Hi, I am looking into the documentation of hana to merge two or more maps, say: #include <boost/hana.hpp> namespace hana = boost::hana; int main(int argc, char **argv) { constexpr auto m1 = hana::make_map( hana::make_pair("key1"_s, hana::type_c<std::string>), hana::make_pair("key2"_s, hana::type_c<std::string>) ); constexpr auto m2 = hana::make_map( hana::make_pair("key3"_s, hana::type_c<std::string>), hana::make_pair("key4"_s, hana::type_c<std::string>), hana::make_pair("key5"_s, hana::type_c<std::string>) ); // Merge two or more maps? constexpr auto result = m1 + m2; return 0; } I'm not sure how to do this, probably taking the first map and for every pair in the subsequent map return an insert? In pseudo code: constexpr result = hana::insert(hana::insert(m1, pair1), pair2); Can someone give me some pointers in the right direction? Regards, Matthijs