1 /*============================================================================= 2 Copyright (c) 2014 Eric Niebler 3 Copyright (c) 2014,2015,2018 Kohei Takahashi 4 5 Distributed under the Boost Software License, Version 1.0. (See accompanying 6 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 7 ==============================================================================*/ 8 #if !defined(FUSION_SUPPORT_CONFIG_01092014_1718) 9 #define FUSION_SUPPORT_CONFIG_01092014_1718 10 11 #include <boost/config.hpp> 12 #include <boost/detail/workaround.hpp> 13 #include <utility> 14 15 #ifndef BOOST_FUSION_GPU_ENABLED 16 #define BOOST_FUSION_GPU_ENABLED BOOST_GPU_ENABLED 17 #endif 18 19 // Enclose with inline namespace because unqualified lookup of GCC < 4.5 is broken. 20 // 21 // namespace detail { 22 // struct foo; 23 // struct X { }; 24 // } 25 // 26 // template <typename T> void foo(T) { } 27 // 28 // int main() 29 // { 30 // foo(detail::X()); 31 // // prog.cc: In function 'int main()': 32 // // prog.cc:2: error: 'struct detail::foo' is not a function, 33 // // prog.cc:6: error: conflict with 'template<class T> void foo(T)' 34 // // prog.cc:10: error: in call to 'foo' 35 // } 36 namespace boost { namespace fusion { namespace detail 37 { 38 namespace barrier { } 39 using namespace barrier; 40 }}} 41 #define BOOST_FUSION_BARRIER_BEGIN namespace barrier { 42 #define BOOST_FUSION_BARRIER_END } 43 44 45 #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1900)) 46 // All of rvalue-reference ready MSVC don't perform implicit conversion from 47 // fundamental type to rvalue-reference of another fundamental type [1]. 48 // 49 // Following example doesn't compile 50 // 51 // int i; 52 // long &&l = i; // sigh..., std::forward<long&&>(i) also fail. 53 // 54 // however, following one will work. 55 // 56 // int i; 57 // long &&l = static_cast<long &&>(i); 58 // 59 // OK, now can we replace all usage of std::forward to static_cast? -- I say NO! 60 // All of rvalue-reference ready Clang doesn't compile above static_cast usage [2], sigh... 61 // 62 // References: 63 // 1. https://connect.microsoft.com/VisualStudio/feedback/details/1037806/implicit-conversion-doesnt-perform-for-fund 64 // 2. http://llvm.org/bugs/show_bug.cgi?id=19917 65 // 66 // Tentatively, we use static_cast to forward if run under MSVC. 67 # define BOOST_FUSION_FWD_ELEM(type, value) static_cast<type&&>(value) 68 #else 69 # define BOOST_FUSION_FWD_ELEM(type, value) std::forward<type>(value) 70 #endif 71 72 73 // Workaround for LWG 2408: C++17 SFINAE-friendly std::iterator_traits. 74 // http://cplusplus.github.io/LWG/lwg-defects.html#2408 75 // 76 // - GCC 4.5 enables the feature under C++11. 77 // https://gcc.gnu.org/ml/gcc-patches/2014-11/msg01105.html 78 // 79 // - MSVC 10.0 implements iterator intrinsics; MSVC 13.0 implements LWG2408. 80 #if (defined(BOOST_LIBSTDCXX_VERSION) && (BOOST_LIBSTDCXX_VERSION < 40500) && \ 81 defined(BOOST_LIBSTDCXX11)) || \ 82 (defined(BOOST_MSVC) && (1600 <= BOOST_MSVC && BOOST_MSVC < 1900)) 83 # define BOOST_FUSION_WORKAROUND_FOR_LWG_2408 84 namespace std 85 { 86 template <typename> 87 struct iterator_traits; 88 } 89 #endif 90 91 92 // Workaround for older GCC that doesn't accept `this` in constexpr. 93 #if BOOST_WORKAROUND(BOOST_GCC, < 40700) 94 #define BOOST_FUSION_CONSTEXPR_THIS 95 #else 96 #define BOOST_FUSION_CONSTEXPR_THIS BOOST_CONSTEXPR 97 #endif 98 99 100 // Workaround for compilers not implementing N3031 (DR743 and DR950). 101 #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1913)) || \ 102 BOOST_WORKAROUND(BOOST_GCC, < 40700) || \ 103 defined(BOOST_CLANG) && (__clang_major__ == 3 && __clang_minor__ == 0) 104 # if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES) 105 namespace boost { namespace fusion { namespace detail 106 { 107 template <typename T> 108 using type_alias_t = T; 109 }}} 110 # define BOOST_FUSION_DECLTYPE_N3031(parenthesized_expr) \ 111 boost::fusion::detail::type_alias_t<decltype parenthesized_expr> 112 # else 113 # include <boost/mpl/identity.hpp> 114 # define BOOST_FUSION_DECLTYPE_N3031(parenthesized_expr) \ 115 boost::mpl::identity<decltype parenthesized_expr>::type 116 # endif 117 #else 118 # define BOOST_FUSION_DECLTYPE_N3031(parenthesized_expr) \ 119 decltype parenthesized_expr 120 #endif 121 122 123 // Workaround for GCC 4.6 that rejects defaulted function with noexcept. 124 #if BOOST_WORKAROUND(BOOST_GCC, / 100 == 406) 125 # define BOOST_FUSION_NOEXCEPT_ON_DEFAULTED 126 #else 127 # define BOOST_FUSION_NOEXCEPT_ON_DEFAULTED BOOST_NOEXCEPT 128 #endif 129 130 #endif 131