need STL set in insertion order

Question

How to store elements in set in insertion order. for example.

setmyset;

myset.insert(\"stack\");
myset.insert(\"overflow\");

Answer 1

If you can use Boost, a very straightforward solution is to use the header-only library Boost.Bimap (bidirectional maps).

Consider the following sample program that will display your dummy entries in insertion order (try out here):

#include 
#include 
#include 
#include 

using namespace std::string_literals;

template 
void insertCallOrdered(boost::bimap& mymap, const T& element) {
  // We use size() as index, therefore indexing with 0, 1, ... 
  // as we add elements to the bimap.
  mymap.insert({ element, mymap.size() });
}

int main() {
  boost::bimap mymap;

  insertCallOrdered(mymap, "stack"s);
  insertCallOrdered(mymap, "overflow"s);

  // Iterate over right map view (integers) in sorted order
  for (const auto& rit : mymap.right) {
    std::cout << rit.first << " -> " << rit.second << std::endl;
  }
}