Squashed 'third_party/boostorg/iterator/' content from commit b2adecb
Change-Id: I284a73816f9cc846742923879275b84c6e0c915c
git-subtree-dir: third_party/boostorg/iterator
git-subtree-split: b2adecb951af025698618f19a3c838bd314966dc
diff --git a/example/permutation_iter_example.cpp b/example/permutation_iter_example.cpp
new file mode 100644
index 0000000..aad6125
--- /dev/null
+++ b/example/permutation_iter_example.cpp
@@ -0,0 +1,68 @@
+// Copyright (C) 2004 Jeremy Siek <jsiek@cs.indiana.edu>
+// 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)
+
+#include <iostream>
+#include <vector>
+#include <deque>
+#include <algorithm>
+#include <boost/iterator/permutation_iterator.hpp>
+#include <boost/cstdlib.hpp>
+#include <assert.h>
+
+
+int main() {
+ using namespace boost;
+ int i = 0;
+
+ typedef std::vector< int > element_range_type;
+ typedef std::deque< int > index_type;
+
+ static const int element_range_size = 10;
+ static const int index_size = 4;
+
+ element_range_type elements( element_range_size );
+ for(element_range_type::iterator el_it = elements.begin() ; el_it != elements.end() ; ++el_it)
+ *el_it = std::distance(elements.begin(), el_it);
+
+ index_type indices( index_size );
+ for(index_type::iterator i_it = indices.begin() ; i_it != indices.end() ; ++i_it )
+ *i_it = element_range_size - index_size + std::distance(indices.begin(), i_it);
+ std::reverse( indices.begin(), indices.end() );
+
+ typedef permutation_iterator< element_range_type::iterator, index_type::iterator > permutation_type;
+ permutation_type begin = make_permutation_iterator( elements.begin(), indices.begin() );
+ permutation_type it = begin;
+ permutation_type end = make_permutation_iterator( elements.begin(), indices.end() );
+
+ std::cout << "The original range is : ";
+ std::copy( elements.begin(), elements.end(), std::ostream_iterator< int >( std::cout, " " ) );
+ std::cout << "\n";
+
+ std::cout << "The reindexing scheme is : ";
+ std::copy( indices.begin(), indices.end(), std::ostream_iterator< int >( std::cout, " " ) );
+ std::cout << "\n";
+
+ std::cout << "The permutated range is : ";
+ std::copy( begin, end, std::ostream_iterator< int >( std::cout, " " ) );
+ std::cout << "\n";
+
+ std::cout << "Elements at even indices in the permutation : ";
+ it = begin;
+ for(i = 0; i < index_size / 2 ; ++i, it+=2 ) std::cout << *it << " ";
+ std::cout << "\n";
+
+ std::cout << "Permutation backwards : ";
+ it = begin + (index_size);
+ assert( it != begin );
+ for( ; it-- != begin ; ) std::cout << *it << " ";
+ std::cout << "\n";
+
+ std::cout << "Iterate backward with stride 2 : ";
+ it = begin + (index_size - 1);
+ for(i = 0 ; i < index_size / 2 ; ++i, it-=2 ) std::cout << *it << " ";
+ std::cout << "\n";
+
+ return boost::exit_success;
+}