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+/*!
+@file
+Forward declares `boost::hana::power`.
+
+@copyright Louis Dionne 2013-2016
+Distributed under the Boost Software License, Version 1.0.
+(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
+ */
+
+#ifndef BOOST_HANA_FWD_POWER_HPP
+#define BOOST_HANA_FWD_POWER_HPP
+
+#include <boost/hana/config.hpp>
+#include <boost/hana/core/when.hpp>
+
+
+BOOST_HANA_NAMESPACE_BEGIN
+ //! Elevate a ring element to its `n`th power.
+ //! @ingroup group-Ring
+ //!
+ //! Specifically, `power(x, n)`, is equivalent to multiplying `x` with
+ //! itself `n` times using the Ring's multiplication. If the power is
+ //! equal to `zero`, the Ring's identity (`one`) is returned.
+ //!
+ //! @param x
+ //! A `Ring` element that is elevated to its `n`th power.
+ //!
+ //! @param n
+ //! A non-negative `IntegralConstant` representing the power to which `x`
+ //! is elevated.
+ //!
+ //!
+ //! @note
+ //! Only the tag of `x` is used for tag-dispatching.
+ //!
+ //! Example
+ //! -------
+ //! @include example/power.cpp
+#ifdef BOOST_HANA_DOXYGEN_INVOKED
+ constexpr auto power = [](auto&& x, auto const& n) -> decltype(auto) {
+ return tag-dispatched;
+ };
+#else
+ template <typename R, typename = void>
+ struct power_impl : power_impl<R, when<true>> { };
+
+ struct power_t {
+ template <typename X, typename N>
+ constexpr decltype(auto) operator()(X&& x, N const& n) const;
+ };
+
+ constexpr power_t power{};
+#endif
+BOOST_HANA_NAMESPACE_END
+
+#endif // !BOOST_HANA_FWD_POWER_HPP