Imported Upstream version 1.67.0upstream/1.67.0

1 files changed, 89 insertions, 0 deletions

diff --git a/boost/type_erasure/detail/meta.hpp b/boost/type_erasure/detail/meta.hpp
new file mode 100644
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+++ b/boost/type_erasure/detail/meta.hpp
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+// Boost.TypeErasure library
+//
+// Copyright 2018 Steven Watanabe
+//
+// 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)
+//
+// $Id$
+
+#ifndef BOOST_TYPE_ERASURE_DETAIL_META_HPP_INCLUDED
+#define BOOST_TYPE_ERASURE_DETAIL_META_HPP_INCLUDED
+
+#include <boost/config.hpp>
+
+
+#if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) && \
+    !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES) && \
+    /* MSVC 14.0 breaks down in the template alias quagmire. */ \
+    !BOOST_WORKAROUND(BOOST_MSVC, <= 1900)
+
+#define BOOST_TYPE_ERASURE_USE_MP11
+
+#include <boost/mp11/list.hpp>
+#include <boost/mp11/map.hpp>
+#include <boost/mp11/set.hpp>
+#include <boost/mp11/algorithm.hpp>
+#include <boost/mp11/function.hpp>
+#include <boost/mp11/mpl.hpp>
+
+namespace boost {
+namespace type_erasure {
+namespace detail {
+
+struct mp11_list_inserter
+{
+    template<class L, class T>
+    using apply = ::boost::mpl::identity< ::boost::mp11::mp_push_back<L, T> >;
+};
+
+template<class T>
+struct make_mp_list_impl
+{
+    typedef typename ::boost::mpl::fold<
+        T,
+        ::boost::mp11::mp_list<>,
+        ::boost::type_erasure::detail::mp11_list_inserter
+    >::type type;
+};
+
+template<class... T>
+struct make_mp_list_impl< ::boost::mp11::mp_list<T...> >
+{
+    typedef ::boost::mp11::mp_list<T...> type;
+};
+
+template<class T>
+using make_mp_list = typename make_mp_list_impl<T>::type;
+
+template<bool>
+struct eval_if_impl;
+
+template<>
+struct eval_if_impl<true>
+{
+    template<template<class...> class T, template<class...> class F, class... A>
+    using apply = T<A...>;
+};
+
+template<>
+struct eval_if_impl<false>
+{
+    template<template<class...> class T, template<class...> class F, class... A>
+    using apply = F<A...>;
+};
+
+template<bool B, template<class...> class T, template<class...> class F, class... A>
+using eval_if = typename ::boost::type_erasure::detail::eval_if_impl<B>::template apply<T, F, A...>;
+
+template<class T0, class...>
+using first = T0;
+
+}
+}
+}
+
+#endif
+
+#endif