// (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
// (C) Copyright 2003-2007 Jonathan Turkanis
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
// See http://www.boost.org/libs/iostreams for documentation.
//
// Contains metafunctions char_type_of, category_of and mode_of used for
// deducing the i/o category and i/o mode of a model of Filter or Device.
//
// Also contains several utility metafunctions, functions and macros.
//
#ifndef BOOST_IOSTREAMS_IO_TRAITS_HPP_INCLUDED
#define BOOST_IOSTREAMS_IO_TRAITS_HPP_INCLUDED
#if defined(_MSC_VER) && (_MSC_VER >= 1020)
# pragma once
#endif
#include <iosfwd> // stream types, char_traits.
#include <boost/config.hpp> // partial spec, deduced typename.
#include <boost/detail/workaround.hpp>
#include <boost/iostreams/categories.hpp>
#include <boost/iostreams/detail/bool_trait_def.hpp>
#include <boost/iostreams/detail/config/wide_streams.hpp>
#include <boost/iostreams/detail/is_iterator_range.hpp>
#include <boost/iostreams/detail/select.hpp>
#include <boost/iostreams/detail/select_by_size.hpp>
#include <boost/iostreams/detail/wrap_unwrap.hpp>
#include <boost/iostreams/traits_fwd.hpp>
#include <boost/mpl/bool.hpp>
#include <boost/mpl/eval_if.hpp>
#include <boost/mpl/identity.hpp>
#include <boost/mpl/int.hpp>
#include <boost/mpl/or.hpp>
#if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
# include <boost/range/iterator_range.hpp>
# include <boost/range/value_type.hpp>
#endif // #if BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
#include <boost/ref.hpp>
#include <boost/type_traits/is_convertible.hpp>
// Must come last.
#include <boost/iostreams/detail/config/disable_warnings.hpp>
namespace boost { namespace iostreams {
//----------Definitions of predicates for streams and stream buffers----------//
#ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //--------------------------------//
BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_istream, std::basic_istream, 2)
BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_ostream, std::basic_ostream, 2)
BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_iostream, std::basic_iostream, 2)
BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_streambuf, std::basic_streambuf, 2)
BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_ifstream, std::basic_ifstream, 2)
BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_ofstream, std::basic_ofstream, 2)
BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_fstream, std::basic_fstream, 2)
BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_filebuf, std::basic_filebuf, 2)
BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_istringstream, std::basic_istringstream, 3)
BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_ostringstream, std::basic_ostringstream, 3)
BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_stringstream, std::basic_stringstream, 3)
BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_stringbuf, std::basic_stringbuf, 3)
#else // #ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //-----------------------//
BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_istream, std::istream, 0)
BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_ostream, std::ostream, 0)
BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_iostream, std::iostream, 0)
BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_streambuf, std::streambuf, 0)
#endif // #ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //----------------------//
template<typename T>
struct is_std_io
: mpl::or_< is_istream<T>, is_ostream<T>, is_streambuf<T> >
{ };
template<typename T>
struct is_std_file_device
: mpl::or_<
is_ifstream<T>,
is_ofstream<T>,
is_fstream<T>,
is_filebuf<T>
>
{ };
template<typename T>
struct is_std_string_device
: mpl::or_<
is_istringstream<T>,
is_ostringstream<T>,
is_stringstream<T>,
is_stringbuf<T>
>
{ };
template<typename Device, typename Tr, typename Alloc>
struct stream;
template<typename T, typename Tr, typename Alloc, typename Mode>
class stream_buffer;
template< typename Mode, typename Ch, typename Tr,
typename Alloc, typename Access >
class filtering_stream;
template< typename Mode, typename Ch, typename Tr,
typename Alloc, typename Access >
class wfiltering_stream;
template< typename Mode, typename Ch, typename Tr,
typename Alloc, typename Access >
class filtering_streambuf;
