Hello, i have some questions: 1) Why min_element give me errors without BOOST_RANGE_ENABLE_CONCEPT_ASSERT defined 0? Is it uses only for make error messages more readable? Is it safe to define it to 0? #include <vector> //#define BOOST_RANGE_ENABLE_CONCEPT_ASSERT 0 #include <boost/range.hpp> #include <boost/range/adaptors.hpp> #include <boost/range/algorithm.hpp> #include <boost/range/numeric.hpp> #include <boost/bind.hpp> struct foo{ int x; }; int main() { using namespace boost::adaptors; using boost::bind; std::vector<foo> vec; auto rng = vec | transformed(bind(&foo::x, _1)); boost::accumulate(rng, 0); // ok boost::min_element(rng); // error } 2) Why only logical operators overloaded for boost::bind and arithmetic one are not? Is it safe to define it manually with BOOST_BIND_OPERATOR?