Standard C++ Library Class Reference

OutputIterator result, Compare comp);
Description
The set_intersection algorithm constructs a sorted intersection of elements from the two ranges.
It returns the end of the constructed range. When it finds an element present in both ranges,
set_intersection always copies the element from the first range into result. This means that the
result of set_intersection is guaranteed to be stable. The result of set_intersection is undefined
if the result range overlaps with either of the original ranges.
set_intersection assumes that the ranges are sorted using the default comparision operator less
than (<), unless an alternative comparison operator (comp) is provided.
Complexity
At most ((last1 - first1) + (last2 - first2)) * 2 -1 comparisons are performed.
Example
//
// set_intr.cpp
//
#include <algorithm>
#include <set>
#include <iostream.h>
int main()
{
//Initialize some sets
int a1[10] = {1,3,5,7,9,11};
int a3[4] = {3,5,7,8};
set<int, less<int> > odd(a1, a1+6),
result, small(a3,a3+4);
//Create an insert_iterator for result
insert_iterator<set<int, less<int> > >
res_ins(result, result.begin());
//Demonstrate set_intersection
cout << "The result of:" << endl << "{";
copy(small.begin(),small.end(),
ostream_iterator<int>(cout," "));
cout << "} intersection {";
copy(odd.begin(),odd.end(),
ostream_iterator<int>(cout," "));
cout << "} =" << endl << "{";
set_intersection(small.begin(), small.end(),
odd.begin(), odd.end(), res_ins);