I'm compiling at Warning Level 4, using VC.NET 2003, and Boost 1.32.0. Is there something I can do to eliminate these warnings, or should I just suppress them? Am I using the concept checking functions improperly? Thanks for any help! -------------------------------- John Wismar john.wismar@autozone.com -------------------------------------------------------------------------------------------------- Here's some very stripped-down code: #include <boost/concept_check.hpp> #include <vector> #include <fstream> #include <iterator> struct DirectoryEntry { }; std::istream &operator>>(std::istream &is, DirectoryEntry&) { return is; } template <typename InputIterator, typename OutputIterator> OutputIterator process (InputIterator, OutputIterator dest) { boost::function_requires<boost::InputIteratorConcept<InputIterator>

(); boost::function_requires<boost::OutputIteratorConcept<OutputIterator, typename std::iterator_traits<InputIterator>:: value_type> >(); return dest; }

int main(int, char*[]) { std::ifstream input; std::vector<DirectoryEntry> directoryVector; process(std::istream_iterator<DirectoryEntry>(input), std:: back_inserter(directoryVector)); return 0; } This generates the following warnings: Compiling... concepttest.cpp c:\boost\boost\concept_check.hpp(573) : warning C4510: 'boost::OutputIteratorConcept<TT,ValueT>' : default constructor could not be generated with [ TT=std::back_insert_iterator<std::vector<DirectoryEntry>>, ValueT=std::iterator_traits<std::istream_iterator<DirectoryEntry>>::value_type ] c:\boost\boost\concept_check.hpp(48) : see reference to class template instantiation 'boost::OutputIteratorConcept<TT,ValueT>' being compiled with [ TT=std::back_insert_iterator<std::vector<DirectoryEntry>>, ValueT=std::iterator_traits<std::istream_iterator<DirectoryEntry>>::value_type ] c:\Temp\concepttest\concepttest.cpp(16) : see reference to function template instantiation 'void boost::function_requires<boost::OutputIteratorConcept<TT,ValueT>>(boost::mpl::identity<T> *)' being compiled with [ TT=std::back_insert_iterator<std::vector<DirectoryEntry>>, ValueT=std::iterator_traits<std::istream_iterator<DirectoryEntry>>::value_type, T=boost::OutputIteratorConcept<std::back_insert_iterator<std::vector<DirectoryEntry>>,std::iterator_traits<std::istream_iterator<DirectoryEntry>>::value_type> ] c:\Temp\concepttest\concepttest.cpp(24) : see reference to function template instantiation 'OutputIterator process<std::istream_iterator<_Ty>,std::back_insert_iterator<_Container>>(InputIterator,OutputIterator)' being compiled with [ OutputIterator=std::back_insert_iterator<std::vector<DirectoryEntry>>, _Ty=DirectoryEntry, _Container=std::vector<DirectoryEntry>, InputIterator=std::istream_iterator<DirectoryEntry> ] c:\boost\boost\concept_check.hpp(573) : warning C4610: struct 'boost::OutputIteratorConcept<TT,ValueT>' can never be instantiated - user defined constructor required with [ TT=std::back_insert_iterator<std::vector<DirectoryEntry>>, ValueT=std::iterator_traits<std::istream_iterator<DirectoryEntry>>::value_type ] c:\boost\boost\concept_check.hpp(234) : warning C4510: 'boost::AssignableConcept<TT>' : default constructor could not be generated with [ TT=std::back_insert_iterator<std::vector<DirectoryEntry>> ] c:\boost\boost\concept_check.hpp(48) : see reference to class template instantiation 'boost::AssignableConcept<TT>' being compiled with [ TT=std::back_insert_iterator<std::vector<DirectoryEntry>> ] c:\boost\boost\concept_check.hpp(566) : see reference to function template instantiation 'void boost::function_requires<boost::AssignableConcept<TT>>(boost::mpl::identity<T> *)' being compiled with [ TT=std::back_insert_iterator<std::vector<DirectoryEntry>>, T=boost::AssignableConcept<std::back_insert_iterator<std::vector<DirectoryEntry>>> ] c:\boost\boost\concept_check.hpp(565) : while compiling class-template member function 'void boost::OutputIteratorConcept<TT,ValueT>::constraints(void)' with [ TT=std::back_insert_iterator<std::vector<DirectoryEntry>>, ValueT=std::iterator_traits<std::istream_iterator<DirectoryEntry>>::value_type ] c:\boost\boost\concept_check.hpp(48) : see reference to class template instantiation 'boost::OutputIteratorConcept<TT,ValueT>' being compiled with [ TT=std::back_insert_iterator<std::vector<DirectoryEntry>>, ValueT=std::iterator_traits<std::istream_iterator<DirectoryEntry>>::value_type ] c:\Temp\concepttest\concepttest.cpp(16) : see reference to function template instantiation 'void boost::function_requires<boost::OutputIteratorConcept<TT,ValueT>>(boost::mpl::identity<T> *)' being compiled with [ TT=std::back_insert_iterator<std::vector<DirectoryEntry>>, ValueT=std::iterator_traits<std::istream_iterator<DirectoryEntry>>::value_type, T=boost::OutputIteratorConcept<std::back_insert_iterator<std::vector<DirectoryEntry>>,std::iterator_traits<std::istream_iterator<DirectoryEntry>>::value_type> ] c:\boost\boost\concept_check.hpp(234) : warning C4610: struct 'boost::AssignableConcept<TT>' can never be instantiated - user defined constructor required with [ TT=std::back_insert_iterator<std::vector<DirectoryEntry>> ]