So given this header. template < QSTYPE type, typename T, template <typename ELEM, typename = std::allocator<ELEM> > class CONT > CONT<T> quicksort(CONT<T>); // inside the main file. // I decided a function that takes vector of integer and returns a vector of integer. typedef boost::function<std::vector<int>(std::vector<int>)> sortfunc; // create a function list to hold the sorting function. // bunch of number include. #include <boost/assign/std/vector.hpp> std::vector<sortfunc> function_list; using boost::assign::operator+=; std::vector<sortfunc> function_list; // quicksort random function_list += (&algocpw::quicksort<algocpw::QSTYPE(algocpw::RANDOM), int, std::vector>), // quicksort median (&algocpw::quicksort<algocpw::QSTYPE(algocpw::MEDIAN), int, std::vector>), // quicksort mediantriple (&algocpw::quicksort<algocpw::QSTYPE(algocpw::MEDIANTRIPLE), int, std::vector>), // merge sort (&algocpw::mergesort<int, std::vector>), // heap sort (&algocpw::heapsort<int, std::vector>), // selection sort (&algocpw::selection_sort<int, std::vector>), // standard sort (&algocpw::standard_sort<int, std::vector>); I get the following errors. ./cs512/c++/sortingMain.cpp(63) : error C2896: 'boost::assign::list_inserter<boost::assign_detail::call_push_back<std::vector<_Ty,_Alloc>>,V> boost::assign::operator +=(std::vector<_Ty,_Alloc> &,V2)' : cannot use function template 'CONT<T> algocpw::mergesort(CONT<T>)' as a function argument c:\cpw\msvc\cs512\c++\def\../sortingAlgo.hpp(32) : see declaration of 'algocpw::mergesort' ./cs512/c++/sortingMain.cpp(63) : error C2784: 'boost::assign::list_inserter<boost::assign_detail::call_push_back<std::deque<T,Allocator>>,V> boost::assign::operator +=(std::deque<T,Allocator> &,V2)' : could not deduce template argument for 'std::deque<T,Allocator> &' from 'std::vector<_Ty>' with [ _Ty=sortfunc ] Where did "deque" come from.. i never included deque.