1 // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com) 2 // (C) Copyright 2003-2007 Jonathan Turkanis 3 // Distributed under the Boost Software License, Version 1.0. (See accompanying 4 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.) 5 6 // See http://www.boost.org/libs/iostreams for documentation. 7 8 #ifndef BOOST_IOSTREAMS_OPTIMAL_BUFFER_SIZE_HPP_INCLUDED 9 #define BOOST_IOSTREAMS_OPTIMAL_BUFFER_SIZE_HPP_INCLUDED 10 11 #if defined(_MSC_VER) 12 # pragma once 13 #endif 14 15 #include <boost/config.hpp> // DEDUCED_TYPENAME, MSVC. 16 #include <boost/detail/workaround.hpp> 17 #include <boost/iostreams/constants.hpp> // constants. 18 #include <boost/iostreams/detail/dispatch.hpp> 19 #include <boost/iostreams/detail/wrap_unwrap.hpp> 20 #include <boost/iostreams/operations_fwd.hpp> 21 #include <boost/mpl/if.hpp> 22 23 // Must come last. 24 #include <boost/iostreams/detail/config/disable_warnings.hpp> 25 26 namespace boost { namespace iostreams { 27 28 namespace detail { 29 30 template<typename T> 31 struct optimal_buffer_size_impl; 32 33 } // End namespace detail. 34 35 template<typename T> optimal_buffer_size(const T & t)36std::streamsize optimal_buffer_size(const T& t) 37 { 38 typedef detail::optimal_buffer_size_impl<T> impl; 39 return impl::optimal_buffer_size(detail::unwrap(t)); 40 } 41 42 namespace detail { 43 44 //------------------Definition of optimal_buffer_size_impl--------------------// 45 46 template<typename T> 47 struct optimal_buffer_size_impl 48 : mpl::if_< 49 is_custom<T>, 50 operations<T>, 51 optimal_buffer_size_impl< 52 BOOST_DEDUCED_TYPENAME 53 dispatch< 54 T, optimally_buffered_tag, device_tag, filter_tag 55 >::type 56 > 57 >::type 58 { }; 59 60 template<> 61 struct optimal_buffer_size_impl<optimally_buffered_tag> { 62 template<typename T> optimal_buffer_sizeboost::iostreams::detail::optimal_buffer_size_impl63 static std::streamsize optimal_buffer_size(const T& t) 64 { return t.optimal_buffer_size(); } 65 }; 66 67 template<> 68 struct optimal_buffer_size_impl<device_tag> { 69 template<typename T> optimal_buffer_sizeboost::iostreams::detail::optimal_buffer_size_impl70 static std::streamsize optimal_buffer_size(const T&) 71 { return default_device_buffer_size; } 72 }; 73 74 template<> 75 struct optimal_buffer_size_impl<filter_tag> { 76 template<typename T> optimal_buffer_sizeboost::iostreams::detail::optimal_buffer_size_impl77 static std::streamsize optimal_buffer_size(const T&) 78 { return default_filter_buffer_size; } 79 }; 80 81 } // End namespace detail. 82 83 } } // End namespaces iostreams, boost. 84 85 #include <boost/iostreams/detail/config/enable_warnings.hpp> 86 87 #endif // #ifndef BOOST_IOSTREAMS_OPTIMAL_BUFFER_SIZE_HPP_INCLUDED 88