boost/typeof/msvc/typeof_impl.hpp
// Copyright (C) 2005 Igor Chesnokov, mailto:ichesnokov@gmail.com (VC 6.5,VC 7.1 + counter code) // Copyright (C) 2005-2007 Peder Holt (VC 7.0 + framework) // Copyright (C) 2006 Steven Watanabe (VC 8.0) // Use, modification and distribution is subject to the Boost Software // License, Version 1.0. (http://www.boost.org/LICENSE_1_0.txt) #ifndef BOOST_TYPEOF_MSVC_TYPEOF_IMPL_HPP_INCLUDED # define BOOST_TYPEOF_MSVC_TYPEOF_IMPL_HPP_INCLUDED # include <boost/config.hpp> # include <boost/detail/workaround.hpp> # include <boost/mpl/int.hpp> # include <boost/type_traits/is_function.hpp> # include <boost/utility/enable_if.hpp> # if BOOST_WORKAROUND(BOOST_MSVC,>=1310) # include <typeinfo> # endif namespace boost { namespace type_of { //Compile time constant code # if BOOST_WORKAROUND(BOOST_MSVC,>=1300) && defined(_MSC_EXTENSIONS) template<int N> struct the_counter; template<typename T,int N = 5/*for similarity*/> struct encode_counter { __if_exists(the_counter<N + 256>) { BOOST_STATIC_CONSTANT(unsigned,count=(encode_counter<T,N + 257>::count)); } __if_not_exists(the_counter<N + 256>) { __if_exists(the_counter<N + 64>) { BOOST_STATIC_CONSTANT(unsigned,count=(encode_counter<T,N + 65>::count)); } __if_not_exists(the_counter<N + 64>) { __if_exists(the_counter<N + 16>) { BOOST_STATIC_CONSTANT(unsigned,count=(encode_counter<T,N + 17>::count)); } __if_not_exists(the_counter<N + 16>) { __if_exists(the_counter<N + 4>) { BOOST_STATIC_CONSTANT(unsigned,count=(encode_counter<T,N + 5>::count)); } __if_not_exists(the_counter<N + 4>) { __if_exists(the_counter<N>) { BOOST_STATIC_CONSTANT(unsigned,count=(encode_counter<T,N + 1>::count)); } __if_not_exists(the_counter<N>) { BOOST_STATIC_CONSTANT(unsigned,count=N); typedef the_counter<N> type; } } } } } }; # define BOOST_TYPEOF_INDEX(T) (encode_counter<T>::count) # define BOOST_TYPEOF_NEXT_INDEX(next) # else template<int N> struct encode_counter : encode_counter<N - 1> {}; template<> struct encode_counter<0> {}; //Need to default to a larger value than 4, as due to MSVC's ETI errors. (sizeof(int)==4) char (*encode_index(...))[5]; # define BOOST_TYPEOF_INDEX(T) (sizeof(*boost::type_of::encode_index((boost::type_of::encode_counter<1005>*)0))) # define BOOST_TYPEOF_NEXT_INDEX(next) friend char (*encode_index(encode_counter<next>*))[next]; # endif //Typeof code # if BOOST_WORKAROUND(BOOST_MSVC,==1300) template<typename ID> struct msvc_extract_type { template<bool> struct id2type_impl; typedef id2type_impl<true> id2type; }; template<typename T, typename ID> struct msvc_register_type : msvc_extract_type<ID> { template<> struct id2type_impl<true> //VC7.0 specific bugfeature { typedef T type; }; }; #elif BOOST_WORKAROUND(BOOST_MSVC,>=1400) struct msvc_extract_type_default_param {}; template<typename ID, typename T = msvc_extract_type_default_param> struct msvc_extract_type; template<typename ID> struct msvc_extract_type<ID, msvc_extract_type_default_param> { template<bool> struct id2type_impl; typedef id2type_impl<true> id2type; }; template<typename ID, typename T> struct msvc_extract_type : msvc_extract_type<ID,msvc_extract_type_default_param> { template<> struct id2type_impl<true> //VC8.0 specific bugfeature { typedef T type; }; template<bool> struct id2type_impl; typedef id2type_impl<true> id2type; }; template<typename T, typename ID> struct msvc_register_type : msvc_extract_type<ID, T> { }; # else template<typename ID> struct msvc_extract_type { struct id2type; }; template<typename T, typename ID> struct msvc_register_type : msvc_extract_type<ID> { typedef msvc_extract_type<ID> base_type; struct base_type::id2type // This uses nice VC6.5 and VC7.1 bugfeature { typedef T type; }; }; # endif // EAN: preprocess this block out on advice of Peder Holt // to eliminate errors in type_traits/common_type.hpp # if 0 //BOOST_WORKAROUND(BOOST_MSVC,==1310) template<const std::type_info& ref_type_info> struct msvc_typeid_wrapper { typedef typename msvc_extract_type<msvc_typeid_wrapper>::id2type id2type; typedef typename id2type::type wrapped_type; typedef typename wrapped_type::type