What am I doing wrong?

Question

I've missed the boat on multiset. how would one insert 'char' key values for a multiset, rather than standard key values as index for value values...(key,value)

#include <iostream>
#include <vector>
#include <set>
#include <cstdlib>
#include <algorithm>
#include <iterator>

int main(){

std::vector<int> v(3200,rand()%100);

std::multiset<char,int> mset;
std::multiset<char,int>::iterator msetIt;

std::cout<<"copied vector v to multiset mset: "<<std::endl;

cpyVecToMSet(mset);

for(msetIt;msetIt != mset.end();msetIt++){
std::cout<<*msetIt<<" ";
};

return 0;
}

std::multiset<char,int> cpyVecToMSet(std::vector<int> &vect){

std::multiset<char, int> tmpMSet(vect.begin(),vect.end());

return tmpMSet;
};

Answer 1

I believe you are either looking for std::multimap, or trying to place std::pair within std::multiset. I've looked into the documentation of std::multiset - The declaration does not appear to allow you to map a key to a value. The second template argument is Compare, which tells the container how to sort the multiset. As a result, std::multiset<char, int> probably does not make sense.

You can try using

std::multiset<std::pair<char,int>> obj;
//obj.insert(std::make_pair('a', 1));
//obj.emplace('a', 1);

multiset<pair> example -> https://www.geeksforgeeks.org/multisetemplace-c-stl/

or

std::multimap<char,int> obj;

multimap ref -> http://www.cplusplus.com/reference/map/multimap/begin/

Answer 2

that completely answers my question. I have looked and looked for a way to make that work and this confirms I'll have to read more :)