WSJT-X/boost/libs/iterator/example/indirect_iterator_example.cpp

60 lines
2.0 KiB
C++

// (C) Copyright Jeremy Siek 2000-2004.
// 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 <boost/config.hpp>
#include <vector>
#include <iostream>
#include <iterator>
#include <functional>
#include <algorithm>
#include <boost/iterator/indirect_iterator.hpp>
int main(int, char*[])
{
char characters[] = "abcdefg";
const int N = sizeof(characters)/sizeof(char) - 1; // -1 since characters has a null char
char* pointers_to_chars[N]; // at the end.
for (int i = 0; i < N; ++i)
pointers_to_chars[i] = &characters[i];
// Example of using indirect_iterator
boost::indirect_iterator<char**, char>
indirect_first(pointers_to_chars), indirect_last(pointers_to_chars + N);
std::copy(indirect_first, indirect_last, std::ostream_iterator<char>(std::cout, ","));
std::cout << std::endl;
// Example of making mutable and constant indirect iterators
char mutable_characters[N];
char* pointers_to_mutable_chars[N];
for (int j = 0; j < N; ++j)
pointers_to_mutable_chars[j] = &mutable_characters[j];
boost::indirect_iterator<char* const*> mutable_indirect_first(pointers_to_mutable_chars),
mutable_indirect_last(pointers_to_mutable_chars + N);
boost::indirect_iterator<char* const*, char const> const_indirect_first(pointers_to_chars),
const_indirect_last(pointers_to_chars + N);
std::transform(const_indirect_first, const_indirect_last,
mutable_indirect_first, std::bind1st(std::plus<char>(), 1));
std::copy(mutable_indirect_first, mutable_indirect_last,
std::ostream_iterator<char>(std::cout, ","));
std::cout << std::endl;
// Example of using make_indirect_iterator()
std::copy(boost::make_indirect_iterator(pointers_to_chars),
boost::make_indirect_iterator(pointers_to_chars + N),
std::ostream_iterator<char>(std::cout, ","));
std::cout << std::endl;
return 0;
}