forked from boostorg/mp11
72 lines
1.8 KiB
C++
72 lines
1.8 KiB
C++
#ifndef BOOST_MP11_UTILITY_HPP_INCLUDED
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#define BOOST_MP11_UTILITY_HPP_INCLUDED
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// Copyright 2015 Peter Dimov.
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//
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// Distributed under the Boost Software License, Version 1.0.
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//
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// See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt
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namespace boost
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{
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// mp_identity
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template<class T> struct mp_identity
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{
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using type = T;
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};
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// mp_inherit
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template<class... T> struct mp_inherit: T... {};
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// mp_if, mp_if_c
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namespace detail
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{
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template<bool C, class T, class E> struct mp_if_c_impl;
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template<class T, class E> struct mp_if_c_impl<true, T, E>
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{
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using type = T;
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};
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template<class T, class E> struct mp_if_c_impl<false, T, E>
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{
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using type = E;
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};
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} // namespace detail
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template<bool C, class T, class E> using mp_if_c = typename detail::mp_if_c_impl<C, T, E>::type;
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template<class C, class T, class E> using mp_if = typename detail::mp_if_c_impl<static_cast<bool>(C::value), T, E>::type;
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// mp_eval_if, mp_eval_if_c
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namespace detail
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{
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template<bool C, class T, template<class...> class F, class... U> struct mp_eval_if_c_impl;
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template<class T, template<class...> class F, class... U> struct mp_eval_if_c_impl<true, T, F, U...>
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{
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using type = T;
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};
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template<class T, template<class...> class F, class... U> struct mp_eval_if_c_impl<false, T, F, U...>
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{
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using type = F<U...>;
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};
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} // namespace detail
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template<bool C, class T, template<class...> class F, class... U> using mp_eval_if_c = typename detail::mp_eval_if_c_impl<C, T, F, U...>::type;
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template<class C, class T, template<class...> class F, class... U> using mp_eval_if = typename detail::mp_eval_if_c_impl<static_cast<bool>(C::value), T, F, U...>::type;
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// mp_valid
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// mp_defer
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// mp_defer_if_valid
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} // namespace boost
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#endif // #ifndef BOOST_MP11_UTILITY_HPP_INCLUDED
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