#include <chrono>#include <cstddef>#include <functional>#include <iomanip>#include <iostream>#include <string>#include <set> class Dew{private:int a, b, c; public:    Dew(int _a,int _b,int _c): a(_a), b(_b), c(_c){} bool operator<(const Dew& other)const{return(a< other.a)||(a== other.a&& b< other.b)||(a== other.a&& b== other.b&& c< other.c);}}; constexprint nof_operations{101}; std::size_t set_emplace(){std::multiset<Dew> set;for(int i=0; i< nof_operations;++i)for(int j=0; j< nof_operations;++j)for(int k=0; k< nof_operations;++k)                set.emplace(i, j, k); return set.size();} std::size_t set_insert(){std::multiset<Dew> set;for(int i=0; i< nof_operations;++i)for(int j=0; j< nof_operations;++j)for(int k=0; k< nof_operations;++k)                set.insert(Dew(i, j, k)); return set.size();} void time_it(std::function<int()> set_test,std::string what=""){constauto start=std::chrono::system_clock::now();constauto the_size= set_test();constauto stop=std::chrono::system_clock::now();conststd::chrono::duration<double,std::milli> time= stop- start;if(!what.empty()&& the_size)std::cout<<std::fixed<<std::setprecision(2)<< time<<" for "<< what<<'\n';} int main(){    time_it(set_insert,"cache warming...");    time_it(set_insert,"insert");    time_it(set_insert,"insert");    time_it(set_emplace,"emplace");    time_it(set_emplace,"emplace");}

499.61ms for cache warming...447.89ms for insert436.77ms for insert430.62ms for emplace428.61ms for emplace