iostreams/device/array.hpp

0001 // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
0002 // (C) Copyright 2004-2007 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_ARRAY_HPP_INCLUDED
0009 #define BOOST_IOSTREAMS_ARRAY_HPP_INCLUDED
0010
0011 #if defined(_MSC_VER)
0012 # pragma once
0013 #endif
0014
0015 #include <boost/config.hpp>         // BOOST_MSVC, make sure size_t is in std.
0016 #include <boost/detail/workaround.hpp>
0017 #include <cstddef>                  // std::size_t.
0018 #include <utility>                  // pair.
0019 #include <boost/iostreams/categories.hpp>
0020 #include <boost/preprocessor/cat.hpp>
0021 #include <boost/static_assert.hpp>
0022 #include <boost/type_traits/is_convertible.hpp>
0023 #include <boost/type_traits/is_same.hpp>
0024
0025 namespace boost { namespace iostreams {
0026
0027 namespace detail {
0028
0029 template<typename Mode, typename Ch>
0030 class array_adapter {
0031 public:
0032     typedef Ch                                 char_type;
0033     typedef std::pair<char_type*, char_type*>  pair_type;
0034     struct category
0035         : public Mode,
0036           public device_tag,
0037           public direct_tag
0038         { };
0039     array_adapter(char_type* begin, char_type* end);
0040     array_adapter(char_type* begin, std::size_t length);
0041     array_adapter(const char_type* begin, const char_type* end);
0042     array_adapter(const char_type* begin, std::size_t length);
0043     template<int N>
0044     array_adapter(char_type (&ar)[N])
0045         : begin_(ar), end_(ar + N)
0046         { }
0047     pair_type input_sequence();
0048     pair_type output_sequence();
0049 private:
0050     char_type* begin_;
0051     char_type* end_;
0052 };
0053
0054 } // End namespace detail.
0055
0056 #define BOOST_IOSTREAMS_ARRAY(name, mode) \
0057     template<typename Ch> \
0058     struct BOOST_PP_CAT(basic_, name) : detail::array_adapter<mode, Ch> { \
0059     private: \
0060         typedef detail::array_adapter<mode, Ch>  base_type; \
0061     public: \
0062         typedef typename base_type::char_type    char_type; \
0063         typedef typename base_type::category     category; \
0064         BOOST_PP_CAT(basic_, name)(char_type* begin, char_type* end) \
0065             : base_type(begin, end) { } \
0066         BOOST_PP_CAT(basic_, name)(char_type* begin, std::size_t length) \
0067             : base_type(begin, length) { } \
0068         BOOST_PP_CAT(basic_, name)(const char_type* begin, const char_type* end) \
0069             : base_type(begin, end) { } \
0070         BOOST_PP_CAT(basic_, name)(const char_type* begin, std::size_t length) \
0071             : base_type(begin, length) { } \
0072         template<int N> \
0073         BOOST_PP_CAT(basic_, name)(Ch (&ar)[N]) \
0074             : base_type(ar) { } \
0075     }; \
0076     typedef BOOST_PP_CAT(basic_, name)<char>     name; \
0077     typedef BOOST_PP_CAT(basic_, name)<wchar_t>  BOOST_PP_CAT(w, name); \
0078     /**/
0079 BOOST_IOSTREAMS_ARRAY(array_source, input_seekable)
0080 BOOST_IOSTREAMS_ARRAY(array_sink, output_seekable)
0081 BOOST_IOSTREAMS_ARRAY(array, seekable)
0082 #undef BOOST_IOSTREAMS_ARRAY
0083
0084
0085 //------------------Implementation of array_adapter---------------------------//
0086
0087 namespace detail {
0088
0089 template<typename Mode, typename Ch>
0090 array_adapter<Mode, Ch>::array_adapter
0091     (char_type* begin, char_type* end)
0092     : begin_(begin), end_(end)
0093     { }
0094
0095 template<typename Mode, typename Ch>
0096 array_adapter<Mode, Ch>::array_adapter
0097     (char_type* begin, std::size_t length)
0098     : begin_(begin), end_(begin + length)
0099     { }
0100
0101 template<typename Mode, typename Ch>
0102 array_adapter<Mode, Ch>::array_adapter
0103     (const char_type* begin, const char_type* end)
0104     : begin_(const_cast<char_type*>(begin)),  // Treated as read-only.
0105       end_(const_cast<char_type*>(end))       // Treated as read-only.
0106 { BOOST_STATIC_ASSERT((!is_convertible<Mode, output>::value)); }
0107
0108 template<typename Mode, typename Ch>
0109 array_adapter<Mode, Ch>::array_adapter
0110     (const char_type* begin, std::size_t length)
0111     : begin_(const_cast<char_type*>(begin)),       // Treated as read-only.
0112       end_(const_cast<char_type*>(begin) + length) // Treated as read-only.
0113 { BOOST_STATIC_ASSERT((!is_convertible<Mode, output>::value)); }
0114
0115 template<typename Mode, typename Ch>
0116 typename array_adapter<Mode, Ch>::pair_type
0117 array_adapter<Mode, Ch>::input_sequence()
0118 { BOOST_STATIC_ASSERT((is_convertible<Mode, input>::value));
0119   return pair_type(begin_, end_); }
0120
0121 template<typename Mode, typename Ch>
0122 typename array_adapter<Mode, Ch>::pair_type
0123 array_adapter<Mode, Ch>::output_sequence()
0124 { BOOST_STATIC_ASSERT((is_convertible<Mode, output>::value));
0125   return pair_type(begin_, end_); }
0126
0127 } // End namespace detail.
0128
0129 //----------------------------------------------------------------------------//
0130
0131 } } // End namespaces iostreams, boost.
0132
0133 #endif // #ifndef BOOST_IOSTREAMS_ARRAY_HPP_INCLUDED