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/*=============================================================================
Copyright (c) 2016 Lee Clagett
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)
==============================================================================*/
#ifndef FUSION_AND_07152016_1625
#define FUSION_AND_07152016_1625
#include <boost/config.hpp>
#include <boost/type_traits/integral_constant.hpp>
#if defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
#error fusion::detail::and_ requires variadic templates
#endif
namespace boost { namespace fusion { namespace detail {
template<typename ...Cond>
struct and_impl : false_type {};
template<typename ...T>
struct and_impl<integral_constant<T, true>...> : true_type {};
// This specialization is necessary to avoid MSVC-12 variadics bug.
template<bool ...Cond>
struct and_impl1 : and_impl<integral_constant<bool, Cond>...> {};
/* fusion::detail::and_ differs from mpl::and_ in the following ways:
- The empty set is valid and returns true
- A single element set is valid and returns the identity
- There is no upper bound on the set size
- The conditions are evaluated at once, and are not short-circuited. This
reduces instantations when returning true; the implementation is not
recursive. */
template<typename ...Cond>
struct and_ : and_impl1<Cond::value...> {};
}}}
#endif // FUSION_AND_07152016_1625
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