boost/multi_index/detail/vartempl_support.hpp
/* Copyright 2003-2013 Joaquin M Lopez Munoz.
* Distributed under the Boost Software License, Version 1.0.
* (See accompanying file LICENSE_1_0.txt or copy at
* http://www.boost.org/LICENSE_1_0.txt)
*
* See http://www.boost.org/libs/multi_index for library home page.
*/
#ifndef BOOST_MULTI_INDEX_DETAIL_VARTEMPL_SUPPORT_HPP
#define BOOST_MULTI_INDEX_DETAIL_VARTEMPL_SUPPORT_HPP
#if defined(_MSC_VER)&&(_MSC_VER>=1200)
#pragma once
#endif
/* Utilities for emulation of variadic template functions. Variadic packs are
* replaced by lists of BOOST_MULTI_INDEX_LIMIT_VARTEMPL_ARGS parameters:
*
* - typename... Args --> BOOST_MULTI_INDEX_TEMPLATE_PARAM_PACK
* - Args&&... args --> BOOST_MULTI_INDEX_FUNCTION_PARAM_PACK
* - std::forward<Args>(args)... --> BOOST_MULTI_INDEX_FORWARD_PARAM_PACK
*
* Forwarding emulated with Boost.Move. A template functions foo_imp
* defined in such way accepts *exactly* BOOST_MULTI_INDEX_LIMIT_VARTEMPL_ARGS
* arguments: variable number of arguments is emulated by providing a set of
* overloads foo forwarding to foo_impl with
*
* BOOST_MULTI_INDEX_OVERLOADS_TO_VARTEMPL
* BOOST_MULTI_INDEX_OVERLOADS_TO_VARTEMPL_EXTRA_ARG (initial extra arg)
*
* which fill the extra args with boost::multi_index::detail::noarg's.
* boost::multi_index::detail::vartempl_placement_new works the opposite
* way: it acceps a full a pointer x to Value and a
* BOOST_MULTI_INDEX_FUNCTION_PARAM_PACK and forwards to
* new(x) Value(args) where args is the argument pack after discarding
* noarg's.
*
* Emulation decays to the real thing when the compiler supports variadic
* templates and move semantics natively.
*/
#include <boost/config.hpp>
#if defined(BOOST_NO_CXX11_RVALUE_REFERENCES)||\
defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
#include <boost/move/core.hpp>
#include <boost/move/utility.hpp>
#include <boost/preprocessor/arithmetic/add.hpp>
#include <boost/preprocessor/arithmetic/sub.hpp>
#include <boost/preprocessor/cat.hpp>
#include <boost/preprocessor/control/if.hpp>
#include <boost/preprocessor/facilities/empty.hpp>
#include <boost/preprocessor/facilities/intercept.hpp>
#include <boost/preprocessor/logical/and.hpp>
#include <boost/preprocessor/punctuation/comma.hpp>
#include <boost/preprocessor/punctuation/comma_if.hpp>
#include <boost/preprocessor/repetition/enum.hpp>
#include <boost/preprocessor/repetition/enum_params.hpp>
#include <boost/preprocessor/repetition/repeat_from_to.hpp>
#include <boost/preprocessor/seq/elem.hpp>
#if !defined(BOOST_MULTI_INDEX_LIMIT_VARTEMPL_ARGS)
#define BOOST_MULTI_INDEX_LIMIT_VARTEMPL_ARGS 5
