c++ - partial sort a vector with lambda predicate -

i partial sort vector predicate such

std::vector<std::pair<std::string, int>> vp;          std::partial_sort(vp.begin(), vp.begin()+10, [](const std::pair<std::string,int> &left, const std::pair<std::string,int> &right)         {             return left.second > right.second;         }); 

however error

 no matching function call ‘partial_sort(std::vector<std::pair<std::basic_string<char>, int> >::iterator, __gnu_cxx::__normal_iterator<std::pair<std::basic_string<char>, int>*, .... 

the above works fine std::sort , not partial_sort suggestions ?

looking @ reference documentation, find std::partial_sort requires 3 iterators, not 2: start, middle , end. re-arrange range range [start, middle) sorted, , contains smallest elements range [start, end).

depending on you're trying achieve, need provide appropriate 3rd iterator. if you're trying find 10 smallest elements, this:

std::partial_sort(vp.begin(), vp.begin()+10, vp.end(), /*lambda before*/);