Chris@16: // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
Chris@16: // (C) Copyright 2005-2007 Jonathan Turkanis
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@16: // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
Chris@16: 
Chris@16: // See http://www.boost.org/libs/iostreams for documentation.
Chris@16: 
Chris@16: // Contains implementations of get, read, put, write and seek which
Chris@16: // check a device's mode at runtime instead of compile time.
Chris@16: 
Chris@16: #ifndef BOOST_IOSTREAMS_DETAIL_CHECKED_OPERATIONS_HPP_INCLUDED
Chris@16: #define BOOST_IOSTREAMS_DETAIL_CHECKED_OPERATIONS_HPP_INCLUDED
Chris@16: 
Chris@16: #include <boost/iostreams/categories.hpp>
Chris@16: #include <boost/iostreams/detail/dispatch.hpp>
Chris@16: #include <boost/iostreams/detail/error.hpp>
Chris@16: #include <boost/iostreams/detail/config/unreachable_return.hpp>
Chris@16: #include <boost/iostreams/get.hpp>
Chris@16: #include <boost/iostreams/put.hpp>
Chris@16: #include <boost/iostreams/read.hpp>
Chris@16: #include <boost/iostreams/seek.hpp>
Chris@16: #include <boost/iostreams/traits.hpp>
Chris@16: #include <boost/iostreams/write.hpp>
Chris@16: #include <boost/throw_exception.hpp>
Chris@16: 
Chris@16: // Must come last.
Chris@16: #include <boost/iostreams/detail/config/disable_warnings.hpp>  // MSVC.
Chris@16: 
Chris@16: namespace boost { namespace iostreams {
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: template<typename T> 
Chris@16: struct read_write_if_impl;
Chris@16: 
Chris@16: template<typename T> 
Chris@16: struct seek_if_impl;
Chris@16: 
Chris@16: } // End namespace detail.
Chris@16: 
Chris@16: template<typename T>
Chris@16: typename int_type_of<T>::type get_if(T& t)
Chris@16: { 
Chris@16:     typedef typename detail::dispatch<T, input, output>::type tag;
Chris@16:     return detail::read_write_if_impl<tag>::get(t);
Chris@16: }
Chris@16: 
Chris@16: template<typename T>
Chris@16: inline std::streamsize
Chris@16: read_if(T& t, typename char_type_of<T>::type* s, std::streamsize n)
Chris@16: { 
Chris@16:     typedef typename detail::dispatch<T, input, output>::type tag;
Chris@16:     return detail::read_write_if_impl<tag>::read(t, s, n);
Chris@16: }
Chris@16: 
Chris@16: template<typename T>
Chris@16: bool put_if(T& t, typename char_type_of<T>::type c)
Chris@16: { 
Chris@16:     typedef typename detail::dispatch<T, output, input>::type tag;
Chris@16:     return detail::read_write_if_impl<tag>::put(t, c);
Chris@16: }
Chris@16: 
Chris@16: template<typename T>
Chris@16: inline std::streamsize write_if
Chris@16:     (T& t, const typename char_type_of<T>::type* s, std::streamsize n)
Chris@16: { 
Chris@16:     typedef typename detail::dispatch<T, output, input>::type tag;
Chris@16:     return detail::read_write_if_impl<tag>::write(t, s, n);
Chris@16: }
Chris@16: 
Chris@16: template<typename T>
Chris@16: inline std::streampos
Chris@16: seek_if( T& t, stream_offset off, BOOST_IOS::seekdir way, 
Chris@16:          BOOST_IOS::openmode which = BOOST_IOS::in | BOOST_IOS::out )
Chris@16: { 
Chris@16:     using namespace detail;
Chris@16:     typedef typename dispatch<T, random_access, any_tag>::type tag;
Chris@16:     return seek_if_impl<tag>::seek(t, off, way, which);
Chris@16: }
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: //------------------Specializations of read_write_if_impl---------------------//
Chris@16: 
Chris@16: template<>
Chris@16: struct read_write_if_impl<input> {
Chris@16:     template<typename T>
Chris@16:     static typename int_type_of<T>::type get(T& t)
Chris@16:     { return iostreams::get(t); }
Chris@16: 
Chris@16:     template<typename T>
Chris@16:     static std::streamsize
Chris@16:     read(T& t, typename char_type_of<T>::type* s, std::streamsize n)
Chris@16:     { return iostreams::read(t, s, n); }
Chris@16: 
Chris@16:     template<typename T>
Chris@16:     static bool put(T&, typename char_type_of<T>::type)
Chris@16:     { boost::throw_exception(cant_write());
Chris@16:       BOOST_IOSTREAMS_UNREACHABLE_RETURN(false) }
Chris@16: 
Chris@16:     template<typename T>
Chris@16:     static std::streamsize 
Chris@16:     write(T&, const typename char_type_of<T>::type*, std::streamsize)
Chris@16:     { boost::throw_exception(cant_write());
Chris@16:       BOOST_IOSTREAMS_UNREACHABLE_RETURN(0) }
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct read_write_if_impl<output> {
Chris@16:     template<typename T>
Chris@16:     static typename int_type_of<T>::type get(T&)
Chris@16:     { boost::throw_exception(cant_read());
Chris@16:       BOOST_IOSTREAMS_UNREACHABLE_RETURN(0) }
Chris@16: 
Chris@16:     template<typename T>
Chris@16:     static std::streamsize
Chris@16:     read(T&, typename char_type_of<T>::type*, std::streamsize)
Chris@16:     { boost::throw_exception(cant_read());
Chris@16:       BOOST_IOSTREAMS_UNREACHABLE_RETURN(0) }
Chris@16: 
Chris@16:     template<typename T>
Chris@16:     static bool put(T& t, typename char_type_of<T>::type c)
Chris@16:     { return iostreams::put(t, c); }
Chris@16: 
Chris@16:     template<typename T>
Chris@16:     static std::streamsize 
Chris@16:     write( T& t, const typename char_type_of<T>::type* s, 
Chris@16:            std::streamsize n )
Chris@16:     { return iostreams::write(t, s, n); }
Chris@16: };
Chris@16: 
Chris@16: //------------------Specializations of seek_if_impl---------------------------//
Chris@16: 
Chris@16: template<>
Chris@16: struct seek_if_impl<random_access> {
Chris@16:     template<typename T>
Chris@16:     static std::streampos 
Chris@16:     seek( T& t, stream_offset off, BOOST_IOS::seekdir way, 
Chris@16:           BOOST_IOS::openmode which )
Chris@16:     { return iostreams::seek(t, off, way, which); }
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct seek_if_impl<any_tag> {
Chris@16:     template<typename T>
Chris@16:     static std::streampos 
Chris@16:     seek(T&, stream_offset, BOOST_IOS::seekdir, BOOST_IOS::openmode)
Chris@16:     { boost::throw_exception(cant_seek());
Chris@16:       BOOST_IOSTREAMS_UNREACHABLE_RETURN(std::streampos()) }
Chris@16: };
Chris@16: 
Chris@16: } // End namespace detail.
Chris@16: 
Chris@16: } } // End namespaces iostreams, boost.
Chris@16: 
Chris@16: #include <boost/iostreams/detail/config/enable_warnings.hpp>  // MSVC.
Chris@16: 
Chris@16: #endif // #ifndef BOOST_IOSTREAMS_DETAIL_CHECKED_OPERATIONS_HPP_INCLUDED