#endif
#define BOOST_MULTI_INDEX_TEMPLATE_PARAM_PACK \
BOOST_PP_ENUM_PARAMS( \
BOOST_MULTI_INDEX_LIMIT_VARTEMPL_ARGS,typename T)
#define BOOST_MULTI_INDEX_VARTEMPL_ARG(z,n,_) \
BOOST_FWD_REF(BOOST_PP_CAT(T,n)) BOOST_PP_CAT(t,n)
#define BOOST_MULTI_INDEX_FUNCTION_PARAM_PACK \
BOOST_PP_ENUM( \
BOOST_MULTI_INDEX_LIMIT_VARTEMPL_ARGS, \
BOOST_MULTI_INDEX_VARTEMPL_ARG,~)
#define BOOST_MULTI_INDEX_VARTEMPL_FORWARD_ARG(z,n,_) \
boost::forward<BOOST_PP_CAT(T,n)>(BOOST_PP_CAT(t,n))
#define BOOST_MULTI_INDEX_FORWARD_PARAM_PACK \
BOOST_PP_ENUM( \
BOOST_MULTI_INDEX_LIMIT_VARTEMPL_ARGS, \
BOOST_MULTI_INDEX_VARTEMPL_FORWARD_ARG,~)
namespace boost{namespace multi_index{namespace detail{
struct noarg{};
}}}
/* call vartempl function without args */
#define BOOST_MULTI_INDEX_NULL_PARAM_PACK \
BOOST_PP_ENUM_PARAMS( \
BOOST_MULTI_INDEX_LIMIT_VARTEMPL_ARGS, \
boost::multi_index::detail::noarg() BOOST_PP_INTERCEPT)
#define BOOST_MULTI_INDEX_TEMPLATE_N(n) \
template<BOOST_PP_ENUM_PARAMS(n,typename T)>
#define BOOST_MULTI_INDEX_TEMPLATE_0(n)
#define BOOST_MULTI_INDEX_OVERLOADS_TO_VARTEMPL_AUX(z,n,data) \
BOOST_PP_IF(n, \
BOOST_MULTI_INDEX_TEMPLATE_N, \
BOOST_MULTI_INDEX_TEMPLATE_0)(n) \
BOOST_PP_SEQ_ELEM(0,data) /* ret */ \
BOOST_PP_SEQ_ELEM(1,data) /* name_from */ ( \
BOOST_PP_ENUM(n,BOOST_MULTI_INDEX_VARTEMPL_ARG,~)) \
{ \
return BOOST_PP_SEQ_ELEM(2,data) /* name_to */ ( \
BOOST_PP_ENUM(n,BOOST_MULTI_INDEX_VARTEMPL_FORWARD_ARG,~) \
BOOST_PP_COMMA_IF( \
BOOST_PP_AND( \
n,BOOST_PP_SUB(BOOST_MULTI_INDEX_LIMIT_VARTEMPL_ARGS,n))) \
BOOST_PP_ENUM_PARAMS( \
BOOST_PP_SUB(BOOST_MULTI_INDEX_LIMIT_VARTEMPL_ARGS,n), \
boost::multi_index::detail::noarg() BOOST_PP_INTERCEPT) \
); \
}
#define BOOST_MULTI_INDEX_OVERLOADS_TO_VARTEMPL( \
ret,name_from,name_to) \
BOOST_PP_REPEAT_FROM_TO( \
0,BOOST_PP_ADD(BOOST_MULTI_INDEX_LIMIT_VARTEMPL_ARGS,1), \
BOOST_MULTI_INDEX_OVERLOADS_TO_VARTEMPL_AUX, \
(ret)(name_from)(name_to))
#define BOOST_MULTI_INDEX_OVERLOADS_TO_VARTEMPL_EXTRA_ARG_AUX( \
z,n,data) \
BOOST_PP_IF(n, \
BOOST_MULTI_INDEX_TEMPLATE_N, \
BOOST_MULTI_INDEX_TEMPLATE_0)(n) \
BOOST_PP_SEQ_ELEM(0,data) /* ret */ \
BOOST_PP_SEQ_ELEM(1,data) /* name_from */ ( \
BOOST_PP_SEQ_ELEM(3,data) BOOST_PP_SEQ_ELEM(4,data) /* extra arg */\
BOOST_PP_COMMA_IF(n) \
BOOST_PP_ENUM(n,BOOST_MULTI_INDEX_VARTEMPL_ARG,~)) \
{ \
return BOOST_PP_SEQ_ELEM(2,data) /* name_to */ ( \
BOOST_PP_SEQ_ELEM(4,data) /* extra_arg_name */ \
BOOST_PP_COMMA_IF(n) \
BOOST_PP_ENUM(n,BOOST_MULTI_INDEX_VARTEMPL_FORWARD_ARG,~) \
BOOST_PP_COMMA_IF( \
BOOST_PP_SUB(BOOST_MULTI_INDEX_LIMIT_VARTEMPL_ARGS,n)) \
BOOST_PP_ENUM_PARAMS( \
