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Improve the BOOST_FUSION_ADAPT_STRUCT macro to work also when there is no variadic support.

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This enable the following flexible macro signature when there is
no BOOST_PP_VARIADICS support:

BOOST_FUSION_ADAPT_STRUCT(
    struct_name,
    (member_type0, member_name0)
    (BOOST_FUSION_ADAPT_AUTO, member_name1)
    (,member_name2)
    ...
    )

If BOOST_PP_VARIADICS is active then there is quite more flexibility as it
allows to avoid the type specification:

BOOST_FUSION_ADAPT_STRUCT(
    struct_name,
    (member_type0, member_name0)
    (BOOST_FUSION_ADAPT_AUTO, member_name1)
    (,member_name2)
    (member_name3)
    ...
    )
This commit is contained in:
Damien Buhl (alias daminetreg)
2014-05-30 17:44:49 +02:00
parent 944c363787
commit 37fc1443ad
1 changed files with 32 additions and 11 deletions
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43
include/boost/fusion/adapted/struct/adapt_struct.hpp
View File

@ -6,16 +6,17 @@
file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
==============================================================================*/
//#define BOOST_PP_VARIADICS
#ifndef BOOST_FUSION_ADAPTED_STRUCT_ADAPT_STRUCT_HPP
#define BOOST_FUSION_ADAPTED_STRUCT_ADAPT_STRUCT_HPP
#include <boost/fusion/support/config.hpp>
#include <boost/preprocessor/config/config.hpp>
#include <boost/preprocessor/variadic.hpp>
#include <boost/preprocessor/cat.hpp>
#include <boost/preprocessor/empty.hpp>
#include <boost/preprocessor/variadic.hpp>
#include <boost/preprocessor/control/if.hpp>
#include <boost/preprocessor/facilities/is_empty.hpp>
#include <boost/preprocessor/comparison/equal.hpp>
#include <boost/type_traits/add_reference.hpp>
#include <boost/type_traits/is_const.hpp>
#include <boost/type_traits/add_const.hpp>
@ -34,29 +35,49 @@
#include <boost/fusion/adapted/struct/detail/value_of_impl.hpp>
#include <boost/fusion/adapted/struct/detail/deref_impl.hpp>
//TODO: Write a variadic version full : with variadic also directly to provide the fields.
#if BOOST_PP_VARIADICS
#define BOOST_FUSION_ADAPT_STRUCT_CREATE_MEMBER_TUPLE(...) \
BOOST_PP_IF(BOOST_PP_EQUAL(BOOST_PP_VARIADIC_SIZE(__VA_ARGS__), 2), \
BOOST_PP_IF(BOOST_PP_IS_EMPTY(BOOST_PP_VARIADIC_ELEM(0, __VA_ARGS__)), \
((1, (BOOST_PP_VARIADIC_ELEM(1, __VA_ARGS__)) )), \
((2, BOOST_PP_VARIADIC_TO_TUPLE(__VA_ARGS__))) \
), \
((1, (BOOST_PP_VARIADIC_ELEM(0, __VA_ARGS__)) )) \
)
#define BOOST_FUSION_ADAPT_STRUCT_FILLER_0(...) \
((BOOST_PP_VARIADIC_SIZE(__VA_ARGS__), (__VA_ARGS__))) \
BOOST_FUSION_ADAPT_STRUCT_CREATE_MEMBER_TUPLE(__VA_ARGS__) \
BOOST_FUSION_ADAPT_STRUCT_FILLER_1
#define BOOST_FUSION_ADAPT_STRUCT_FILLER_1(...) \
((BOOST_PP_VARIADIC_SIZE(__VA_ARGS__), (__VA_ARGS__))) \
BOOST_FUSION_ADAPT_STRUCT_CREATE_MEMBER_TUPLE(__VA_ARGS__) \
BOOST_FUSION_ADAPT_STRUCT_FILLER_0
#define BOOST_FUSION_ADAPT_STRUCT_FILLER_0_END
#define BOOST_FUSION_ADAPT_STRUCT_FILLER_1_END
#else
#else // BOOST_PP_VARIADICS
#define BOOST_FUSION_ADAPT_STRUCT_CREATE_MEMBER_TUPLE(X, Y) \
BOOST_PP_IF(BOOST_PP_IS_EMPTY(X), \
((1, (Y))), \
((2, (X,Y))) \
)
#define BOOST_FUSION_ADAPT_STRUCT_FILLER_0(X, Y) \
((2, (X, Y))) BOOST_FUSION_ADAPT_STRUCT_FILLER_1
BOOST_FUSION_ADAPT_STRUCT_CREATE_MEMBER_TUPLE(X,Y) \
BOOST_FUSION_ADAPT_STRUCT_FILLER_1
#define BOOST_FUSION_ADAPT_STRUCT_FILLER_1(X, Y) \
((2, (X, Y))) BOOST_FUSION_ADAPT_STRUCT_FILLER_0
BOOST_FUSION_ADAPT_STRUCT_CREATE_MEMBER_TUPLE(X,Y) \
BOOST_FUSION_ADAPT_STRUCT_FILLER_0
#define BOOST_FUSION_ADAPT_STRUCT_FILLER_0_END
#define BOOST_FUSION_ADAPT_STRUCT_FILLER_1_END
#endif
#endif // BOOST_PP_VARIADICS
#define BOOST_FUSION_ADAPT_AUTO BOOST_PP_EMPTY()
#define BOOST_FUSION_ADAPT_STRUCT_C(TEMPLATE_PARAMS_SEQ, NAME_SEQ, I, ATTRIBUTE)\
BOOST_FUSION_ADAPT_STRUCT_C_BASE( \