karma/stream/ostream_iterator.hpp

0001 //  Copyright (c) 2001-2011 Hartmut Kaiser
0002 //
0003 //  Distributed under the Boost Software License, Version 1.0. (See accompanying
0004 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0005
0006 #if !defined(BOOST_SPIRIT_KARMA_OSTREAM_ITERATOR_MAY_26_2007_1016PM)
0007 #define BOOST_SPIRIT_KARMA_OSTREAM_ITERATOR_MAY_26_2007_1016PM
0008
0009 #if defined(_MSC_VER)
0010 #pragma once
0011 #endif
0012
0013 #include <iosfwd>
0014 #include <iterator>
0015
0016 ///////////////////////////////////////////////////////////////////////////////
0017 namespace boost { namespace spirit { namespace karma
0018 {
0019     ///////////////////////////////////////////////////////////////////////////
0020     //  We need our own implementation of an ostream_iterator just to be able
0021     //  to access the wrapped ostream, which is necessary for the
0022     //  stream_generator, where we must generate the output using the original
0023     //  ostream to retain possibly registered facets.
0024     ///////////////////////////////////////////////////////////////////////////
0025     template <
0026         typename T, typename Elem = char
0027       , typename Traits = std::char_traits<Elem> >
0028     class ostream_iterator
0029     {
0030     public:
0031         typedef std::output_iterator_tag iterator_category;
0032         typedef void value_type;
0033         typedef void difference_type;
0034         typedef void pointer;
0035         typedef void reference;
0036         typedef Elem char_type;
0037         typedef Traits traits_type;
0038         typedef std::basic_ostream<Elem, Traits> ostream_type;
0039         typedef ostream_iterator<T, Elem, Traits> self_type;
0040
0041         ostream_iterator(ostream_type& os_, Elem const* delim_ = 0)
0042           : os(&os_), delim(delim_) {}
0043
0044         self_type& operator= (T const& val)
0045         {
0046             *os << val;
0047             if (0 != delim)
0048                 *os << delim;
0049             return *this;
0050         }
0051
0052         self_type& operator*() { return *this; }
0053         self_type& operator++() { return *this; }
0054         self_type operator++(int) { return *this; }
0055
0056         // expose underlying stream
0057         ostream_type& get_ostream() { return *os; }
0058         ostream_type const& get_ostream() const { return *os; }
0059
0060         // expose good bit of underlying stream object
0061         bool good() const { return get_ostream().good(); }
0062
0063     protected:
0064         ostream_type *os;
0065         Elem const* delim;
0066     };
0067
0068 }}}
0069
0070 #endif