90 lines
2.9 KiB
C++
90 lines
2.9 KiB
C++
/**************************************************************************
|
|
*
|
|
* funct_ob.cpp - Example program for function objects.
|
|
*
|
|
* $Id: funct_ob.cpp 550991 2007-06-26 23:58:07Z sebor $
|
|
*
|
|
***************************************************************************
|
|
*
|
|
* 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>
|
|
#include <deque>
|
|
#include <functional>
|
|
#include <iostream>
|
|
#include <iterator>
|
|
#include <vector>
|
|
|
|
|
|
// Create a new function object from unary_function.
|
|
template <class Arg, class Result>
|
|
struct factorial: public std::unary_function<Arg, Result>
|
|
{
|
|
Result operator() (const Arg &arg) {
|
|
Result a = 1;
|
|
for (Arg i = 2; i <= arg; i++)
|
|
a *= i;
|
|
return a;
|
|
}
|
|
};
|
|
|
|
|
|
int main ()
|
|
{
|
|
// Typedefs for convenience.
|
|
typedef std::deque<int, std::allocator<int> > Deque;
|
|
typedef std::vector<long, std::allocator<long> > Vector;
|
|
|
|
// Initialize a deque with an array of integers.
|
|
Deque::value_type arr[] = { 1, 2, 3, 4, 5, 6, 7 };
|
|
Deque d (arr, arr + sizeof arr / sizeof *arr);
|
|
|
|
// Create an empty vector to store the factorials.
|
|
Vector v;
|
|
|
|
// Transform the numbers in the deque to their factorials
|
|
// and store in the vector.
|
|
std::transform (d.begin (), d.end (),
|
|
std::back_inserter (v),
|
|
factorial<Deque::value_type, Vector::value_type>());
|
|
|
|
// Create an iterator to output deque elements.
|
|
std::ostream_iterator<Deque::value_type,
|
|
char,
|
|
std::char_traits<char> > outd (std::cout, " ");
|
|
|
|
// Print the results.
|
|
std::cout << "The following numbers: \n ";
|
|
std::copy (d.begin (), d.end (), outd);
|
|
|
|
// Create an iterator to output vector elements.
|
|
std::ostream_iterator<Vector::value_type,
|
|
char,
|
|
std::char_traits<char> > outv (std::cout, " ");
|
|
|
|
std::cout << std::endl;
|
|
std::cout << "\nHave the factorials: \n ";
|
|
std::copy (v.begin (), v.end (), outv);
|
|
std::cout << std::endl;
|
|
|
|
return 0;
|
|
}
|