[Boost-users] How can I use boost::lambda bind libray in a template

I have a function which takes a map (with int as key) and put all keys into another vector: void keySet2(map<int, string> aMap, vector<int>& keySet) { transform( aMap.begin(), aMap.end(), back_inserter(keySet), bind(&map<int, string>::value_type::first, _1) ); } But when I turn that find function into a template, I have compile erro. So is it possible to use boost in a template? here is my code: template <class T> void keySet(T& aMap, vector<int>& keySet) { transform( aMap.begin(), aMap.end(), back_inserter(keySet), bind(&T::value_type::first, _1) ); } here is the error: g++ -O0 -g3 -Wall -c -fmessage-length=0 -oBlockGrouper.o ../BlockGrouper.cpp ../Utils.h: In function ‘void keySet(T&, std::vector<int, std::allocator<int> >&)’: ../Utils.h:149: error: ‘_1’ was not declared in this scope __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com