boost_mp11/include/boost/mp11/detail/config.hpp

#ifndef BOOST_MP11_DETAIL_CONFIG_HPP_INCLUDED
#define BOOST_MP11_DETAIL_CONFIG_HPP_INCLUDED

//  Copyright 2016 Peter Dimov.
//
//  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

#include <boost/config.hpp>
#include <boost/detail/workaround.hpp>

#if defined( BOOST_NO_CXX11_CONSTEXPR )

#  define BOOST_MP11_NO_CONSTEXPR

#elif defined( BOOST_MSVC ) && BOOST_WORKAROUND( BOOST_MSVC, < 1920 )

#  define BOOST_MP11_NO_CONSTEXPR

#endif

#if defined(__cpp_fold_expressions) && __cpp_fold_expressions >= 201603

#  define BOOST_MP11_HAS_FOLD_EXPRESSIONS

#elif defined(BOOST_CLANG) && defined(__has_cpp_attribute)
# if __has_cpp_attribute(fallthrough) && __cplusplus >= 201406L // Clang 3.9+ in c++1z mode

#  define BOOST_MP11_HAS_FOLD_EXPRESSIONS

# endif
#endif

#if defined(__has_builtin)
# if __has_builtin(__type_pack_element)

#  define BOOST_MP11_HAS_TYPE_PACK_ELEMENT

# endif
#endif

#endif // #ifndef BOOST_MP11_DETAIL_CONFIG_HPP_INCLUDED