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Editing: checked_operations.hpp
// (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
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