template_encoding.hpp

[2005最新C++经典著作].C++ Programming.新手必看的学VC的奠基之著。

// Copyright (C) 2004 Arkadiy Vertleyb
// Use, modification and distribution is subject to the Boost Software
// License, Version 1.0. (http://www.boost.org/LICENSE_1_0.txt)

#ifndef BOOST_TEMPLATE_ENCODING_HPP_INCLUDED
#define BOOST_TEMPLATE_ENCODING_HPP_INCLUDED

#include <boost/spirit/typeof/encode_decode.hpp>
#include <boost/spirit/typeof/int_encoding.hpp>

#include <boost/preprocessor/cat.hpp>
#include <boost/preprocessor/seq.hpp>
#include <boost/preprocessor/repetition/enum_trailing.hpp>

//////////

#define BOOST_TYPEOF_REGISTER_TEMPLATE_class_ BOOST_TYPEOF_REGISTER_TEMPLATE_typename_
#define BOOST_TYPEOF_REGISTER_TEMPLATE_typename_        (typename)  (void)  (TYPE)
#define BOOST_TYPEOF_REGISTER_TEMPLATE_integral(x)      (x)         (x)     (VALUE)

#define BOOST_TYPEOF_REGISTER_TEMPLATE_RESULT_TYPE(x) typename x::type
#define BOOST_TYPEOF_REGISTER_TEMPLATE_RESULT_VALUE(x) x::value

//////////

#define BOOST_TYPEOF_REGISTER_TEMPLATE_char_     BOOST_TYPEOF_REGISTER_TEMPLATE_integral(char)
#define BOOST_TYPEOF_REGISTER_TEMPLATE_short_    BOOST_TYPEOF_REGISTER_TEMPLATE_integral(short)
#define BOOST_TYPEOF_REGISTER_TEMPLATE_int_      BOOST_TYPEOF_REGISTER_TEMPLATE_integral(int)
#define BOOST_TYPEOF_REGISTER_TEMPLATE_long_     BOOST_TYPEOF_REGISTER_TEMPLATE_integral(long)
#define BOOST_TYPEOF_REGISTER_TEMPLATE_bool_     BOOST_TYPEOF_REGISTER_TEMPLATE_integral(bool)
#define BOOST_TYPEOF_REGISTER_TEMPLATE_unsigned_ BOOST_TYPEOF_REGISTER_TEMPLATE_integral(unsigned)

#define BOOST_TYPEOF_REGISTER_TEMPLATE_unsignedchar     BOOST_TYPEOF_REGISTER_TEMPLATE_integral(unsigned char)
#define BOOST_TYPEOF_REGISTER_TEMPLATE_unsignedshort    BOOST_TYPEOF_REGISTER_TEMPLATE_integral(unsigned short)
#define BOOST_TYPEOF_REGISTER_TEMPLATE_unsignedint      BOOST_TYPEOF_REGISTER_TEMPLATE_integral(unsigned int)
#define BOOST_TYPEOF_REGISTER_TEMPLATE_unsignedlong     BOOST_TYPEOF_REGISTER_TEMPLATE_integral(unsigned long)

//////////

#define BOOST_TYPEOF_TO_SEQ(tokens) BOOST_TYPEOF_ ## tokens ## _BOOST_TYPEOF 

#define BOOST_TYPEOF_unsigned (unsigned)

#define BOOST_TYPEOF_char_BOOST_TYPEOF (char)(_)
#define BOOST_TYPEOF_short_BOOST_TYPEOF (short)(_)
#define BOOST_TYPEOF_int_BOOST_TYPEOF (int)(_)
#define BOOST_TYPEOF_long_BOOST_TYPEOF (long)(_)
#define BOOST_TYPEOF_bool_BOOST_TYPEOF (bool)(_)
#define BOOST_TYPEOF_class_BOOST_TYPEOF (class)(_)
#define BOOST_TYPEOF_typename_BOOST_TYPEOF (typename)(_)
#define BOOST_TYPEOF_unsigned_BOOST_TYPEOF (unsigned)(_)

#define char_BOOST_TYPEOF (char)
#define short_BOOST_TYPEOF (short)
#define int_BOOST_TYPEOF (int)
#define long_BOOST_TYPEOF (long)

#define EAT_SPACE(tokens) BOOST_PP_CAT(BOOST_PP_SEQ_ELEM(0, BOOST_TYPEOF_TO_SEQ(tokens)), BOOST_PP_SEQ_ELEM(1, BOOST_TYPEOF_TO_SEQ(tokens)))

///////////

#define BOOST_TYPEOF_REGISTER_TEMPLATE_PARAM_DESCR(n, Params)\
    BOOST_PP_CAT(BOOST_TYPEOF_REGISTER_TEMPLATE_, EAT_SPACE(BOOST_PP_SEQ_ELEM(n, Params)))

#define BOOST_TYPEOF_REGISTER_TEMPLATE_PARAM_TYPE(n, Params)\
    BOOST_PP_SEQ_ELEM(0, BOOST_TYPEOF_REGISTER_TEMPLATE_PARAM_DESCR(n, Params))

#define BOOST_TYPEOF_REGISTER_TEMPLATE_PARAM_SPEC_TYPE(n, Params)\
    BOOST_PP_SEQ_ELEM(1, BOOST_TYPEOF_REGISTER_TEMPLATE_PARAM_DESCR(n, Params))

