Other compilers may not require it, but it is in accordance with the ANSI standard. I don't know where it talks about it in the standard, but you can look in Stroustrup's "The C++ Programming Language" 3rd edition, Appendix C, section 13.5. He gives a good explanation why this is necessary. Perhaps someone else on the list can actually explain why this is so, if you don't have access to a good C++ reference. Thanks, Lyle -----Original Message----- From: gcc-help-owner@xxxxxxxxxxx [mailto:gcc-help-owner@xxxxxxxxxxx] On Behalf Of Darko Miletic Sent: Tuesday, September 14, 2004 12:20 PM To: gcc help Subject: template issue I have been playing with std::for_each and std::map and came with interresting issue: //main.cpp #include <iostream> #include <algorithm> #include <string> #include <map> typedef std::map<int, std::string> mapType; template <typename M> inline void printMapValue(const M& value) { std::cout << value.first << " - " << value.second << "\n"; } template <typename T > void print_map(const T& map_) { std::for_each( map_.begin(), map_.end(), printMapValue<typename T::value_type>); // if typename is removed here GCC reports error??? std::cout << std::endl; } int main(int argc, char* argv[]) { mapType map_; map_[0] = "111"; map_[1] = "222"; map_[2] = "333"; print_map<mapType>(map_); return 0; } If I remove keyword typename from print_map function GCC reports this: error: no matching function for call to `for_each( std::_Rb_tree_iterator<std::pair<const int, std::string>, const std::pair<const int, std::string>&, const std::pair<const int, std::string>*>, std::_Rb_tree_iterator<std::pair<const int, std::string>, const std::pair<const int, std::string>&, const std::pair<const int, std::string>*>, <unknown type>)' Why is typename needed here? Other compilers like BCB 5&6 and MSVC 7.1 compile this fine without typename keyword. Darko
