c++ - Stl algorithms as function template -

i trying benchmark of stl algorithm on structures :

using namespace std;  template<typename a, typename t> void test(){     t c(1000);     a(c.begin(), c.end(), true);  } int main(){     test<find,vector<bool>>(); } 

but template argument deduction/substitution failed

everyone's answer good, let me add note.

to make code work without changing much.. has happen.

#include <vector> #include <algorithm>  template< typename searchfunctiontype, typename containertype > void test( searchfunctiontype fsearch, const containertype& container){     fsearch(container.begin(), container.end(), true); }  int main(){     std::vector<bool> v(1000);     test(std::find<std::vector<bool>::const_iterator, bool>, v); } 

std::find not type pointed out everyone. std::find function. may pass function pointer. look, std::find again template function, , compiler has no clue template argument std::find have. that's why don't pass std::find. instead ,

std::find<std::vector<bool>::const_iterator, bool>. 

edit:

#include <algorithm> #include <vector>   template < typename containertype          , typename containertype::const_iterator (*fpsearchfunction) (typename containertype::const_iterator, typename containertype::const_iterator, const typename containertype::value_type&) > void test(const containertype& c, const typename containertype::value_type& value) {     fpsearchfunction(c.begin(), c.end(), value); }   int main() {     std::vector<bool> v(1000);     test< std::vector<bool>, std::find<std::vector<bool>::const_iterator, bool> >(v, true); } 

this works on visualc. yes. integer type or function pointer can template argument too. bet there better way this.

edit 2:

although don't see why having templetized preferable hard coding, if make complication.

#include <vector> #include <algorithm> #include <chrono> #include <iostream> #include <cstdlib> #include <functional>  template <typename containertype> class benchmark { public:     typedef typename containertype::const_iterator  constiteratortype;     typedef typename containertype::value_type      valuetype;     typedef std::function < constiteratortype(constiteratortype, constiteratortype, const valuetype&) >         searchfunctiontype;     typedef std::chrono::high_resolution_clock      clocktype;      void testall(const containertype& container, const valuetype& serachval)     {         (std::size_t = 0; < m_functions.size(); ++i)         {                 clocktype::time_point begin = clocktype::now();             m_functions[i](container.begin(), container.end(), serachval);             clocktype::duration duration = clocktype::now() - begin;             std::cout << << " : " << duration.count() << std::endl;         }     }      void pushback(searchfunctiontype fsearch)     {         m_functions.push_back(fsearch);     } private:     std::vector<searchfunctiontype> m_functions; };  int main(){      typedef benchmark<std::vector<bool>> benchmarktype;     benchmarktype benchmark;     benchmark.pushback(std::find<benchmarktype::constiteratortype, benchmarktype::valuetype>);     benchmark.pushback([](benchmarktype::constiteratortype begin, benchmarktype::constiteratortype end, const benchmarktype::valuetype& v)     {         benchmarktype::constiteratortype iter;                 {             iter = begin + std::rand() % (end - begin);             if (*iter == v)                 return iter;         } while (iter != end);         return end;     });     struct binarysearch     {         benchmarktype::constiteratortype operator()(benchmarktype::constiteratortype begin, benchmarktype::constiteratortype end, const benchmarktype::valuetype& v)         {               return std::lower_bound(begin, end, v);         }     };     benchmark.pushback(binarysearch());      std::vector<bool> c;     c.assign(10000, false);     c.back() = true;      benchmark.testall(c, true);  } 

output:

0 : 100005 1 : 300017 2 : 0