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 #include <vector> #include <fstream> #include <iterator> struct DirectoryEntry { }; std::istream &operator>>(std::istream &is, DirectoryEntry&) { return is; } template OutputIterator process (InputIterator, OutputIterator dest) { boost::function_requires

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