for only Boost.Fusion sequences is only a partial solution, as it doesn't help for structures having both range and Boost.Fusion interfaces.
True. SFINAE'ing out is only a partial solution. Better solutions would be: A. (almost the same as Jeffrey's suggestion) If boost::fusion::begin/end doesn't need to be found via ADL, then use ADL barrier technique to fusion::begin/end (i.e. defining begin/end in another namespace and pull its name in namespace fusion by using directive/declaration). B. If boost::begin/end doesn't need to be found via ADL, then use ADL barrier technique to boost::begin/end. C. Define begin/end in namespace boost for all containers and ranges which live in namespace boost (boost::array, boost::iterator_range, boost::unordered_map, etc.). For example, define begin/end for boost::array in namespace boost. Since this is very tedious work, it would be better to define some BOOST_DEFINE_BEGIN_END macro for boilerplate code generation. Solutions B and C are, again, only a partial solution, since this only solves ambiguity call problems in namespace boost; the same thing can happen in another namespace. Solution A might break existing codes that relies on ADL to find boost::fusion::begin/end. Assuming any code in the Boost libraries does not rely on ADL for boost::fusion::begin/end, how about defining switch macro BOOST_FUSION_BEGIN_END_NO_ADL and making a user to choose whether A is applied or not? Regards, Michel