template< typename Mode, typename Ch, typename Tr,
typename Alloc, typename Access >
class filtering_wstreambuf;
namespace detail {
template<typename T, typename Tr>
class linked_streambuf;
BOOST_IOSTREAMS_BOOL_TRAIT_DEF( is_boost_stream,
boost::iostreams::stream,
3 )
BOOST_IOSTREAMS_BOOL_TRAIT_DEF( is_boost_stream_buffer,
boost::iostreams::stream_buffer,
4 )
BOOST_IOSTREAMS_BOOL_TRAIT_DEF( is_filtering_stream_impl,
boost::iostreams::filtering_stream,
5 )
BOOST_IOSTREAMS_BOOL_TRAIT_DEF( is_filtering_wstream_impl,
boost::iostreams::wfiltering_stream,
5 )
BOOST_IOSTREAMS_BOOL_TRAIT_DEF( is_filtering_streambuf_impl,
boost::iostreams::filtering_streambuf,
5 )
BOOST_IOSTREAMS_BOOL_TRAIT_DEF( is_filtering_wstreambuf_impl,
boost::iostreams::filtering_wstreambuf,
5 )
BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_linked, linked_streambuf, 2)
template<typename T>
struct is_filtering_stream
: mpl::or_<
is_filtering_stream_impl<T>,
is_filtering_wstream_impl<T>
>
{ };
template<typename T>
struct is_filtering_streambuf
: mpl::or_<
is_filtering_streambuf_impl<T>,
is_filtering_wstreambuf_impl<T>
>
{ };
template<typename T>
struct is_boost
: mpl::or_<
is_boost_stream<T>,
is_boost_stream_buffer<T>,
is_filtering_stream<T>,
is_filtering_streambuf<T>
>
{ };
} // End namespace detail.
//------------------Definitions of char_type_of-------------------------------//
namespace detail {
template<typename T>
struct member_char_type { typedef typename T::char_type type; };
} // End namespace detail.
#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION //---------------------------//
# ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //-------------------------------//
template<typename T>
struct char_type_of
: detail::member_char_type<
typename detail::unwrapped_type<T>::type
>
{ };
# else // # ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //---------------------//
template<typename T>
struct char_type_of {
typedef typename detail::unwrapped_type<T>::type U;
typedef typename
mpl::eval_if<
is_std_io<U>,
mpl::identity<char>,
detail::member_char_type<U>
>::type type;
};
# endif // # ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //--------------------//
template<typename Iter>
struct char_type_of< iterator_range<Iter> > {
typedef typename iterator_value<Iter>::type type;
};
#else // #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION //------------------//
template<typename T>
struct char_type_of {
template<typename U>
struct get_value_type {
#if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
typedef typename range_value<U>::type type;
#endif // #if BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
};
typedef typename
mpl::eval_if<
is_iterator_range<T>,
get_value_type<T>,
detail::member_char_type<
BOOST_DEDUCED_TYPENAME detail::unwrapped_type<T>::type
>
>::type type;
};
#endif // #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION //-----------------//
//------------------Definitions of category_of--------------------------------//
namespace detail {
template<typename T>
struct member_category { typedef typename T::category type; };
} // End namespace detail.
template<typename T>
struct category_of {
template<typename U>
struct member_category {
typedef typename U::category type;
};
typedef typename detail::unwrapped_type<T>::type U;
typedef typename
mpl::eval_if<
mpl::and_<
is_std_io<U>,
mpl::not_< detail::is_boost<U> >
>,
iostreams::select< // Disambiguation for Tru64
is_filebuf<U>, filebuf_tag,
is_ifstream<U>, ifstream_tag,
is_ofstream<U>, ofstream_tag,
is_fstream<U>, fstream_tag,
is_stringbuf<U>, stringbuf_tag,
is_istringstream<U>, istringstream_tag,
is_ostringstream<U>, ostringstream_tag,
is_stringstream<U>, stringstream_tag,
is_streambuf<U>, generic_streambuf_tag,
is_iostream<U>, generic_iostream_tag,
is_istream<U>, generic_istream_tag,
is_ostream<U>, generic_ostream_tag
>,
detail::member_category<U>
>::type type;
};
// Partial specialization for reference wrappers
#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION //---------------------------//
template<typename T>
struct category_of< reference_wrapper<T> >
: category_of<T>
{ };
#endif // #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION //-----------------//
//------------------Definition of get_category--------------------------------//
//
// Returns an object of type category_of<T>::type.
