projects / ceph.git / blame
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| 7c673cae FG |
1 | /* Copyright 2006-2014 Joaquin M Lopez Munoz. |
| 2 | * Distributed under the Boost Software License, Version 1.0. | |
| 3 | * (See accompanying file LICENSE_1_0.txt or copy at | |
| 4 | * http://www.boost.org/LICENSE_1_0.txt) | |
| 5 | * | |
| 6 | * See http://www.boost.org/libs/flyweight for library home page. | |
| 7 | */ | |
| 8 | ||
| 9 | #ifndef BOOST_FLYWEIGHT_DETAIL_PERFECT_FWD_HPP | |
| 10 | #define BOOST_FLYWEIGHT_DETAIL_PERFECT_FWD_HPP | |
| 11 | ||
| 12 | #if defined(_MSC_VER) | |
| 13 | #pragma once | |
| 14 | #endif | |
| 15 | ||
| 16 | /* C++03-compatible implementation of perfect forwarding. | |
| 17 | * Usage: | |
| 18 | * | |
| 19 | * # define NAME ... | |
| 20 | * # define BODY(args) {...BOOST_FLYWEIGHT_FORWARD(args)...} | |
| 21 | * BOOST_FLYWEIGHT_PERFECT_FWD(name,body) | |
| 22 | * | |
| 23 | * where NAME includes the return type and qualifiers (if any) and BODY(args) | |
| 24 | * is expected to fo the forwarding through BOOST_FLYWEIGHT_FORWARD(args). | |
| 25 | * | |
| 26 | * In compilers capable of perfect forwarding, the real thing is provided | |
| 27 | * (just one variadic args overload is generated). Otherwise the machinery | |
| 28 | * generates n+1 overloads, if rvalue refs are supported, or else 2^(n+1)-1 | |
| 29 | * overloads accepting any combination of lvalue refs and const lvalue refs, | |
| 30 | * up to BOOST_FLYWEIGHT_LIMIT_PERFECT_FWD_ARGS args. | |
| 31 | * | |
| 32 | * BOOST_FLYWEIGHT_PERFECT_FWD_WITH_ARGS(name,body) is a variation omitting the | |
| 33 | * overloads with zero args --when perfect forwarding is available, this second | |
| 34 | * macro is exactly the same as the original. | |
| 35 | */ | |
| 36 | ||
| 37 | #include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */ | |
| 38 | #include <boost/preprocessor/cat.hpp> | |
| 39 | #include <boost/preprocessor/repetition/enum.hpp> | |
| 40 | #include <boost/preprocessor/repetition/enum_params.hpp> | |
| 41 | #include <boost/preprocessor/seq/seq.hpp> | |
| 42 | ||
| 43 | #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES) | |
| 44 | #include <utility> | |
| 45 | #endif | |
| 46 | ||
| 47 | #define BOOST_FLYWEIGHT_FORWARD_FORWARD_AUX(z,n,_) \ | |
| 48 | std::forward<BOOST_PP_CAT(T,n)>(BOOST_PP_CAT(t,n)) | |
| 49 | ||
| 50 | #define BOOST_FLYWEIGHT_FORWARD_FORWARD(n) \ | |
| 51 | BOOST_PP_ENUM(n,BOOST_FLYWEIGHT_FORWARD_FORWARD_AUX,~) | |
| 52 | ||
| 53 | #define BOOST_FLYWEIGHT_FORWARD_ENUM(n) BOOST_PP_ENUM_PARAMS(n,t) | |
| 54 | ||
| 55 | #define BOOST_FLYWEIGHT_FORWARD_PASS(arg) arg | |
| 56 | ||
| 57 | #define BOOST_FLYWEIGHT_FORWARD(args)\ | |
| 58 | BOOST_PP_CAT(BOOST_FLYWEIGHT_FORWARD_,BOOST_PP_SEQ_HEAD(args))( \ | |
| 59 | BOOST_PP_SEQ_HEAD(BOOST_PP_SEQ_TAIL(args))) | |
| 60 | ||
| 61 | #if defined(BOOST_NO_CXX11_RVALUE_REFERENCES)||\ | |
| 62 | defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) | |
| 63 | ||
| 64 | #if !defined(BOOST_FLYWEIGHT_LIMIT_PERFECT_FWD_ARGS) | |
| 65 | #define BOOST_FLYWEIGHT_LIMIT_PERFECT_FWD_ARGS 5 | |
| 66 | #endif | |
| 67 | ||
| 68 | #if BOOST_FLYWEIGHT_LIMIT_PERFECT_FWD_ARGS<0 | |
| 69 | #error BOOST_FLYWEIGHT_LIMIT_PERFECT_FWD_ARGS must be >=0 | |
| 70 | #endif | |
| 71 | ||
| 72 | #if BOOST_FLYWEIGHT_LIMIT_PERFECT_FWD_ARGS<=5 | |
| 73 | #include <boost/flyweight/detail/pp_perfect_fwd.hpp> | |
| 74 | #else | |
| 75 | #include <boost/flyweight/detail/dyn_perfect_fwd.hpp> | |
| 76 | #endif | |
| 77 | ||
| 78 | #else | |
| 79 | ||
| 80 | /* real perfect forwarding */ | |
| 81 | ||
| 82 | #define BOOST_FLYWEIGHT_PERFECT_FWD(name,body) \ | |
| 83 | template<typename... Args>name(Args&&... args) \ | |
| 84 | body((PASS)(std::forward<Args>(args)...)) | |
| 85 | ||
| 86 | #define BOOST_FLYWEIGHT_PERFECT_FWD_WITH_ARGS \ | |
| 87 | BOOST_FLYWEIGHT_PERFECT_FWD | |
| 88 | ||
| 89 | #endif | |
| 90 | #endif |