ceph/src/boost/libs/iostreams/include/boost/iostreams/filter/stdio.hpp

   1 // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
   2 // (C) Copyright 2005-2007 Jonathan Turkanis
   3 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   4 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
   5
   6 // See http://www.boost.org/libs/iostreams for documentation.
   7
   8 // Based on the work of Christopher Diggins.
   9
  10 #ifndef BOOST_IOSTREAMS_STDIO_FILTER_HPP_INCLUDED
  11 #define BOOST_IOSTREAMS_STDIO_FILTER_HPP_INCLUDED
  12
  13 #if defined(_MSC_VER)
  14 # pragma once
  15 #endif
  16
  17 #include <iostream>
  18 #include <memory>    // allocator.
  19 #include <vector>
  20 #include <boost/iostreams/detail/config/wide_streams.hpp>
  21 #include <boost/iostreams/detail/char_traits.hpp>
  22 #include <boost/iostreams/detail/ios.hpp>
  23 #include <boost/iostreams/device/array.hpp>
  24 #include <boost/iostreams/device/back_inserter.hpp>
  25 #include <boost/iostreams/filter/aggregate.hpp>
  26 #include <boost/iostreams/pipeline.hpp>
  27 #include <boost/iostreams/stream_buffer.hpp>
  28
  29 namespace boost { namespace iostreams {
  30
  31 namespace detail {
  32
  33 } // End namespace detail.
  34
  35 template<typename Ch, typename Alloc = std::allocator<Ch> >
  36 class basic_stdio_filter : public aggregate_filter<Ch, Alloc> {
  37 private:
  38     typedef aggregate_filter<Ch, Alloc>       base_type;
  39 public:
  40     typedef typename base_type::char_type    char_type;
  41     typedef typename base_type::category     category;
  42     typedef typename base_type::vector_type  vector_type;
  43 private:
  44     static std::istream& standard_input(char*) { return std::cin; }
  45     static std::ostream& standard_output(char*) { return std::cout; }
  46 #ifndef BOOST_IOSTREAMS_NO_WIDE_STREAMS
  47     static std::wistream& standard_input(wchar_t*) { return std::wcin; }
  48     static std::wostream& standard_output(wchar_t*) { return std::wcout; }
  49 #endif // BOOST_IOSTREAMS_NO_WIDE_STREAMS
  50
  51     struct scoped_redirector { // Thanks to Maxim Egorushkin.
  52         typedef BOOST_IOSTREAMS_CHAR_TRAITS(Ch)                  traits_type;
  53         typedef BOOST_IOSTREAMS_BASIC_IOS(Ch, traits_type)       ios_type;
  54         typedef BOOST_IOSTREAMS_BASIC_STREAMBUF(Ch, traits_type) streambuf_type;
  55         scoped_redirector( ios_type& ios,
  56                            streambuf_type* newbuf )
  57             : ios_(ios), old_(ios.rdbuf(newbuf))
  58             { }
  59         ~scoped_redirector() { ios_.rdbuf(old_); }
  60         scoped_redirector& operator=(const scoped_redirector&);
  61         ios_type&        ios_;
  62         streambuf_type*  old_;
  63     };
  64
  65     virtual void do_filter() = 0;
  66     virtual void do_filter(const vector_type& src, vector_type& dest)
  67     {
  68         stream_buffer< basic_array_source<Ch> >
  69                           srcbuf(&src[0], &src[0] + src.size());
  70         stream_buffer< back_insert_device<vector_type> >
  71                           destbuf(iostreams::back_inserter(dest));
  72         scoped_redirector redirect_input(standard_input((Ch*)0), &srcbuf);
  73         scoped_redirector redirect_output(standard_output((Ch*)0), &destbuf);
  74         do_filter();
  75     }
  76 };
  77 BOOST_IOSTREAMS_PIPABLE(basic_stdio_filter, 2)
  78
  79 typedef basic_stdio_filter<char>     stdio_filter;
  80 typedef basic_stdio_filter<wchar_t>  wstdio_wfilter;
  81
  82 } } // End namespaces iostreams, boost.
  83
  84 #endif // #ifndef BOOST_IOSTREAMS_STDIO_FILTER_HPP_INCLUDED