blob: 2a27065feec57884d4f7d7b96fe9b7345f8cbbce [file] [log] [blame]
// (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
// (C) Copyright 2005-2007 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 implementations of get, read, put, write and seek which
// check a device's mode at runtime instead of compile time.
#ifndef NDNBOOST_IOSTREAMS_DETAIL_CHECKED_OPERATIONS_HPP_INCLUDED
#define NDNBOOST_IOSTREAMS_DETAIL_CHECKED_OPERATIONS_HPP_INCLUDED
#include <ndnboost/iostreams/categories.hpp>
#include <ndnboost/iostreams/detail/dispatch.hpp>
#include <ndnboost/iostreams/detail/error.hpp>
#include <ndnboost/iostreams/detail/config/unreachable_return.hpp>
#include <ndnboost/iostreams/get.hpp>
#include <ndnboost/iostreams/put.hpp>
#include <ndnboost/iostreams/read.hpp>
#include <ndnboost/iostreams/seek.hpp>
#include <ndnboost/iostreams/traits.hpp>
#include <ndnboost/iostreams/write.hpp>
#include <ndnboost/throw_exception.hpp>
// Must come last.
#include <ndnboost/iostreams/detail/config/disable_warnings.hpp> // MSVC.
namespace ndnboost { namespace iostreams {
namespace detail {
template<typename T>
struct read_write_if_impl;
template<typename T>
struct seek_if_impl;
} // End namespace detail.
template<typename T>
typename int_type_of<T>::type get_if(T& t)
{
typedef typename detail::dispatch<T, input, output>::type tag;
return detail::read_write_if_impl<tag>::get(t);
}
template<typename T>
inline std::streamsize
read_if(T& t, typename char_type_of<T>::type* s, std::streamsize n)
{
typedef typename detail::dispatch<T, input, output>::type tag;
return detail::read_write_if_impl<tag>::read(t, s, n);
}
template<typename T>
bool put_if(T& t, typename char_type_of<T>::type c)
{
typedef typename detail::dispatch<T, output, input>::type tag;
return detail::read_write_if_impl<tag>::put(t, c);
}
template<typename T>
inline std::streamsize write_if
(T& t, const typename char_type_of<T>::type* s, std::streamsize n)
{
typedef typename detail::dispatch<T, output, input>::type tag;
return detail::read_write_if_impl<tag>::write(t, s, n);
}
template<typename T>
inline std::streampos
seek_if( T& t, stream_offset off, NDNBOOST_IOS::seekdir way,
NDNBOOST_IOS::openmode which = NDNBOOST_IOS::in | NDNBOOST_IOS::out )
{
using namespace detail;
typedef typename dispatch<T, random_access, any_tag>::type tag;
return seek_if_impl<tag>::seek(t, off, way, which);
}
namespace detail {
//------------------Specializations of read_write_if_impl---------------------//
template<>
struct read_write_if_impl<input> {
template<typename T>
static typename int_type_of<T>::type get(T& t)
{ return iostreams::get(t); }
template<typename T>
static std::streamsize
read(T& t, typename char_type_of<T>::type* s, std::streamsize n)
{ return iostreams::read(t, s, n); }
template<typename T>
static bool put(T&, typename char_type_of<T>::type)
{ ndnboost::throw_exception(cant_write());
NDNBOOST_IOSTREAMS_UNREACHABLE_RETURN(false) }
template<typename T>
static std::streamsize
write(T&, const typename char_type_of<T>::type*, std::streamsize)
{ ndnboost::throw_exception(cant_write());
NDNBOOST_IOSTREAMS_UNREACHABLE_RETURN(0) }
};
template<>
struct read_write_if_impl<output> {
template<typename T>
static typename int_type_of<T>::type get(T&)
{ ndnboost::throw_exception(cant_read());
NDNBOOST_IOSTREAMS_UNREACHABLE_RETURN(0) }
template<typename T>
static std::streamsize
read(T&, typename char_type_of<T>::type*, std::streamsize)
{ ndnboost::throw_exception(cant_read());
NDNBOOST_IOSTREAMS_UNREACHABLE_RETURN(0) }
template<typename T>
static bool put(T& t, typename char_type_of<T>::type c)
{ return iostreams::put(t, c); }
template<typename T>
static std::streamsize
write( T& t, const typename char_type_of<T>::type* s,
std::streamsize n )
{ return iostreams::write(t, s, n); }
};
//------------------Specializations of seek_if_impl---------------------------//
template<>
struct seek_if_impl<random_access> {
template<typename T>
static std::streampos
seek( T& t, stream_offset off, NDNBOOST_IOS::seekdir way,
NDNBOOST_IOS::openmode which )
{ return iostreams::seek(t, off, way, which); }
};
template<>
struct seek_if_impl<any_tag> {
template<typename T>
static std::streampos
seek(T&, stream_offset, NDNBOOST_IOS::seekdir, NDNBOOST_IOS::openmode)
{ ndnboost::throw_exception(cant_seek());
NDNBOOST_IOSTREAMS_UNREACHABLE_RETURN(std::streampos()) }
};
} // End namespace detail.
} } // End namespaces iostreams, boost.
#include <ndnboost/iostreams/detail/config/enable_warnings.hpp> // MSVC.
#endif // #ifndef NDNBOOST_IOSTREAMS_DETAIL_CHECKED_OPERATIONS_HPP_INCLUDED