//
template<typename T>
inline typename category_of<T>::type get_category(const T&)
{ typedef typename category_of<T>::type category; return category(); }
//------------------Definition of int_type_of---------------------------------//
template<typename T>
struct int_type_of {
#ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES
typedef std::char_traits<
BOOST_DEDUCED_TYPENAME char_type_of<T>::type
> traits_type;
typedef typename traits_type::int_type type;
#else
typedef int type;
#endif
};
//------------------Definition of mode_of-------------------------------------//
namespace detail {
template<int N> struct io_mode_impl;
#define BOOST_IOSTREAMS_MODE_HELPER(tag_, id_) \
case_<id_> io_mode_impl_helper(tag_); \
template<> struct io_mode_impl<id_> { typedef tag_ type; }; \
/**/
BOOST_IOSTREAMS_MODE_HELPER(input, 1)
BOOST_IOSTREAMS_MODE_HELPER(output, 2)
BOOST_IOSTREAMS_MODE_HELPER(bidirectional, 3)
BOOST_IOSTREAMS_MODE_HELPER(input_seekable, 4)
BOOST_IOSTREAMS_MODE_HELPER(output_seekable, 5)
BOOST_IOSTREAMS_MODE_HELPER(seekable, 6)
BOOST_IOSTREAMS_MODE_HELPER(dual_seekable, 7)
BOOST_IOSTREAMS_MODE_HELPER(bidirectional_seekable, 8)
BOOST_IOSTREAMS_MODE_HELPER(dual_use, 9)
#undef BOOST_IOSTREAMS_MODE_HELPER
template<typename T>
struct io_mode_id {
typedef typename category_of<T>::type category;
BOOST_SELECT_BY_SIZE(int, value, detail::io_mode_impl_helper(category()));
};
} // End namespace detail.
template<typename T> // Borland 5.6.4 requires this circumlocution.
struct mode_of : detail::io_mode_impl< detail::io_mode_id<T>::value > { };
// Partial specialization for reference wrappers
#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION //---------------------------//
template<typename T>
struct mode_of< reference_wrapper<T> >
: mode_of<T>
{ };
#endif // #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION //-----------------//
//------------------Definition of is_device, is_filter and is_direct----------//
namespace detail {
template<typename T, typename Tag>
struct has_trait_impl {
typedef typename category_of<T>::type category;
BOOST_STATIC_CONSTANT(bool, value = (is_convertible<category, Tag>::value));
};
template<typename T, typename Tag>
struct has_trait
: mpl::bool_<has_trait_impl<T, Tag>::value>
{ };
} // End namespace detail.
template<typename T>
struct is_device : detail::has_trait<T, device_tag> { };
template<typename T>
struct is_filter : detail::has_trait<T, filter_tag> { };
template<typename T>
struct is_direct : detail::has_trait<T, direct_tag> { };
//------------------Definition of BOOST_IOSTREAMS_STREAMBUF_TYPEDEFS----------//
#define BOOST_IOSTREAMS_STREAMBUF_TYPEDEFS(Tr) \
typedef Tr traits_type; \
typedef typename traits_type::int_type int_type; \
typedef typename traits_type::off_type off_type; \
typedef typename traits_type::pos_type pos_type; \
/**/
} } // End namespaces iostreams, boost.
#include <boost/iostreams/detail/config/enable_warnings.hpp>
#endif // #ifndef BOOST_IOSTREAMS_IO_TRAITS_HPP_INCLUDED