1. set<int> iset;
   iset.insert(...); 
   ....  // add several more values
   set<int>::iterator it = lower_bound(begin(iset), end(iset), value);

2. vector<int> ivect;
   ivect.reserve(...); // reserve memory for elements  
   ivect.push_back(...); 
   ....  // add several more values
   sort(begin(ivect), end(ivect));
   vector<int>::iterator it = lower_bound(begin(ivect), end(ivect), value);

3. set<int> iset;
   iset.insert(...); 
   ....  // add several more values
   set<int>::iterator it = iset.lower_bound(value);

4. unordered_set<int> iuset;
   iuset.insert(...); 
   ....  // add several more values
   sort(begin(iuset), end(iuset));
   unordered_set<int>::iterator it = lower_bound(begin(iuset), end(iuset), value);