// (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 BOOST_IOSTREAMS_DETAIL_CHECKED_OPERATIONS_HPP_INCLUDED | |
#define BOOST_IOSTREAMS_DETAIL_CHECKED_OPERATIONS_HPP_INCLUDED | |
#include <boost/iostreams/categories.hpp> | |
#include <boost/iostreams/detail/dispatch.hpp> | |
#include <boost/iostreams/detail/error.hpp> | |
#include <boost/iostreams/detail/config/unreachable_return.hpp> | |
#include <boost/iostreams/get.hpp> | |
#include <boost/iostreams/put.hpp> | |
#include <boost/iostreams/read.hpp> | |
#include <boost/iostreams/seek.hpp> | |
#include <boost/iostreams/traits.hpp> | |
#include <boost/iostreams/write.hpp> | |
#include <boost/throw_exception.hpp> | |
// Must come last. | |
#include <boost/iostreams/detail/config/disable_warnings.hpp> // MSVC. | |
namespace boost { 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, BOOST_IOS::seekdir way, | |
BOOST_IOS::openmode which = BOOST_IOS::in | BOOST_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) | |
{ boost::throw_exception(cant_write()); | |
BOOST_IOSTREAMS_UNREACHABLE_RETURN(false) } | |
template<typename T> | |
static std::streamsize | |
write(T&, const typename char_type_of<T>::type*, std::streamsize) | |
{ boost::throw_exception(cant_write()); | |
BOOST_IOSTREAMS_UNREACHABLE_RETURN(0) } | |
}; | |
template<> | |
struct read_write_if_impl<output> { | |
template<typename T> | |
static typename int_type_of<T>::type get(T&) | |
{ boost::throw_exception(cant_read()); | |
BOOST_IOSTREAMS_UNREACHABLE_RETURN(0) } | |
template<typename T> | |
static std::streamsize | |
read(T&, typename char_type_of<T>::type*, std::streamsize) | |
{ boost::throw_exception(cant_read()); | |
BOOST_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, BOOST_IOS::seekdir way, | |
BOOST_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, BOOST_IOS::seekdir, BOOST_IOS::openmode) | |
{ boost::throw_exception(cant_seek()); | |
BOOST_IOSTREAMS_UNREACHABLE_RETURN(std::streampos()) } | |
}; | |
} // End namespace detail. | |
} } // End namespaces iostreams, boost. | |
#include <boost/iostreams/detail/config/enable_warnings.hpp> // MSVC. | |
#endif // #ifndef BOOST_IOSTREAMS_DETAIL_CHECKED_OPERATIONS_HPP_INCLUDED |