type; }; //This class is used for registering the type T. encode_type<T> is mapped against typeid(encode_type<T>). //msvc_typeid_wrapper<typeid(encode_type<T>)> will now have a type typedef that equals encode_type<T>. template<typename T> struct encode_type { typedef encode_type<T> input_type; //Invoke registration of encode_type<T>. typeid(encode_type<T>) is now mapped to encode_type<T>. Do not use registered_type for anything. //The reason for registering encode_type<T> rather than T, is that VC handles typeid(function reference) poorly. By adding another //level of indirection, we solve this problem. typedef typename msvc_register_type<input_type,msvc_typeid_wrapper<typeid(input_type)> >::id2type registered_type; typedef T type; }; template<typename T> typename disable_if< typename is_function<T>::type, typename encode_type<T>::input_type>::type encode_start(T const&); template<typename T> typename enable_if< typename is_function<T>::type, typename encode_type<T>::input_type>::type encode_start(T&); template<typename Organizer, typename T> msvc_register_type<T,Organizer> typeof_register_type(const T&); # define BOOST_TYPEOF(expr) \ boost::type_of::msvc_typeid_wrapper<typeid(boost::type_of::encode_start(expr))>::type # define BOOST_TYPEOF_TPL(expr) typename BOOST_TYPEOF(expr) # define BOOST_TYPEOF_NESTED_TYPEDEF_TPL(name,expr) \ struct name {\ enum {_typeof_register_value=sizeof(typeid(boost::type_of::typeof_register_type<name>(expr)))};\ typedef typename boost::type_of::msvc_extract_type<name>::id2type id2type;\ typedef typename id2type::type type;\ }; # define BOOST_TYPEOF_NESTED_TYPEDEF(name,expr) \ struct name {\ enum {_typeof_register_value=sizeof(typeid(boost::type_of::typeof_register_type<name>(expr)))};\ typedef boost::type_of::msvc_extract_type<name>::id2type id2type;\ typedef id2type::type type;\ }; # else template<int ID> struct msvc_typeid_wrapper { typedef typename msvc_extract_type<mpl::int_<ID> >::id2type id2type; typedef typename id2type::type type; }; //Workaround for ETI-bug for VC6 and VC7 template<> struct msvc_typeid_wrapper<1> { typedef msvc_typeid_wrapper<1> type; }; //Workaround for ETI-bug for VC7.1 template<> struct msvc_typeid_wrapper<4> { typedef msvc_typeid_wrapper<4> type; }; //Tie it all together template<typename T> struct encode_type { //Get the next available compile time constants index BOOST_STATIC_CONSTANT(unsigned,value=BOOST_TYPEOF_INDEX(T)); //Instantiate the template typedef typename msvc_register_type<T,mpl::int_<value> >::id2type type; //Set the next compile time constants index BOOST_STATIC_CONSTANT(unsigned,next=value+1); //Increment the compile time constant (only needed when extensions are not active BOOST_TYPEOF_NEXT_INDEX(next); }; template<class T> struct sizer { typedef char(*type)[encode_type<T>::value]; }; # if BOOST_WORKAROUND(BOOST_MSVC,>=1310) template<typename T> typename disable_if< typename is_function<T>::type, typename sizer<T>::type>::type encode_start(T const&); template<typename T> typename enable_if< typename is_function<T>::type, typename sizer<T>::type>::type encode_start(T&); # else template<typename T> typename sizer<T>::type encode_start(T const&); # endif template<typename Organizer, typename T> msvc_register_type<T,Organizer> typeof_register_type(const T&,Organizer* =0); # define BOOST_TYPEOF(expr) \ boost::type_of::msvc_typeid_wrapper<sizeof(*boost::type_of::encode_start(expr))>::type # define BOOST_TYPEOF_TPL(expr) typename BOOST_TYPEOF(expr) # define BOOST_TYPEOF_NESTED_TYPEDEF_TPL(name,expr) \ struct name {\ BOOST_STATIC_CONSTANT(int,_typeof_register_value=sizeof(boost::type_of::typeof_register_type<name>(expr)));\ typedef typename boost::type_of::msvc_extract_type<name>::id2type id2type;\ typedef typename id2type::type type;\ }; # define BOOST_TYPEOF_NESTED_TYPEDEF(name,expr) \ struct name {\ BOOST_STATIC_CONSTANT(int,_typeof_register_value=sizeof(boost::type_of::typeof_register_type<name>(expr)));\ typedef boost::type_of::msvc_extract_type<name>::id2type id2type;\ typedef id2type::type type;\ }; #endif } } #endif//BOOST_TYPEOF_MSVC_TYPEOF_IMPL_HPP_INCLUDED