iterator upper_bound ( const key_type& x ) const;

Return iterator to upper bound

Returns an iterator pointing to the first element in the container which compares greater than x (using the container's comparison object).

Unlike lower_bound, this member function does not return an iterator to the element if it compares equal to x, but only if it compares strictly greater.

Notice that, internally, all the elements in a set container are always ordered following the criterion defined by its comparison object, therefore all the elements that follow the one returned by this function will also compare greater than x.

Parameters

x

Key value to be compared.
key_type is a member type defined in set containers as an alias of Key, which is the first template parameter and the type of the elements stored in the container.

Return value

Example

// set::lower_bound/upper_bound
#include <iostream>
#include <set>
using namespace std;

int main ()
{
  set<int> myset;
  set<int>::iterator it,itlow,itup;

  for (int i=1; i<10; i++) myset.insert(i*10); // 10 20 30 40 50 60 70 80 90

  itlow=myset.lower_bound (30);                //       ^
  itup=myset.upper_bound (60);                 //                   ^

  myset.erase(itlow,itup);                     // 10 20 70 80 90

  cout << "myset contains:";
  for (it=myset.begin(); it!=myset.end(); it++)
    cout << " " << *it;
  cout << endl;

  return 0;
}

Notice that lower_bound(30) returns an iterator to 30, whereas upper_bound(60) returns an iterator to 70.

myset contains: 10 20 70 80 90

Complexity

See also