1 /*============================================================================= 2 Copyright (c) 2012 Paul Fultz II 3 join.h 4 Distributed under the Boost Software License, Version 1.0. (See accompanying 5 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 6 ==============================================================================*/ 7 8 #ifndef BOOST_HOF_GUARD_FUNCTION_DETAIL_JOIN_H 9 #define BOOST_HOF_GUARD_FUNCTION_DETAIL_JOIN_H 10 11 #include <boost/hof/detail/holder.hpp> 12 13 namespace boost { namespace hof { namespace detail { 14 15 template<class... Ts> 16 struct join_args 17 {}; 18 19 template<template <class...> class T, class Args, class=void> 20 struct join_impl 21 {}; 22 23 template<template <class...> class T, class... Args> 24 struct join_impl<T, join_args<Args...>, typename holder< 25 T<Args...> 26 >::type> 27 { typedef T<Args...> type; }; 28 29 template<template <class...> class T, class... Args> 30 struct join 31 : join_impl<T, join_args<Args...>> 32 {}; 33 34 }}} // namespace boost::hof 35 36 #if defined(__GNUC__) && !defined (__clang__) && __GNUC__ == 4 && __GNUC_MINOR__ < 7 37 #define BOOST_HOF_JOIN(c, ...) typename boost::hof::detail::join<c, __VA_ARGS__>::type 38 #else 39 #define BOOST_HOF_JOIN(c, ...) c<__VA_ARGS__> 40 41 #endif 42 43 #endif 44