Chris@102: /*=============================================================================
Chris@102:     Copyright (c) 2014 Eric Niebler
Chris@102:     Copyright (c) 2014 Kohei Takahashi
Chris@102: 
Chris@102:     Distributed under the Boost Software License, Version 1.0. (See accompanying 
Chris@102:     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@102: ==============================================================================*/
Chris@102: #if !defined(FUSION_SUPPORT_CONFIG_01092014_1718)
Chris@102: #define FUSION_SUPPORT_CONFIG_01092014_1718
Chris@102: 
Chris@102: #include <boost/config.hpp>
Chris@102: #include <boost/detail/workaround.hpp>
Chris@102: 
Chris@102: #ifndef BOOST_FUSION_GPU_ENABLED
Chris@102: #define BOOST_FUSION_GPU_ENABLED BOOST_GPU_ENABLED
Chris@102: #endif
Chris@102: 
Chris@102: // Enclose with inline namespace because unqualified lookup of GCC < 4.5 is broken.
Chris@102: //
Chris@102: //      namespace detail {
Chris@102: //          struct foo;
Chris@102: //          struct X { };
Chris@102: //      }
Chris@102: //
Chris@102: //      template <typename T> void foo(T) { }
Chris@102: //
Chris@102: //      int main()
Chris@102: //      {
Chris@102: //            foo(detail::X());
Chris@102: //            // prog.cc: In function 'int main()':
Chris@102: //            // prog.cc:2: error: 'struct detail::foo' is not a function,
Chris@102: //            // prog.cc:6: error: conflict with 'template<class T> void foo(T)'
Chris@102: //            // prog.cc:10: error: in call to 'foo'
Chris@102: //      }
Chris@102: namespace boost { namespace fusion { namespace detail
Chris@102: {
Chris@102:     namespace barrier { }
Chris@102:     using namespace barrier;
Chris@102: }}}
Chris@102: #define BOOST_FUSION_BARRIER_BEGIN namespace barrier {
Chris@102: #define BOOST_FUSION_BARRIER_END   }
Chris@102: 
Chris@102: 
Chris@102: #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1900))
Chris@102: // All of rvalue-reference ready MSVC don't perform implicit conversion from
Chris@102: // fundamental type to rvalue-reference of another fundamental type [1].
Chris@102: //
Chris@102: // Following example doesn't compile
Chris@102: //
Chris@102: //   int i;
Chris@102: //   long &&l = i; // sigh..., std::forward<long&&>(i) also fail.
Chris@102: //
Chris@102: // however, following one will work.
Chris@102: //
Chris@102: //   int i;
Chris@102: //   long &&l = static_cast<long &&>(i);
Chris@102: //
Chris@102: // OK, now can we replace all usage of std::forward to static_cast? -- I say NO!
Chris@102: // All of rvalue-reference ready Clang doesn't compile above static_cast usage [2], sigh...
Chris@102: //
Chris@102: // References:
Chris@102: // 1. https://connect.microsoft.com/VisualStudio/feedback/details/1037806/implicit-conversion-doesnt-perform-for-fund
Chris@102: // 2. http://llvm.org/bugs/show_bug.cgi?id=19917
Chris@102: //
Chris@102: // Tentatively, we use static_cast to forward if run under MSVC.
Chris@102: #   define BOOST_FUSION_FWD_ELEM(type, value) static_cast<type&&>(value)
Chris@102: #else
Chris@102: #   define BOOST_FUSION_FWD_ELEM(type, value) std::forward<type>(value)
Chris@102: #endif
Chris@102: 
Chris@102: 
Chris@102: // Workaround for LWG 2408: C++17 SFINAE-friendly std::iterator_traits.
Chris@102: // http://cplusplus.github.io/LWG/lwg-defects.html#2408
Chris@102: //
Chris@102: // - GCC 4.5 enables the feature under C++11.
Chris@102: //   https://gcc.gnu.org/ml/gcc-patches/2014-11/msg01105.html
Chris@102: //
Chris@102: // - MSVC 10.0 implements iterator intrinsics; MSVC 13.0 implements LWG2408.
Chris@102: #if (defined(BOOST_LIBSTDCXX_VERSION) && (BOOST_LIBSTDCXX_VERSION < 40500) && \
Chris@102:      defined(BOOST_LIBSTDCXX11)) || \
Chris@102:     (defined(BOOST_MSVC) && (1600 <= BOOST_MSVC || BOOST_MSVC < 1900))
Chris@102: #   define BOOST_FUSION_WORKAROUND_FOR_LWG_2408
Chris@102: namespace std
Chris@102: {
Chris@102:     template <typename>
Chris@102:     struct iterator_traits;
Chris@102: }
Chris@102: #endif
Chris@102: 
Chris@102: #endif