// Copyright (C) 2007 Peder Holt | |
// 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> | |
namespace boost | |
{ | |
namespace type_of | |
{ | |
template<int N> struct encode_counter : encode_counter<N - 1> {}; | |
template<> struct encode_counter<0> {}; | |
char (*encode_index(...))[1]; | |
# define BOOST_TYPEOF_INDEX(T) (sizeof(*boost::type_of::encode_index((boost::type_of::encode_counter<1000>*)0))) | |
# define BOOST_TYPEOF_NEXT_INDEX(next) friend char (*encode_index(encode_counter<next>*))[next]; | |
//Typeof code | |
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, also works for Digital Mars | |
{ | |
typedef T type; | |
}; | |
}; | |
template<int ID> | |
struct msvc_typeid_wrapper { | |
typedef typename msvc_extract_type<mpl::int_<ID> >::id2type id2type; | |
typedef typename id2type::type 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]; | |
}; | |
template<typename T> | |
typename sizer<T>::type encode_start(T const&); | |
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//BOOST_TYPEOF_MSVC_TYPEOF_IMPL_HPP_INCLUDED |