boost/iostreams/concepts.hpp

0001 // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
0002 // (C) Copyright 2003-2007 Jonathan Turkanis
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 // See http://www.boost.org/libs/iostreams for documentation.
0007
0008 #ifndef BOOST_IOSTREAMS_CONCEPTS_HPP_INCLUDED
0009 #define BOOST_IOSTREAMS_CONCEPTS_HPP_INCLUDED
0010
0011 #if defined(_MSC_VER)
0012 # pragma once
0013 #endif
0014
0015 #include <boost/config.hpp>  // BOOST_MSVC
0016 #include <boost/detail/workaround.hpp>
0017 #include <boost/iostreams/categories.hpp>
0018 #include <boost/iostreams/detail/default_arg.hpp>
0019 #include <boost/iostreams/detail/ios.hpp>  // openmode.
0020 #include <boost/iostreams/positioning.hpp>
0021 #include <boost/static_assert.hpp>
0022 #include <boost/type_traits/is_convertible.hpp>
0023
0024 namespace boost { namespace iostreams {
0025
0026 //--------------Definitions of helper templates for device concepts-----------//
0027
0028 template<typename Mode, typename Ch = char>
0029 struct device {
0030     typedef Ch char_type;
0031     struct category
0032         : Mode,
0033           device_tag,
0034           closable_tag,
0035           localizable_tag
0036         { };
0037
0038     void close()
0039     {
0040         using namespace detail;
0041         BOOST_STATIC_ASSERT((!is_convertible<Mode, two_sequence>::value));
0042     }
0043
0044     void close(BOOST_IOS::openmode)
0045     {
0046         using namespace detail;
0047         BOOST_STATIC_ASSERT((is_convertible<Mode, two_sequence>::value));
0048     }
0049
0050     template<typename Locale>
0051     void imbue(const Locale&) { }
0052 };
0053
0054 template<typename Mode, typename Ch = wchar_t>
0055 struct wdevice : device<Mode, Ch> { };
0056
0057 typedef device<input>    source;
0058 typedef wdevice<input>   wsource;
0059 typedef device<output>   sink;
0060 typedef wdevice<output>  wsink;
0061
0062 //--------------Definitions of helper templates for simple filter concepts----//
0063
0064 template<typename Mode, typename Ch = char>
0065 struct filter {
0066     typedef Ch char_type;
0067     struct category
0068         : Mode,
0069           filter_tag,
0070           closable_tag,
0071           localizable_tag
0072         { };
0073
0074     template<typename Device>
0075     void close(Device&)
0076     {
0077         using namespace detail;
0078         BOOST_STATIC_ASSERT((!is_convertible<Mode, two_sequence>::value));
0079         BOOST_STATIC_ASSERT((!is_convertible<Mode, dual_use>::value));
0080     }
0081
0082     template<typename Device>
0083     void close(Device&, BOOST_IOS::openmode)
0084     {
0085         using namespace detail;
0086         BOOST_STATIC_ASSERT(
0087             (is_convertible<Mode, two_sequence>::value) ||
0088             (is_convertible<Mode, dual_use>::value)
0089         );
0090     }
0091
0092     template<typename Locale>
0093     void imbue(const Locale&) { }
0094 };
0095
0096 template<typename Mode, typename Ch = wchar_t>
0097 struct wfilter : filter<Mode, Ch> { };
0098
0099 typedef filter<input>      input_filter;
0100 typedef wfilter<input>     input_wfilter;
0101 typedef filter<output>     output_filter;
0102 typedef wfilter<output>    output_wfilter;
0103 typedef filter<seekable>   seekable_filter;
0104 typedef wfilter<seekable>  seekable_wfilter;
0105 typedef filter<dual_use>   dual_use_filter;
0106 typedef wfilter<dual_use>  dual_use_wfilter;
0107
0108 //------Definitions of helper templates for multi-character filter cncepts----//
0109
0110 template<typename Mode, typename Ch = char>
0111 struct multichar_filter : filter<Mode, Ch> {
0112     struct category : filter<Mode, Ch>::category, multichar_tag { };
0113 };
0114
0115 template<typename Mode, typename Ch = wchar_t>
0116 struct multichar_wfilter : multichar_filter<Mode, Ch> { };
0117
0118 typedef multichar_filter<input>      multichar_input_filter;
0119 typedef multichar_wfilter<input>     multichar_input_wfilter;
0120 typedef multichar_filter<output>     multichar_output_filter;
0121 typedef multichar_wfilter<output>    multichar_output_wfilter;
0122 typedef multichar_filter<dual_use>   multichar_dual_use_filter;
0123 typedef multichar_wfilter<dual_use>  multichar_dual_use_wfilter;
0124
0125 //----------------------------------------------------------------------------//
0126
0127 } } // End namespaces iostreams, boost.
0128
0129 #endif // #ifndef BOOST_IOSTREAMS_CONCEPTS_HPP_INCLUDED