ATL / WTL / STL

// Attempt the insertion
std::pair<iterator, bool> insertionResult = map.insert(std::make_pair(key, value));
// If the value was alredy there, just update it...
if (!insertionResult.second) insertionResult.first->second = value;

#pragma warning(disable:4786)
#include <map>
 
using namespace std;
 
template <class map_type>
map_type::iterator insert_if_not_present(map_type& m,const map_type::value_type& v)
{
  map_type::iterator it=m.lower_bound(v.first);
  if(it!=m.end()){
    if(!m.key_comp()(v.first,it->first)){ // already present
      return it;
    }
  }
  if(it!=m.begin())--it; // set the insertion point
  return m.insert(it,v);
}
 
int main(void)
{
  map<int,int> m;
 
  insert_if_not_present(m,make_pair(1,1));
  insert_if_not_present(m,make_pair(2,2));
  insert_if_not_present(m,make_pair(3,3));
  insert_if_not_present(m,make_pair(2,2));
 
  return 0;
}

#pragma warning(disable:4786)
#include <queue>
#include <string>
#include <algorithm>
 
typedef std::deque<std::pair<std::string,int> > deqStringInt;
 
struct my_search
{
  my_search(const std::string s):s(s){}
  bool operator()(const std::pair<std::string,int>& c) const
  {
    return c.first==s;
  }
private:
  std::string s;
};
 
int main(void)
{
  deqStringInt example;
  example.push_back(std::make_pair(std::string("December"), 21));
 
  std::find_if(example.begin(),example.end(),my_search("December"));
 
  return 0;
}

ostringstream out;

int   n = 1;
short s = 2;

out << n << ' ' << s;

// send the string over the network ( out.str () )

istringstream in ( out.str () );

n = s = 0;

in >> n >> s;

cout << "n = " << n << ", s = " << s << endl;