I’m currently on Boost 1.56 so this might have been fixed by now, but in a simple test Boost.Coroutine fails to properly model the InputIterator concept, because *it++ does not conform to the operational semantics { T tmp = *it; ++it; return tmp; } required by the standard. The failing program: #include <boost/coroutine/asymmetric_coroutine.hpp> #include <iostream> template<typename Continuation> auto foo(Continuation && yield) -> void { yield("Hello"); yield(", "); yield("World"); yield("!\n"); } //using T = char const *; using T = std::string; auto foo() -> boost::coroutines::asymmetric_coroutine<T>::pull_type { using namespace boost::coroutines; return asymmetric_coroutine<T>::pull_type{ [](asymmetric_coroutine<T>::push_type& yield) { foo(yield); } }; } auto main(int, char **) -> int { auto f = foo(); for(auto it = boost::begin(f); it != boost::end(f);) std::cout << *it++; } Which (on my machine) outputs: , World! X☺à r2 ` , ` , Ç2 Ç Failing to model the InputIterator concept is bad, because then it isn’t any kind of standards-conforming iterator at all. Interestingly, if T is char const * and not std::string the program works as expected. Is there some other subtle bug at work here? -- Johannes S. Mueller-Roemer, MSc Wiss. Mitarbeiter - Interactive Engineering Technologies (IET) Fraunhofer-Institut für Graphische Datenverarbeitung IGD Fraunhoferstr. 5 | 64283 Darmstadt | Germany Tel +49 6151 155-606 | Fax +49 6151 155-139 johannes.mueller-roemer@igd.fraunhofer.de | www.igd.fraunhofer.de