Rutger ter Borg wrote:
I am experiencing a compiler error if I try to use a fusion join function on empty tuples. The operation I am trying to do does work with fusion::vectors. See attached; I guess this is a bug?
It's actually a boost::tuple bug. Here's the test: #include <boost/tuple/tuple.hpp> int main() { int const s = boost::tuples::length<boost::tuple<> const>::value; } The problem is that there is no specialization for const tuple<> and const null_type. I took the liberty to commit this obvious bug. I'll revert if there are objections. Here's the relevant code (tuple_basic.hpp): template<> struct length<tuple<> > { BOOST_STATIC_CONSTANT(int, value = 0); }; template<> struct length<tuple<> const> { BOOST_STATIC_CONSTANT(int, value = 0); }; template<> struct length<null_type> { BOOST_STATIC_CONSTANT(int, value = 0); }; template<> struct length<null_type const> { BOOST_STATIC_CONSTANT(int, value = 0); }; All tuple tests pass. Regards, -- Joel de Guzman http://www.boostpro.com http://spirit.sf.net