examples/manual/multiset.cpp

/**************************************************************************
 *
 * multiset.cpp - Example program for multiset class.
 *
 * $Id: //stdlib/dev/examples/stdlib/manual/multiset.cpp#14 $
 *
 ***************************************************************************
 *
 * Copyright (c) 1994-2005 Quovadx,  Inc., acting through its  Rogue Wave
 * Software division. Licensed under the Apache License, Version 2.0 (the
 * "License");  you may  not use this file except  in compliance with the
 * License.    You    may   obtain   a   copy   of    the   License    at
 * http://www.apache.org/licenses/LICENSE-2.0.    Unless   required    by
 * applicable law  or agreed to  in writing,  software  distributed under
 * the License is distributed on an "AS IS" BASIS,  WITHOUT WARRANTIES OR
 * CONDITIONS OF  ANY KIND, either  express or implied.  See  the License
 * for the specific language governing permissions  and limitations under
 * the License.
 * 
 **************************************************************************/

#include <algorithm>   // for set_intersection(), set_union()
#include <iostream>    // for cout, endl, ostream
#include <iterator>    // for ostream_iterator
#include <sstream>     // for ostringstream
#include <set>         // for set

#include <examples.h>


typedef std::multiset<int, std::less<int>, std::allocator<int> > IntSet;


std::ostream& operator<< (std::ostream& out, const IntSet& s)
{
    std::ostringstream strm;

    typedef std::ostream_iterator<int, char, std::char_traits<char> >
        OstreamIter;

    std::copy (s.begin (), s.end (), OstreamIter (strm, " "));

    const std::ostream::sentry guard (out);

    if (guard) {
        const std::string data = strm.str ();

        if (   std::streamsize (data.size ())
            != out.rdbuf ()->sputn (data.data (), data.size ()))
            out.setstate (std::ios::badbit);
    }

    return out;
}


int main ()
{
    // Create a multiset of integers.
    IntSet  si;

    for (IntSet::value_type j = 0; j < 2; j++) {
        for (IntSet::value_type i = 0; i < 10; ++i)
            // Insert values with a hint.
            si.insert (si.begin (), i);
    }

    // Print out the multiset.
    std::cout << si << std::endl;

    // Make another multiset and an empty multiset.
    IntSet si2, result;
    for (IntSet::value_type i = 0; i < 10; i++)
        si2.insert (i + 5);

    std::cout << si2 << std::endl;

    // Try a couple of set algorithms.
    std::set_union (si.begin (), si.end (), si2.begin (), si2.end (),
                    std::inserter (result, result.begin ()));

    std::cout << "Union:\n" << result << std::endl;

    result.erase (result.begin (), result.end ());

    std::set_intersection (si.begin (), si.end (), si2.begin (), si2.end (),
                          std::inserter (result, result.begin ()));

    std::cout << "Intersection:\n" << result << std::endl;

    return 0;
}