examples/manual/pnt2fnct.cpp

/**************************************************************************
 *
 * pnt2fnct.cpp - Example program of pointer to function.
 *
 * $Id$
 *
 ***************************************************************************
 *
 * Licensed to the Apache Software  Foundation (ASF) under one or more
 * contributor  license agreements.  See  the NOTICE  file distributed
 * with  this  work  for  additional information  regarding  copyright
 * ownership.   The ASF  licenses this  file to  you 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.
 *
 * Copyright 1994-2006 Rogue Wave Software.
 * 
 **************************************************************************/

#include <algorithm>    // for copy, transform
#include <functional>   // for ptr_fun
#include <iostream>     // cout, endl
#include <iterator>     // for ostream_iterator
#include <deque>        // for deque
#include <vector>       // for vector

#include <examples.h>


int factorial (int x)
{
    return x > 1 ? x * factorial (x - 1) : x;
}


int main ()
{
    typedef std::deque<int, std::allocator<int> >                     Deque;
    typedef std::vector<int, std::allocator<int> >                    Vector;
    typedef std::ostream_iterator<int, char, std::char_traits<char> > Iter;

    // Initialize a deque with an array of integers.
    const Deque::value_type a[] = { 1, 2, 3, 4, 5, 6, 7 };
    Deque d (a + 0, a + sizeof a / sizeof *a);

    // Create an empty vector to store the factorials.
    Vector v (Vector::size_type (7));

    // Compute factorials of the contents of `d' store results in `v'.
    std::transform (d.begin (), d.end (), v.begin (),
                    std::ptr_fun (factorial));

    // Print the results.
    std::cout << "The following numbers: \n     ";
    std::copy (d.begin (), d.end (), Iter (std::cout," "));

    std::cout << "\n\nHave the factorials: \n     ";
    std::copy (v.begin (), v.end (), Iter (std::cout, " "));
    std::cout << std::endl;

    return 0;
}