blob: 66abd9b86709e558808ab61dfaba288ebb9768b4 [file] [log] [blame]
Jeff Thompson86b6d642013-10-17 15:01:56 -07001// (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
2// (C) Copyright 2004-2007 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// Inspired by Daryle Walker's nullbuf from his More I/O submission.
9
10#ifndef NDNBOOST_IOSTREAMS_NULL_HPP_INCLUDED
11#define NDNBOOST_IOSTREAMS_NULL_HPP_INCLUDED
12
13#if defined(_MSC_VER) && (_MSC_VER >= 1020)
14# pragma once
15#endif
16
17#include <ndnboost/iostreams/categories.hpp>
18#include <ndnboost/iostreams/detail/ios.hpp> // openmode, streamsize.
19#include <ndnboost/iostreams/positioning.hpp>
20
21namespace ndnboost { namespace iostreams {
22
23template<typename Ch, typename Mode>
24class basic_null_device {
25public:
26 typedef Ch char_type;
27 struct category
28 : public Mode,
29 public device_tag,
30 public closable_tag
31 { };
32 std::streamsize read(Ch*, std::streamsize) { return 0; }
33 std::streamsize write(const Ch*, std::streamsize n) { return n; }
34 std::streampos seek( stream_offset, NDNBOOST_IOS::seekdir,
35 NDNBOOST_IOS::openmode =
36 NDNBOOST_IOS::in | NDNBOOST_IOS::out )
37 { return -1; }
38 void close() { }
39 void close(NDNBOOST_IOS::openmode) { }
40};
41
42template<typename Ch>
43struct basic_null_source : private basic_null_device<Ch, input> {
44 typedef Ch char_type;
45 typedef source_tag category;
46 using basic_null_device<Ch, input>::read;
47 using basic_null_device<Ch, input>::close;
48};
49
50typedef basic_null_source<char> null_source;
51typedef basic_null_source<wchar_t> wnull_source;
52
53template<typename Ch>
54struct basic_null_sink : private basic_null_device<Ch, output> {
55 typedef Ch char_type;
56 typedef sink_tag category;
57 using basic_null_device<Ch, output>::write;
58 using basic_null_device<Ch, output>::close;
59};
60
61typedef basic_null_sink<char> null_sink;
62typedef basic_null_sink<wchar_t> wnull_sink;
63
64} } // End namespaces iostreams, boost.
65
66#endif // #ifndef NDNBOOST_IOSTREAMS_NULL_HPP_INCLUDED