BOOST_PP_SUB(BOOST_MULTI_INDEX_LIMIT_VARTEMPL_ARGS,n), \
boost::multi_index::detail::noarg() BOOST_PP_INTERCEPT) \
); \
}
#define BOOST_MULTI_INDEX_OVERLOADS_TO_VARTEMPL_EXTRA_ARG( \
ret,name_from,name_to,extra_arg_type,extra_arg_name) \
BOOST_PP_REPEAT_FROM_TO( \
0,BOOST_PP_ADD(BOOST_MULTI_INDEX_LIMIT_VARTEMPL_ARGS,1), \
BOOST_MULTI_INDEX_OVERLOADS_TO_VARTEMPL_EXTRA_ARG_AUX, \
(ret)(name_from)(name_to)(extra_arg_type)(extra_arg_name))
namespace boost{
namespace multi_index{
namespace detail{
#define BOOST_MULTI_INDEX_VARTEMPL_TO_PLACEMENT_NEW_AUX(z,n,name) \
template< \
typename Value \
BOOST_PP_COMMA_IF(n) \
BOOST_PP_ENUM_PARAMS(n,typename T) \
> \
Value* name( \
Value* x \
BOOST_PP_COMMA_IF(n) \
BOOST_PP_ENUM(n,BOOST_MULTI_INDEX_VARTEMPL_ARG,~) \
BOOST_PP_COMMA_IF( \
BOOST_PP_SUB(BOOST_MULTI_INDEX_LIMIT_VARTEMPL_ARGS,n)) \
BOOST_PP_ENUM_PARAMS( \
BOOST_PP_SUB(BOOST_MULTI_INDEX_LIMIT_VARTEMPL_ARGS,n), \
BOOST_FWD_REF(noarg) BOOST_PP_INTERCEPT)) \
{ \
return new(x) Value( \
BOOST_PP_ENUM(n,BOOST_MULTI_INDEX_VARTEMPL_FORWARD_ARG,~)); \
}
#define BOOST_MULTI_INDEX_VARTEMPL_TO_PLACEMENT_NEW(name) \
BOOST_PP_REPEAT_FROM_TO( \
0,BOOST_PP_ADD(BOOST_MULTI_INDEX_LIMIT_VARTEMPL_ARGS,1), \
BOOST_MULTI_INDEX_VARTEMPL_TO_PLACEMENT_NEW_AUX, \
name)
BOOST_MULTI_INDEX_VARTEMPL_TO_PLACEMENT_NEW(vartempl_placement_new)
#undef BOOST_MULTI_INDEX_VARTEMPL_TO_PLACEMENT_NEW_AUX
#undef BOOST_MULTI_INDEX_VARTEMPL_TO_PLACEMENT_NEW
} /* namespace multi_index::detail */
} /* namespace multi_index */
} /* namespace boost */
#else
/* native variadic templates support */
#include <utility>
#define BOOST_MULTI_INDEX_TEMPLATE_PARAM_PACK typename... Args
#define BOOST_MULTI_INDEX_FUNCTION_PARAM_PACK Args&&... args
#define BOOST_MULTI_INDEX_FORWARD_PARAM_PACK std::forward<Args>(args)...
#define BOOST_MULTI_INDEX_NULL_PARAM_PACK
#define BOOST_MULTI_INDEX_OVERLOADS_TO_VARTEMPL( \
ret,name_from,name_to) \
template<typename... Args> ret name_from(Args&&... args) \
{ \
return name_to(std::forward<Args>(args)...); \
}
#define BOOST_MULTI_INDEX_OVERLOADS_TO_VARTEMPL_EXTRA_ARG( \
ret,name_from,name_to,extra_arg_type,extra_arg_name) \
template<typename... Args> ret name_from( \
extra_arg_type extra_arg_name,Args&&... args) \
{ \
return name_to(extra_arg_name,std::forward<Args>(args)...); \
}
namespace boost{
namespace multi_index{
namespace detail{
template<typename Value,typename... Args>
Value* vartempl_placement_new(Value*x,Args&&... args)
{
return new(x) Value(std::forward<Args>(args)...);
}
} /* namespace multi_index::detail */
} /* namespace multi_index */
} /* namespace boost */
#endif
#endif