| .. Copyright David Abrahams 2006. Distributed under the Boost |
| .. Software License, Version 1.0. (See accompanying |
| .. file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| |
| Example |
| ....... |
| |
| This is a simple example of using the transform_iterators class to |
| generate iterators that multiply (or add to) the value returned by |
| dereferencing the iterator. It would be cooler to use lambda library |
| in this example. |
| |
| :: |
| |
| int x[] = { 1, 2, 3, 4, 5, 6, 7, 8 }; |
| const int N = sizeof(x)/sizeof(int); |
| |
| typedef boost::binder1st< std::multiplies<int> > Function; |
| typedef boost::transform_iterator<Function, int*> doubling_iterator; |
| |
| doubling_iterator i(x, boost::bind1st(std::multiplies<int>(), 2)), |
| i_end(x + N, boost::bind1st(std::multiplies<int>(), 2)); |
| |
| std::cout << "multiplying the array by 2:" << std::endl; |
| while (i != i_end) |
| std::cout << *i++ << " "; |
| std::cout << std::endl; |
| |
| std::cout << "adding 4 to each element in the array:" << std::endl; |
| std::copy(boost::make_transform_iterator(x, boost::bind1st(std::plus<int>(), 4)), |
| boost::make_transform_iterator(x + N, boost::bind1st(std::plus<int>(), 4)), |
| std::ostream_iterator<int>(std::cout, " ")); |
| std::cout << std::endl; |
| |
| |
| The output is:: |
| |
| multiplying the array by 2: |
| 2 4 6 8 10 12 14 16 |
| adding 4 to each element in the array: |
| 5 6 7 8 9 10 11 12 |
| |
| |
| The source code for this example can be found `here`__. |
| |
| __ ../example/transform_iterator_example.cpp |