#include <map>
#include <vector>
#include <string>
#include <iostream>

int main() {
    std::multimap<std::pair<std::string, std::string>, std::vector<double>> mmList;
    std::vector<double> test = { 1.1, 2.2, 3.3 };

    mmList.emplace(std::make_pair("a", "b"), test);

    mmList.emplace(std::piecewise_construct,
        std::forward_as_tuple("a", "b"),
        std::forward_as_tuple(test));

    for (auto const& kv : mmList) {
        std::cout << "(" << kv.first.first << ", " << kv.first.second << ") =";
        for (auto const& d : kv.second) {
            std::cout << " " << d;
        }
        std::cout << std::endl;
    }

	return 0;
}