#define BOOST_TYPEOF_REGISTER_TEMPLATE_PARAM_RESULT(n, Params)\
    BOOST_PP_CAT(\
        BOOST_TYPEOF_REGISTER_TEMPLATE_RESULT_,\
        BOOST_PP_SEQ_ELEM(2, BOOST_TYPEOF_REGISTER_TEMPLATE_PARAM_DESCR(n, Params))\
    )

//////////

#define BOOST_TYPEOF_REGISTER_TEMPLATE_PARAM_PAIR(z, n, Params)\
    BOOST_TYPEOF_REGISTER_TEMPLATE_PARAM_TYPE(n, Params) BOOST_PP_CAT(P, n)

#define BOOST_TYPEOF_REGISTER_TEMPLATE_ENCODE_PARAM(z, n, Params)\
    typedef typename encode_dispatcher<\
        BOOST_TYPEOF_REGISTER_TEMPLATE_PARAM_SPEC_TYPE(n, Params)\
    >::encode<BOOST_PP_CAT(V, n), BOOST_PP_CAT(P, n)>::type BOOST_PP_CAT(V, BOOST_PP_INC(n));

#define BOOST_TYPEOF_REGISTER_TEMPLATE_DECODE_PARAM(z, n, Params)\
    typedef encode_dispatcher<\
        BOOST_TYPEOF_REGISTER_TEMPLATE_PARAM_SPEC_TYPE(n, Params)\
    >::decode<BOOST_PP_CAT(iter, n)> BOOST_PP_CAT(d, BOOST_PP_INC(n));\
    typedef typename BOOST_PP_CAT(d, BOOST_PP_INC(n))::iter BOOST_PP_CAT(iter, BOOST_PP_INC(n));

#define BOOST_TYPEOF_REGISTER_TEMPLATE_DECODE_PARAM_RESULT(z, n, Params)\
    BOOST_TYPEOF_REGISTER_TEMPLATE_PARAM_RESULT(n, Params)(BOOST_PP_CAT(d, BOOST_PP_INC(n)))

//////////

#define BOOST_TYPEOF_REGISTER_TEMPLATE_X_IMPL(Name, Params, ID)\
    namespace boost{namespace type_of{namespace{\
    template<class V\
        BOOST_PP_ENUM_TRAILING(\
            BOOST_PP_SEQ_SIZE(Params),\
            BOOST_TYPEOF_REGISTER_TEMPLATE_PARAM_PAIR,\
            Params)\
    >\
    struct encode_type_impl<V, Name<\
        BOOST_PP_ENUM_PARAMS(\
        BOOST_PP_SEQ_SIZE(Params),\
        P)> >\
    {\
        typedef typename BOOST_TYPEOF_PUSH_BACK<V, mpl::size_t<ID> >::type V0;\
        BOOST_PP_REPEAT(\
            BOOST_PP_SEQ_SIZE(Params),\
            BOOST_TYPEOF_REGISTER_TEMPLATE_ENCODE_PARAM,\
            Params)\
        typedef BOOST_PP_CAT(V, BOOST_PP_SEQ_SIZE(Params)) type;\
    };\
    template<class Iter>\
    struct decode_type_impl<boost::mpl::size_t<ID>, Iter>\
    {\
        typedef Iter iter0;\
        BOOST_PP_REPEAT(\
            BOOST_PP_SEQ_SIZE(Params),\
            BOOST_TYPEOF_REGISTER_TEMPLATE_DECODE_PARAM,\
            Params)\
        typedef Name<\
            BOOST_PP_ENUM(\
                BOOST_PP_SEQ_SIZE(Params),\
                BOOST_TYPEOF_REGISTER_TEMPLATE_DECODE_PARAM_RESULT,\
                Params)\
        > type;\
        typedef BOOST_PP_CAT(iter, BOOST_PP_SEQ_SIZE(Params)) iter;\
    };\
    }}}

#define BOOST_TYPEOF_REGISTER_TEMPLATE_X(Name, Params)\
    BOOST_TYPEOF_REGISTER_TEMPLATE_X_IMPL(Name, Params, BOOST_TYPEOF_UNIQUE_ID())

#define BOOST_TYPEOF_REGISTER_TEMPLATE_TYPE_PARAM_(z, n, data) (typename)

#define BOOST_TYPEOF_REGISTER_TEMPLATE(Name, n)\
    BOOST_TYPEOF_REGISTER_TEMPLATE_X(Name,\
        BOOST_PP_REPEAT(n, BOOST_TYPEOF_REGISTER_TEMPLATE_TYPE_PARAM_, ~)\
    )

//////////

#define BOOST_TYPEOF_spec_integral_dispatcher(r, data, T)   \
    template<> struct encode_dispatcher<T>                  \
    {                                                       \
        template<class V, T n>                              \
            struct encode : encode_integral<V, T, n>        \
        {};                                                 \
        template<class Iter>                                \
            struct decode : decode_integral<T, Iter>        \
        {};                                                 \
    };

namespace boost
{
    namespace type_of
    {
        template<class U = void> struct encode_dispatcher
        {
            template<class V, class T> 
                struct encode : encode_type<V, T>
            {};
            template<class Iter> 
                struct decode : decode_type<Iter>
            {};
        };

        BOOST_PP_SEQ_FOR_EACH(BOOST_TYPEOF_spec_integral_dispatcher, ~, 
            (char)
            (short)
            (int)
            (long)
            (bool)
            (unsigned char)
            (unsigned short)
            (unsigned int)
            (unsigned long)
            )
    }
}

#undef BOOST_TYPEOF_spec_integral_dispatcher

#endif//BOOST_TEMPLATE_ENCODING_HPP_INCLUDED