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) #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